Patent Publication Number: US-2023154129-A1

Title: Body normal network light and rendering control

Description:
PRIORITY CLAIM 
     This application claims the benefit of U.S. patent application Ser. No. 17/490,209, filed on Sep. 30, 2021, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates generally to providing augmented reality experiences using a messaging application. 
     BACKGROUND 
     Augmented Reality (AR) is a modification of a virtual environment. For example, in Virtual Reality (VR), a user is completely immersed in a virtual world, whereas in AR, the user is immersed in a world where virtual objects are combined or superimposed on the real world. An AR system aims to generate and present virtual objects that interact realistically with a real-world environment and with each other. Examples of AR applications can include single or multiple player video games, instant messaging systems, and the like. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced. Some nonlimiting examples are illustrated in the figures of the accompanying drawings in which: 
         FIG.  1    is a diagrammatic representation of a networked environment in which the present disclosure may be deployed, in accordance with some examples. 
         FIG.  2    is a diagrammatic representation of a messaging client application, in accordance with some examples. 
         FIG.  3    is a diagrammatic representation of a data structure as maintained in a database, in accordance with some examples. 
         FIG.  4    is a diagrammatic representation of a message, in accordance with some examples. 
         FIG.  5    is a block diagram showing an example AR fashion control system, according to example examples. 
         FIGS.  6 ,  7 , and  8    are diagrammatic representations of outputs of the AR fashion control system, in accordance with some examples. 
         FIG.  9    is a flowchart illustrating example operations of the AR fashion control system, according to some examples. 
         FIG.  10    is a diagrammatic representation of a machine in the form of a computer system within which a set of instructions may be executed for causing the machine to perform any one or more of the methodologies discussed herein, in accordance with some examples. 
         FIG.  11    is a block diagram showing a software architecture within which examples may be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     The description that follows includes systems, methods, techniques, instruction sequences, and computing machine program products that embody illustrative examples of the disclosure. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide an understanding of various examples. It will be evident, however, to those skilled in the art, that examples may be practiced without these specific details. In general, well-known instruction instances, protocols, structures, and techniques are not necessarily shown in detail. 
     Typically, VR and (AR) systems display images representing a given user by capturing an image of the user and, in addition, obtaining a depth map using a depth sensor of the real-world human body depicted in the image. By processing the depth map and the image together, the VR and AR systems can detect positioning of a user in the image and can appropriately modify the user or background in the images. While such systems work well, the need for a depth sensor limits the scope of their applications. This is because adding depth sensors to user devices for the purpose of modifying images increases the overall cost and complexity of the devices, making them less attractive. 
     Certain systems do away with the need to use depth sensors to modify images. For example, certain systems allow users to replace a background in a videoconference in which a face of the user is detected. Specifically, such systems can use specialized techniques that are optimized for recognizing a face of a user to identify the background in the images that depict the user&#39;s face. These systems can then replace only those pixels that depict the background so that the real-world background is replaced with an alternate background in the images. Such systems though are generally incapable of recognizing a whole body of a user. As such, if the user is more than a threshold distance from the camera such that more than just the face of the user is captured by the camera, the replacement of the background with an alternate background begins to fail. In such cases, the image quality is severely impacted, and portions of the face and body of the user can be inadvertently removed by the system as the system falsely identifies such portions as belonging to the background rather than the foreground of the images. Also, such systems fail to properly replace the background when more than one user is depicted in the image or video feed. Because such systems are generally incapable of distinguishing a whole body of a user in an image from a background, these systems are also unable to apply visual effects to certain portions of a user&#39;s body, such as articles of clothing. 
     The disclosed techniques improve the efficiency of using the electronic device by segmenting articles of clothing, fashion items, or garments worn by a user depicted in an image or video, such as a shirt worn by the user depicted in the image, in addition to creating a whole-body model of the user depicted in the image or video. By segmenting the articles of clothing, fashion items, or garments worn by a user or worn by different respective users depicted in an image and estimating pixel angles of the articles of clothing, fashion items, or garments relative to a camera or surface normal of the camera, the disclosed techniques can apply one or more visual effects to the image or video, such as one or more AR elements. In an example, the disclosed techniques can change lighting effects and reflections on articles of clothing, fashion items, or garments and can re-focus artificial or AR light being applied to such articles of clothing, fashion items, or garments from different directions. In another example, the disclosed techniques can change the materials of articles of clothing, fashion items, or garments so that light is being reflected and/or absorbed in different ways based on the direction and orientation of such articles of clothing, fashion items, or garments relative to the camera or surface normal of the camera. 
     In an example, the disclosed techniques apply a machine learning technique to generate a segmentation of a shirt (or upper garment) worn by a user depicted in an image (e.g., to distinguish pixels corresponding to the shirt or multiple garments worn by the user from pixels corresponding to a background of the image or a user&#39;s body parts). In this way, the disclosed techniques can apply one or more visual effects to the shirt worn by a user that has been segmented in the current image. Also, by generating the segmentation of the shirt, a position/location of the shirt in a video feed can be tracked independently or separately from positions of a user&#39;s body parts, such as a hand. As a result, a realistic display is provided that shows the user wearing a shirt (or upper garment) while also presenting AR elements on the shirt in a way that is intuitive for the user to interact with and select. As used herein, “article of clothing,” “fashion item,” and “garment” are used interchangeably and should be understood to have the same meaning. This improves the overall experience of the user in using the electronic device. Also, by performing such segmentations without using a depth sensor, the overall amount of system resources needed to accomplish a task is reduced. 
     Networked Computing Environment 
       FIG.  1    is a block diagram showing an example messaging system  100  for exchanging data (e.g., messages and associated content) over a network. The messaging system  100  includes multiple instances of a client device  102 , each of which hosts a number of applications, including a messaging client  104  and other external applications  109  (e.g., third-party applications). Each messaging client  104  is communicatively coupled to other instances of the messaging client  104  (e.g., hosted on respective other client devices  102 ), a messaging server system  108  and external app(s) servers  110  via a network  112  (e.g., the Internet). A messaging client  104  can also communicate with locally-hosted third-party applications, such as external apps  109  using Application Programming Interfaces (APIs). 
     A messaging client  104  is able to communicate and exchange data with other messaging clients  104  and with the messaging server system  108  via the network  112 . The data exchanged between messaging clients  104 , and between a messaging client  104  and the messaging server system  108 , includes functions (e.g., commands to invoke functions) as well as payload data (e.g., text, audio, video or other multimedia data). 
     The messaging server system  108  provides server-side functionality via the network  112  to a particular messaging client  104 . While certain functions of the messaging system  100  are described herein as being performed by either a messaging client  104  or by the messaging server system  108 , the location of certain functionality either within the messaging client  104  or the messaging server system  108  may be a design choice. For example, it may be technically preferable to initially deploy certain technology and functionality within the messaging server system  108  but to later migrate this technology and functionality to the messaging client  104  where a client device  102  has sufficient processing capacity. 
     The messaging server system  108  supports various services and operations that are provided to the messaging client  104 . Such operations include transmitting data to, receiving data from, and processing data generated by the messaging client  104 . This data may include message content, client device information, geolocation information, media augmentation and overlays, message content persistence conditions, social network information, and live event information, as examples. Data exchanges within the messaging system  100  are invoked and controlled through functions available via user interfaces of the messaging client  104 . 
     Turning now specifically to the messaging server system  108 , an API server  116  is coupled to, and provides a programmatic interface to, application servers  114 . The application servers  114  are communicatively coupled to a database server  120 , which facilitates access to a database  126  that stores data associated with messages processed by the application servers  114 . Similarly, a web server  128  is coupled to the application servers  114  and provides web-based interfaces to the application servers  114 . To this end, the web server  128  processes incoming network requests over the Hypertext Transfer Protocol (HTTP) and several other related protocols. 
     The API server  116  receives and transmits message data (e.g., commands and message payloads) between the client device  102  and the application servers  114 . Specifically, the API server  116  provides a set of interfaces (e.g., routines and protocols) that can be called or queried by the messaging client  104  in order to invoke functionality of the application servers  114 . The API server  116  exposes various functions supported by the application servers  114 , including account registration; login functionality; the sending of messages, via the application servers  114 , from a particular messaging client  104  to another messaging client  104 ; the sending of media files (e.g., images or video) from a messaging client  104  to a messaging server  118 , and for possible access by another messaging client  104 ; the settings of a collection of media data (e.g., story); the retrieval of a list of friends of a user of a client device  102 ; the retrieval of such collections; the retrieval of messages and content; the addition and deletion of entities (e.g., friends) to an entity graph (e.g., a social graph); the location of friends within a social graph; and opening an application event (e.g., relating to the messaging client  104 ). 
     The application servers  114  host a number of server applications and subsystems, including, for example, a messaging server  118 , an image processing server  122 , and a social network server  124 . The messaging server  118  implements a number of message processing technologies and functions, particularly related to the aggregation and other processing of content (e.g., textual and multimedia content) included in messages received from multiple instances of the messaging client  104 . As will be described in further detail, the text and media content from multiple sources may be aggregated into collections of content (e.g., called stories or galleries). These collections are then made available to the messaging client  104 . Other processor- and memory-intensive processing of data may also be performed server-side by the messaging server  118 , in view of the hardware requirements for such processing. 
     The application servers  114  also include an image processing server  122  that is dedicated to performing various image processing operations, typically with respect to images or video within the payload of a message sent from or received at the messaging server  118 . 
     Image processing server  122  is used to implement scan functionality of the augmentation system  208  (shown in  FIG.  2   ). Scan functionality includes activating and providing one or more AR experiences on a client device  102  when an image is captured by the client device  102 . Specifically, the messaging client  104  on the client device  102  can be used to activate a camera. The camera displays one or more real-time images or a video to a user along with one or more icons or identifiers of one or more AR experiences. The user can select a given one of the identifiers to launch the corresponding AR experience or perform a desired image modification (e.g., replacing a garment being worn by a user in a video or recoloring the garment worn by the user in the video or modifying the garment based on a gesture performed by the user). 
     The social network server  124  supports various social networking functions and services and makes these functions and services available to the messaging server  118 . To this end, the social network server  124  maintains and accesses an entity graph  308  (as shown in  FIG.  3   ) within the database  126 . Examples of functions and services supported by the social network server  124  include the identification of other users of the messaging system  100  with which a particular user has relationships or is “following,” and also the identification of other entities and interests of a particular user. 
     Returning to the messaging client  104 , features and functions of an external resource (e.g., a third-party application  109  or applet) are made available to a user via an interface of the messaging client  104 . The messaging client  104  receives a user selection of an option to launch or access features of an external resource (e.g., a third-party resource), such as external apps  109 . The external resource may be a third-party application (external apps  109 ) installed on the client device  102  (e.g., a “native app”), or a small-scale version of the third-party application (e.g., an “applet”) that is hosted on the client device  102  or remote of the client device  102  (e.g., on third-party servers  110 ). The small-scale version of the third-party application includes a subset of features and functions of the third-party application (e.g., the full-scale, native version of the third-party standalone application) and is implemented using a markup-language document. In one example, the small-scale version of the third-party application (e.g., an “applet”) is a web-based, markup-language version of the third-party application and is embedded in the messaging client  104 . In addition to using markup-language documents (e.g., a .*ml file), an applet may incorporate a scripting language (e.g., a .*js file or a .json file) and a style sheet (e.g., a.*ss file). 
     In response to receiving a user selection of the option to launch or access features of the external resource (external app  109 ), the messaging client  104  determines whether the selected external resource is a web-based external resource or a locally-installed external application. In some cases, external applications  109  that are locally installed on the client device  102  can be launched independently of and separately from the messaging client  104 , such as by selecting an icon, corresponding to the external application  109 , on a home screen of the client device  102 . Small-scale versions of such external applications can be launched or accessed via the messaging client  104  and, in some examples, no or limited portions of the small-scale external application can be accessed outside of the messaging client  104 . The small-scale external application can be launched by the messaging client  104  receiving, from an external app(s) server  110 , a markup-language document associated with the small-scale external application and processing such a document. 
     In response to determining that the external resource is a locally-installed external application  109 , the messaging client  104  instructs the client device  102  to launch the external application  109  by executing locally-stored code corresponding to the external application  109 . In response to determining that the external resource is a web-based resource, the messaging client  104  communicates with the external app(s) servers  110  to obtain a markup-language document corresponding to the selected resource. The messaging client  104  then processes the obtained markup-language document to present the web-based external resource within a user interface of the messaging client  104 . 
     The messaging client  104  can notify a user of the client device  102 , or other users related to such a user (e.g., “friends”), of activity taking place in one or more external resources. For example, the messaging client  104  can provide participants in a conversation (e.g., a chat session) in the messaging client  104  with notifications relating to the current or recent use of an external resource by one or more members of a group of users. One or more users can be invited to join in an active external resource or to launch a recently-used but currently inactive (in the group of friends) external resource. The external resource can provide participants in a conversation, each using a respective messaging client  104 , with the ability to share an item, status, state, or location in an external resource with one or more members of a group of users into a chat session. The shared item may be an interactive chat card with which members of the chat can interact, for example, to launch the corresponding external resource, view specific information within the external resource, or take the member of the chat to a specific location or state within the external resource. Within a given external resource, response messages can be sent to users on the messaging client  104 . The external resource can selectively include different media items in the responses, based on a current context of the external resource. 
     The messaging client  104  can present a list of the available external resources (e.g., third-party or external applications  109  or applets) to a user to launch or access a given external resource. This list can be presented in a context-sensitive menu. For example, the icons representing different ones of the external application  109  (or applets) can vary based on how the menu is launched by the user (e.g., from a conversation interface or from a non-conversation interface). 
     The messaging client  104  can present to a user one or more AR experiences that can be controlled and presented on an article of clothing, such as a shirt (fashion item or upper garment), worn by a person (or user) depicted in the image. As an example, the messaging client  104  can detect a person in an image or video captured by the client device  102 . The messaging client  104  can segment an article of clothing (or fashion item), such as a shirt, in the image or video. While the disclosed examples are discussed in relation to a shirt worn by a person (or user of the client device  102 ) depicted in an image or video, similar techniques can be applied to any other article of clothing, upper garment, or fashion item, such as a dress, pants, shorts, skirts, jackets, t-shirts, blouses, glasses, jewelry, a hat, ear muffs, and so forth. 
     In response to segmenting the shirt, the messaging client  104  can extract an image portion corresponding to the segmented shirt. The extracted image portion can be processed by a trained machine learning technique (e.g., a neural network) to estimate an angle of each pixel in the image portion relative to a camera used to capture the image, such as relative to a surface normal of the camera used to capture the image or video. This enables the messaging client  104  to present one or more AR elements on the shirt depicted in the image based on the estimated angle of each pixel in the portion of the image relative to the camera used to capture the image. 
     In one example, the messaging client  104  can determine that light is being focused on the fashion item (shirt or upper garment) from a first direction based on the estimated angle of each pixel. In response, the messaging client  104  can modify pixel values of the portion of the fashion item to re-focus the light on the fashion item from a second direction based on the estimated angle of each pixel. Specifically, the messaging client  104  can determine that a first pixel in the portion of the image is pointing towards a given direction relative to the camera or surface normal of the camera. In such cases, the messaging client  104  can modify the first pixel to render a reflection of the re-focused light from the second direction towards the given direction. 
     For example, the light in the image depicting the fashion item can be focused from a top of the image towards a bottom of the image. Namely, a spotlight can be presented above the person depicted in the image and can point downwards towards the floor depicted in the image. In such cases, the messaging client  104  can modify the pixel values to re-focus artificial light from the bottom towards the top. For example, the messaging client  104  can remove the spotlight or light coming from the top of the image depicting the person and can render a display of AR light originating from a floor depicted in the image. The messaging client  104  can control reflections off of a fashion item or clothing worn by the person depicted in the image based on the estimated angle of each pixel corresponding to the fashion item relative to the camera. Specifically, the messaging client  104  can determine how light that is directed towards each given pixel of the fashion item is reflected or absorbed based on the corresponding angle of each pixel relative to the camera and based on the angle of each pixel relative to the point of origin of the AR light. This creates a realistic illusion that light is originating from a bottom of the image as the manner of reflection and absorption of the light on the fashion item worn by the person depicted in the image is preserved. 
     In some examples, the messaging client  104  can select or receive a selection of an AR material for the fashion item and can replace a material of the fashion item with the AR material based on the estimated angle of each pixel. In one example, the messaging client  104  can display a list of different AR materials and can receive a selection of the AR material from the list. The selection can be made verbally using speech input from the user or by receiving touch input from the user touching a particular one of the AR materials in the list. 
     Specifically, the messaging client  104  can determine a light reflection or absorption property of the AR material. In response, the messaging client  104  can, for each pixel in the portion of the image, compute a new pixel value based on the light reflection or absorption property of the AR material and the estimated angle of the pixel. In this way, the messaging client  104  can apply different AR shades to the fashion item depicted in the image or video for each different type of the AR material that is selected. In one example, the fashion item worn by the person depicted in the image or video can be made of a cloth or cloth-like material and the messaging client  104  can replace the cloth or cloth-like material with an AR material, such as gold, mirror, metal, water, or slime. In such cases, the light reflection and/or absorption properties of the fashion item worn by the person depicted in the image or video is changed to correspond to the light reflection and/or absorption properties of the AR material. To perform such AR changes, the messaging client  104  can modify each pixel value of the portion of the image that corresponds to the fashion item based on the estimated angle of the corresponding pixel relative to the camera. The value of the pixel of the portion of the fashion item represents the direction at which light is reflected or absorbed by that portion of the fashion item made of the AR material and differs from the direction at which light is reflected or absorbed by that portion of the fashion item made by the cloth or cloth-like material. 
     The messaging client  104  continuously or periodically recomputes and re-estimates the angle of each pixel in the portion of the image corresponding to the fashion item. Specifically, the messaging client  104  can track movement of the person depicted in the image or video across frames of the image or video. As the person moves, the messaging client  104  can recompute and re-estimate the angle of each pixel in the portion of the image corresponding to the fashion item. The messaging client  104  can continuously or periodically modify the AR elements presented on the fashion item and specifically modify the way in which light is reflected or absorbed by the pixels corresponding to the fashion item based on changes to the angle of each pixel. 
     In some implementations, the messaging client  104  can apply a neural network to the portion of the image corresponding to the fashion item to estimate the angle of each pixel relative to the surface normal of the camera used to capture the image or video. The neural network can be trained to establish a relationship between image portions depicting different orientations of fashion items and pixel directions of the fashion items relative to surface normals of cameras used to capture the image portions. As another example, the neural network can be trained to establish a relationship between image portions depicting reflections of light from different directions on fashion items and pixel directions of the fashion items relative to surface normals of cameras used to capture the image portions. As another example, the neural network can be trained to estimate lighting conditions for each pixel in the portion when the AR light is applied from a new direction (a direction specified in input received from a user). In such cases, the neural network is trained to establish a relationship between image portions depicting focusing of light on fashion items from different directions and lighting conditions of pixels of the fashion items. 
     System Architecture 
       FIG.  2    is a block diagram illustrating further details regarding the messaging system  100 , according to some examples. Specifically, the messaging system  100  is shown to comprise the messaging client  104  and the application servers  114 . The messaging system  100  embodies a number of subsystems, which are supported on the client side by the messaging client  104  and on the sever side by the application servers  114 . These subsystems include, for example, an ephemeral timer system  202 , a collection management system  204 , an augmentation system  208 , a map system  210 , a game system  212 , and an external resource system  220 . 
     The ephemeral timer system  202  is responsible for enforcing the temporary or time-limited access to content by the messaging client  104  and the messaging server  118 . The ephemeral timer system  202  incorporates a number of timers that, based on duration and display parameters associated with a message, or collection of messages (e.g., a story), selectively enable access (e.g., for presentation and display) to messages and associated content via the messaging client  104 . Further details regarding the operation of the ephemeral timer system  202  are provided below. 
     The collection management system  204  is responsible for managing sets or collections of media (e.g., collections of text, image video, and audio data). A collection of content (e.g., messages, including images, video, text, and audio) may be organized into an “event gallery” or an “event story.” Such a collection may be made available for a specified time period, such as the duration of an event to which the content relates. For example, content relating to a music concert may be made available as a “story” for the duration of that music concert. The collection management system  204  may also be responsible for publishing an icon that provides notification of the existence of a particular collection to the user interface of the messaging client  104 . 
     The collection management system  204  further includes a curation interface  206  that allows a collection manager to manage and curate a particular collection of content. For example, the curation interface  206  enables an event organizer to curate a collection of content relating to a specific event (e.g., delete inappropriate content or redundant messages). Additionally, the collection management system  204  employs machine vision (or image recognition technology) and content rules to automatically curate a content collection. In certain examples, compensation may be paid to a user for the inclusion of user-generated content into a collection. In such cases, the collection management system  204  operates to automatically make payments to such users for the use of their content. 
     The augmentation system  208  provides various functions that enable a user to augment (e.g., annotate or otherwise modify or edit) media content associated with a message. For example, the augmentation system  208  provides functions related to the generation and publishing of media overlays for messages processed by the messaging system  100 . The augmentation system  208  operatively supplies a media overlay or augmentation (e.g., an image filter) to the messaging client  104  based on a geolocation of the client device  102 . In another example, the augmentation system  208  operatively supplies a media overlay to the messaging client  104  based on other information, such as social network information of the user of the client device  102 . A media overlay may include audio and visual content and visual effects. Examples of audio and visual content include pictures, texts, logos, animations, and sound effects. An example of a visual effect includes color overlaying. The audio and visual content or the visual effects can be applied to a media content item (e.g., a photo) at the client device  102 . For example, the media overlay may include text, a graphical element, or image that can be overlaid on top of a photograph taken by the client device  102 . In another example, the media overlay includes an identification of a location overlay (e.g., Venice beach), a name of a live event, or a name of a merchant overlay (e.g., Beach Coffee House). In another example, the augmentation system  208  uses the geolocation of the client device  102  to identify a media overlay that includes the name of a merchant at the geolocation of the client device  102 . The media overlay may include other indicia associated with the merchant. The media overlays may be stored in the database  126  and accessed through the database server  120 . 
     In some examples, the augmentation system  208  provides a user-based publication platform that enables users to select a geolocation on a map and upload content associated with the selected geolocation. The user may also specify circumstances under which a particular media overlay should be offered to other users. The augmentation system  208  generates a media overlay that includes the uploaded content and associates the uploaded content with the selected geolocation. 
     In other examples, the augmentation system  208  provides a merchant-based publication platform that enables merchants to select a particular media overlay associated with a geolocation via a bidding process. For example, the augmentation system  208  associates the media overlay of the highest bidding merchant with a corresponding geolocation for a predefined amount of time. The augmentation system  208  communicates with the image processing server  122  to obtain AR experiences and presents identifiers of such experiences in one or more user interfaces (e.g., as icons over a real-time image or video or as thumbnails or icons in interfaces dedicated for presented identifiers of AR experiences). Once an AR experience is selected, one or more images, videos, or AR graphical elements are retrieved and presented as an overlay on top of the images or video captured by the client device  102 . In some cases, the camera is switched to a front-facing view (e.g., the front-facing camera of the client device  102  is activated in response to activation of a particular AR experience) and the images from the front-facing camera of the client device  102  start being displayed on the client device  102  instead of the rear-facing camera of the client device  102 . The one or more images, videos, or AR graphical elements are retrieved and presented as an overlay on top of the images that are captured and displayed by the front-facing camera of the client device  102 . 
     In other examples, the augmentation system  208  is able to communicate and exchange data with another augmentation system  208  on another client device  102  and with the server via the network  112 . The data exchanged can include a session identifier that identifies the shared AR session, a transformation between a first client device  102  and a second client device  102  (e.g., a plurality of client devices  102  include the first and second devices) that is used to align the shared AR session to a common point of origin, a common coordinate frame, functions (e.g., commands to invoke functions), and other payload data (e.g., text, audio, video, or other multimedia data). 
     The augmentation system  208  sends the transformation to the second client device  102  so that the second client device  102  can adjust the AR coordinate system based on the transformation. In this way, the first and second client devices  102  synch up their coordinate systems and frames for displaying content in the AR session. Specifically, the augmentation system  208  computes the point of origin of the second client device  102  in the coordinate system of the first client device  102 . The augmentation system  208  can then determine an offset in the coordinate system of the second client device  102  based on the position of the point of origin from the perspective of the second client device  102  in the coordinate system of the second client device  102 . This offset is used to generate the transformation so that the second client device  102  generates AR content according to a common coordinate system or frame as the first client device  102 . 
     The augmentation system  208  can communicate with the client device  102  to establish individual or shared AR sessions. The augmentation system  208  can also be coupled to the messaging server  118  to establish an electronic group communication session (e.g., group chat, instant messaging) for the client devices  102  in a shared AR session. The electronic group communication session can be associated with a session identifier provided by the client devices  102  to gain access to the electronic group communication session and to the shared AR session. In one example, the client devices  102  first gain access to the electronic group communication session and then obtain the session identifier in the electronic group communication session that allows the client devices  102  to access the shared AR session. In some examples, the client devices  102  are able to access the shared AR session without aid or communication with the augmentation system  208  in the application servers  114 . 
     The map system  210  provides various geographic location functions and supports the presentation of map-based media content and messages by the messaging client  104 . For example, the map system  210  enables the display of user icons or avatars (e.g., stored in profile data  316 ) on a map to indicate a current or past location of “friends” of a user, as well as media content (e.g., collections of messages including photographs and videos) generated by such friends, within the context of a map. For example, a message posted by a user to the messaging system  100  from a specific geographic location may be displayed within the context of a map at that particular location to “friends” of a specific user on a map interface of the messaging client  104 . A user can furthermore share his or her location and status information (e.g., using an appropriate status avatar) with other users of the messaging system  100  via the messaging client  104 , with this location and status information being similarly displayed within the context of a map interface of the messaging client  104  to selected users. 
     The game system  212  provides various gaming functions within the context of the messaging client  104 . The messaging client  104  provides a game interface providing a list of available games (e.g., web-based games or web-based applications) that can be launched by a user within the context of the messaging client  104  and played with other users of the messaging system  100 . The messaging system  100  further enables a particular user to invite other users to participate in the play of a specific game by issuing invitations to such other users from the messaging client  104 . The messaging client  104  also supports both voice and text messaging (e.g., chats) within the context of gameplay, provides a leaderboard for the games, and also supports the provision of in-game rewards (e.g., coins and items). 
     The external resource system  220  provides an interface for the messaging client  104  to communicate with external app(s) servers  110  to launch or access external resources. Each external resource (apps) server  110  hosts, for example, a markup language (e.g., HTML5) based application or small-scale version of an external application (e.g., game, utility, payment, or ride-sharing application that is external to the messaging client  104 ). The messaging client  104  may launch a web-based resource (e.g., application) by accessing the HTML5 file from the external resource (apps) servers  110  associated with the web-based resource. In certain examples, applications hosted by external resource servers  110  are programmed in JavaScript leveraging a Software Development Kit (SDK) provided by the messaging server  118 . The SDK includes APIs with functions that can be called or invoked by the web-based application. In certain examples, the messaging server  118  includes a JavaScript library that provides a given third-party resource access to certain user data of the messaging client  104 . HTML5 is used as an example technology for programming games, but applications and resources programmed based on other technologies can be used. 
     In order to integrate the functions of the SDK into the web-based resource, the SDK is downloaded by an external resource (apps) server  110  from the messaging server  118  or is otherwise received by the external resource (apps) server  110 . Once downloaded or received, the SDK is included as part of the application code of a web-based external resource. The code of the web-based resource can then call or invoke certain functions of the SDK to integrate features of the messaging client  104  into the web-based resource. 
     The SDK stored on the messaging server  118  effectively provides the bridge between an external resource (e.g., third-party or external applications  109  or applets and the messaging client  104 ). This provides the user with a seamless experience of communicating with other users on the messaging client  104 , while also preserving the look and feel of the messaging client  104 . To bridge communications between an external resource and a messaging client  104 , in certain examples, the SDK facilitates communication between external resource servers  110  and the messaging client  104 . In certain examples, a WebViewJavaScriptBridge running on a client device  102  establishes two one-way communication channels between an external resource and the messaging client  104 . Messages are sent between the external resource and the messaging client  104  via these communication channels asynchronously. Each SDK function invocation is sent as a message and callback. Each SDK function is implemented by constructing a unique callback identifier and sending a message with that callback identifier. 
     By using the SDK, not all information from the messaging client  104  is shared with external resource servers  110 . The SDK limits which information is shared based on the needs of the external resource. In certain examples, each external resource server  110  provides an HTML5 file corresponding to the web-based external resource to the messaging server  118 . The messaging server  118  can add a visual representation (such as a box art or other graphic) of the web-based external resource in the messaging client  104 . Once the user selects the visual representation or instructs the messaging client  104  through a graphical user interface of the messaging client  104  to access features of the web-based external resource, the messaging client  104  obtains the HTML5 file and instantiates the resources necessary to access the features of the web-based external resource. 
     The messaging client  104  presents a graphical user interface (e.g., a landing page or title screen) for an external resource. During, before, or after presenting the landing page or title screen, the messaging client  104  determines whether the launched external resource has been previously authorized to access user data of the messaging client  104 . In response to determining that the launched external resource has been previously authorized to access user data of the messaging client  104 , the messaging client  104  presents another graphical user interface of the external resource that includes functions and features of the external resource. In response to determining that the launched external resource has not been previously authorized to access user data of the messaging client  104 , after a threshold period of time (e.g., 3 seconds) of displaying the landing page or title screen of the external resource, the messaging client  104  slides up (e.g., animates a menu as surfacing from a bottom of the screen to a middle of or other portion of the screen) a menu for authorizing the external resource to access the user data. The menu identifies the type of user data that the external resource will be authorized to use. In response to receiving a user selection of an accept option, the messaging client  104  adds the external resource to a list of authorized external resources and allows the external resource to access user data from the messaging client  104 . In some examples, the external resource is authorized by the messaging client  104  to access the user data in accordance with an OAuth 2 framework. 
     The messaging client  104  controls the type of user data that is shared with external resources based on the type of external resource being authorized. For example, external resources that include full-scale external applications (e.g., a third-party or external application  109 ) are provided with access to a first type of user data (e.g., only two-dimensional (2D) avatars of users with or without different avatar characteristics). As another example, external resources that include small-scale versions of external applications (e.g., web-based versions of third-party applications) are provided with access to a second type of user data (e.g., payment information, 2D avatars of users, three-dimensional (3D) avatars of users, and avatars with various avatar characteristics). Avatar characteristics include different ways to customize a look and feel of an avatar, such as different poses, facial features, clothing, and so forth. 
     An AR fashion control system  224  segments a fashion item, such as a shirt, worn by a user depicted in an image (or video) or multiple fashion items worn respectively by multiple users depicted in an image (or video). An illustrative implementation of the AR fashion control system  224  is shown and described in connection with  FIG.  5    below. 
     Specifically, the AR fashion control system  224  is a component that can be accessed by an AR/VR application implemented on the client device  102 . The AR/VR application uses an RGB camera to capture a monocular image of a user and the garment or garments (alternatively referred to as fashion item(s)) worn by the user. The AR/VR application applies various trained machine learning techniques on the captured image of the user wearing the garment to segment the garment (e.g., a shirt, jacket, pants, dress, and so forth) worn by the user in the image and to apply one or more AR visual effects (e.g., game-based AR elements) to the captured image. Segmenting the garment results in an outline of the borders of the garment that appear in the image or video. Pixels within the borders of the segmented garment correspond to the garment or clothing worn by the user. The segmented garment is used to distinguish the clothing or garment worn by the user from other objects or elements depicted in the image, such as parts of the user&#39;s body (e.g., arms, head, legs, and so forth) and the background of the image which can be separately segmented and tracked. In some implementations, the AR/VR application continuously captures images of the user wearing the garment in real time or periodically to continuously or periodically update the applied one or more visual effects. This allows the user to move around in the real world and see the one or more visual effects update in real time. 
     In order for the AR/VR application to apply the one or more visual effects directly from a captured RGB image, the AR/VR application obtains a trained machine learning technique from the AR fashion control system  224 . The trained machine learning technique processes the captured RGB image to generate a segmentation from the captured image that corresponds to the garment worn by the user(s) depicted in the captured RGB image. 
     In training, the AR fashion control system  224  obtains a first plurality of input training images that include depictions of one or more users wearing different garments. These training images also provide the ground truth information about the segmentations of the garments worn by the users depicted in each image. A machine learning technique (e.g., a deep neural network) is trained based on features of the plurality of training images. Specifically, the first machine learning technique extracts one or more features from a given training image and estimates a segmentation of the garment worn by the user depicted in the given training image. The machine learning technique obtains the ground truth information corresponding to the training image and adjusts or updates one or more coefficients or parameters to improve subsequent estimations of segmentations of the garment, such as the shirt. 
     Data Architecture 
       FIG.  3    is a schematic diagram illustrating data structures  300 , which may be stored in the database  126  of the messaging server system  108 , according to certain examples. While the content of the database  126  is shown to comprise a number of tables, it will be appreciated that the data could be stored in other types of data structures (e.g., as an object-oriented database). 
     The database  126  includes message data stored within a message table  302 . This message data includes, for any particular one message, at least message sender data, message recipient (or receiver) data, and a payload. Further details regarding information that may be included in a message, and included within the message data stored in the message table  302 , are described below with reference to  FIG.  4   . 
     An entity table  306  stores entity data, and is linked (e.g., referentially) to an entity graph  308  and profile data  316 . Entities for which records are maintained within the entity table  306  may include individuals, corporate entities, organizations, objects, places, events, and so forth. Regardless of entity type, any entity regarding which the messaging server system  108  stores data may be a recognized entity. Each entity is provided with a unique identifier, as well as an entity type identifier (not shown). 
     The entity graph  308  stores information regarding relationships and associations between entities. Such relationships may be social, professional (e.g., work at a common corporation or organization), interested-based, or activity-based, merely for example. 
     The profile data  316  stores multiple types of profile data about a particular entity. The profile data  316  may be selectively used and presented to other users of the messaging system  100 , based on privacy settings specified by a particular entity. Where the entity is an individual, the profile data  316  includes, for example, a user name, telephone number, address, and settings (e.g., notification and privacy settings), as well as a user-selected avatar representation (or collection of such avatar representations). A particular user may then selectively include one or more of these avatar representations within the content of messages communicated via the messaging system  100  and on map interfaces displayed by messaging clients  104  to other users. The collection of avatar representations may include “status avatars,” which present a graphical representation of a status or activity that the user may select to communicate at a particular time. 
     Where the entity is a group, the profile data  316  for the group may similarly include one or more avatar representations associated with the group, in addition to the group name, members, and various settings (e.g., notifications) for the relevant group. 
     The database  126  also stores augmentation data, such as overlays or filters, in an augmentation table  310 . The augmentation data is associated with and applied to videos (for which data is stored in a video table  304 ) and images (for which data is stored in an image table  312 ). 
     The database  126  can also store data pertaining to individual and shared AR sessions. This data can include data communicated between an AR session client controller of a first client device  102  and another AR session client controller of a second client device  102 , and data communicated between the AR session client controller and the augmentation system  208 . Data can include data used to establish the common coordinate frame of the shared AR scene, the transformation between the devices, the session identifier, images depicting a body, skeletal joint positions, wrist joint positions, feet, and so forth. 
     Filters, in one example, are overlays that are displayed as overlaid on an image or video during presentation to a recipient user. Filters may be of various types, including user-selected filters from a set of filters presented to a sending user by the messaging client  104  when the sending user is composing a message. Other types of filters include geolocation filters (also known as geo-filters), which may be presented to a sending user based on geographic location. For example, geolocation filters specific to a neighborhood or special location may be presented within a user interface by the messaging client  104 , based on geolocation information determined by a Global Positioning System (GPS) unit of the client device  102 . 
     Another type of filter is a data filter, which may be selectively presented to a sending user by the messaging client  104 , based on other inputs or information gathered by the client device  102  during the message creation process. Examples of data filters include current temperature at a specific location, a current speed at which a sending user is traveling, battery life for a client device  102 , or the current time. 
     Other augmentation data that may be stored within the image table  312  includes AR content items (e.g., corresponding to applying AR experiences). An AR content item or AR item may be a real-time special effect and sound that may be added to an image or a video. 
     As described above, augmentation data includes AR content items, overlays, image transformations, AR images, AR logos or emblems, and similar terms that refer to modifications that may be applied to image data (e.g., videos or images). This includes real-time modifications, which modify an image as it is captured using device sensors (e.g., one or multiple cameras) of a client device  102  and then displayed on a screen of the client device  102  with the modifications. This also includes modifications to stored content, such as video clips in a gallery that may be modified. For example, in a client device  102  with access to multiple AR content items, a user can use a single video clip with multiple AR content items to see how the different AR content items will modify the stored clip. For example, multiple AR content items that apply different pseudorandom movement models can be applied to the same content by selecting different AR content items for the content. Similarly, real-time video capture may be used with an illustrated modification to show how video images currently being captured by sensors of a client device  102  would modify the captured data. Such data may simply be displayed on the screen and not stored in memory, or the content captured by the device sensors may be recorded and stored in memory with or without the modifications (or both). In some systems, a preview feature can show how different AR content items will look within different windows in a display at the same time. This can, for example, enable multiple windows with different pseudorandom animations to be viewed on a display at the same time. 
     Data and various systems using AR content items or other such transform systems to modify content using this data can thus involve detection of objects (e.g., faces, hands, bodies, cats, dogs, surfaces, objects, etc.), tracking of such objects as they leave, enter, and move around the field of view in video frames, and the modification or transformation of such objects as they are tracked. In various examples, different methods for achieving such transformations may be used. Some examples may involve generating a 3D mesh model of the object or objects and using transformations and animated textures of the model within the video to achieve the transformation. In other examples, tracking of points on an object may be used to place an image or texture (which may be 2D or 3D) at the tracked position. In still further examples, neural network analysis of video frames may be used to place images, models, or textures in content (e.g., images or frames of video). AR content items thus refer both to the images, models, and textures used to create transformations in content, as well as to additional modeling and analysis information needed to achieve such transformations with object detection, tracking, and placement. 
     Real-time video processing can be performed with any kind of video data (e.g., video streams, video files, etc.) saved in a memory of a computerized system of any kind. For example, a user can load video files and save them in a memory of a device or can generate a video stream using sensors of the device. Additionally, any objects can be processed using a computer animation model, such as a human&#39;s face and parts of a human body, animals, or non-living things such as chairs, cars, or other objects. 
     In some examples, when a particular modification is selected along with content to be transformed, elements to be transformed are identified by the computing device and then detected and tracked if they are present in the frames of the video. The elements of the object are modified according to the request for modification, thus transforming the frames of the video stream. Transformation of frames of a video stream can be performed by different methods for different kinds of transformation. For example, for transformations of frames mostly referring to changing forms of an object&#39;s elements, characteristic points for each element of an object are calculated (e.g., using an Active Shape Model (ASM) or other known methods). Then, a mesh based on the characteristic points is generated for each of the at least one element of the object. This mesh is used in the following stage of tracking the elements of the object in the video stream. In the process of tracking, the mentioned mesh for each element is aligned with a position of each element. Then, additional points are generated on the mesh. A first set of first points is generated for each element based on a request for modification, and a set of second points is generated for each element based on the set of first points and the request for modification. Then, the frames of the video stream can be transformed by modifying the elements of the object on the basis of the sets of first and second points and the mesh. In such method, a background of the modified object can be changed or distorted as well by tracking and modifying the background. 
     In some examples, transformations changing some areas of an object using its elements can be performed by calculating characteristic points for each element of an object and generating a mesh based on the calculated characteristic points. Points are generated on the mesh and then various areas based on the points are generated. The elements of the object are then tracked by aligning the area for each element with a position for each of the at least one elements, and properties of the areas can be modified based on the request for modification, thus transforming the frames of the video stream. Depending on the specific request for modification, properties of the mentioned areas can be transformed in different ways. Such modifications may involve changing color of areas; removing at least some part of areas from the frames of the video stream; including one or more new objects into areas which are based on a request for modification; and modifying or distorting the elements of an area or object. In various examples, any combination of such modifications or other similar modifications may be used. For certain models to be animated, some characteristic points can be selected as control points to be used in determining the entire state-space of options for the model animation. 
     In some examples of a computer animation model to transform image data using face detection, the face is detected on an image with use of a specific face detection algorithm (e.g., Viola-Jones). Then, an ASM algorithm is applied to the face region of an image to detect facial feature reference points. 
     Other methods and algorithms suitable for face detection can be used. For example, in some examples, features are located using a landmark, which represents a distinguishable point present in most of the images under consideration. For facial landmarks, for example, the location of the left eye pupil may be used. If an initial landmark is not identifiable (e.g., if a person has an eyepatch), secondary landmarks may be used. Such landmark identification procedures may be used for any such objects. In some examples, a set of landmarks forms a shape. Shapes can be represented as vectors using the coordinates of the points in the shape. One shape is aligned to another with a similarity transform (allowing translation, scaling, and rotation) that minimizes the average Euclidean distance between shape points. The mean shape is the mean of the aligned training shapes. 
     In some examples, a search is started for landmarks from the mean shape aligned to the position and size of the face determined by a global face detector. Such a search then repeats the steps of suggesting a tentative shape by adjusting the locations of shape points by template matching of the image texture around each point and then conforming the tentative shape to a global shape model until convergence occurs. In some systems, individual template matches are unreliable, and the shape model pools the results of the weak template matches to form a stronger overall classifier. The entire search is repeated at each level in an image pyramid, from coarse to fine resolution. 
     A transformation system can capture an image or video stream on a client device (e.g., the client device  102 ) and perform complex image manipulations locally on the client device  102  while maintaining a suitable user experience, computation time, and power consumption. The complex image manipulations may include size and shape changes, emotion transfers (e.g., changing a face from a frown to a smile), state transfers (e.g., aging a subject, reducing apparent age, changing gender), style transfers, graphical element application, and any other suitable image or video manipulation implemented by a convolutional neural network that has been configured to execute efficiently on the client device  102 . 
     In some examples, a computer animation model to transform image data can be used by a system where a user may capture an image or video stream of the user (e.g., a selfie) using a client device  102  having a neural network operating as part of a messaging client  104  operating on the client device  102 . The transformation system operating within the messaging client  104  determines the presence of a face within the image or video stream and provides modification icons associated with a computer animation model to transform image data, or the computer animation model can be present as associated with an interface described herein. The modification icons include changes that may be the basis for modifying the user&#39;s face within the image or video stream as part of the modification operation. Once a modification icon is selected, the transformation system initiates a process to convert the image of the user to reflect the selected modification icon (e.g., generate a smiling face on the user). A modified image or video stream may be presented in a graphical user interface displayed on the client device  102  as soon as the image or video stream is captured and a specified modification is selected. The transformation system may implement a complex convolutional neural network on a portion of the image or video stream to generate and apply the selected modification. That is, the user may capture the image or video stream and be presented with a modified result in real-time or near real-time once a modification icon has been selected. Further, the modification may be persistent while the video stream is being captured and the selected modification icon remains toggled. Machine-taught neural networks may be used to enable such modifications. 
     The graphical user interface, presenting the modification performed by the transformation system, may supply the user with additional interaction options. Such options may be based on the interface used to initiate the content capture and selection of a particular computer animation model (e.g., initiation from a content creator user interface). In various examples, a modification may be persistent after an initial selection of a modification icon. The user may toggle the modification on or off by tapping or otherwise selecting the face being modified by the transformation system and store it for later viewing or browse to other areas of the imaging application. Where multiple faces are modified by the transformation system, the user may toggle the modification on or off globally by tapping or selecting a single face modified and displayed within a graphical user interface. In some examples, individual faces, among a group of multiple faces, may be individually modified, or such modifications may be individually toggled by tapping or selecting the individual face or a series of individual faces displayed within the graphical user interface. 
     A story table  314  stores data regarding collections of messages and associated image, video, or audio data, which are compiled into a collection (e.g., a story or a gallery). The creation of a particular collection may be initiated by a particular user (e.g., each user for which a record is maintained in the entity table  306 ). A user may create a “personal story” in the form of a collection of content that has been created and sent/broadcast by that user. To this end, the user interface of the messaging client  104  may include an icon that is user-selectable to enable a sending user to add specific content to his or her personal story. 
     A collection may also constitute a “live story,” which is a collection of content from multiple users that is created manually, automatically, or using a combination of manual and automatic techniques. For example, a “live story” may constitute a curated stream of user-submitted content from various locations and events. Users whose client devices have location services enabled and are at a common location event at a particular time may, for example, be presented with an option, via a user interface of the messaging client  104 , to contribute content to a particular live story. The live story may be identified to the user by the messaging client  104 , based on his or her location. The end result is a “live story” told from a community perspective. 
     A further type of content collection is known as a “location story,” which enables a user whose client device  102  is located within a specific geographic location (e.g., on a college or university campus) to contribute to a particular collection. In some examples, a contribution to a location story may require a second degree of authentication to verify that the end user belongs to a specific organization or other entity (e.g., is a student on the university campus). 
     As mentioned above, the video table  304  stores video data that, in one example, is associated with messages for which records are maintained within the message table  302 . Similarly, the image table  312  stores image data associated with messages for which message data is stored in the entity table  306 . The entity table  306  may associate various augmentations from the augmentation table  310  with various images and videos stored in the image table  312  and the video table  304 . 
     Trained machine learning technique(s)  307  stores parameters that have been trained during training of the AR fashion control system  224 . For example, trained machine learning techniques  307  stores the trained parameters of one or more neural network machine learning techniques. 
     Segmentation training images  309  stores a plurality of images that each depict one or more users wearing different garments. The plurality of images stored in the segmentation training images  309  includes various depictions of one or more users wearing different garments together with segmentations of the garments that indicate which pixels in the images correspond to the garments and which pixels correspond to a background or a user&#39;s body parts in the images. Namely the segmentations provide the borders of the garments depicted in the images. These segmentation training images  309  are used by the AR fashion control system  224  to train the machine learning technique used to generate a segmentation of one or more garments depicted in a received RGB monocular image. In some cases, the segmentation training images  309  include ground truth skeletal key points of one or more bodies depicted in the respective training monocular images to enhance segmentation performance on various distinguishing attributes (e.g., shoulder straps, collar or sleeves) of the garments. In some cases, the segmentation training images  309  include a plurality of image resolutions of bodies depicted in the images. The segmentation training images  309  can include labeled and unlabeled image and video data. The segmentation training images  309  can include a depiction of a whole body of a particular user, an image that lacks a depiction of any user (e.g., a negative image), a depiction of a plurality of users wearing different garments, and depictions of users wearing garments at different distances from an image capture device. 
     Segmentation training images  309  can also store training image portions depicting different orientations of fashion items and corresponding ground-truth pixel directions of the fashion items (including different types of fashion items) relative to surface normals of cameras used to capture the training image portions. Segmentation training images  309  can also store training image portions depicting reflections of light from different directions on fashion items (including different types of fashion items) and corresponding ground-truth pixel directions of the fashion items relative to surface normals of cameras used to capture the training image portions. Segmentation training images  309  can also store training image portions depicting focusing of light on fashion items (including different types of fashion items) from different directions and corresponding ground-truth lighting conditions of pixels of the fashion items 
     Data Communications Architecture 
       FIG.  4    is a schematic diagram illustrating a structure of a message  400 , according to some examples, generated by a messaging client  104  for communication to a further messaging client  104  or the messaging server  118 . The content of a particular message  400  is used to populate the message table  302  stored within the database  126 , accessible by the messaging server  118 . Similarly, the content of a message  400  is stored in memory as “in-transit” or “in-flight” data of the client device  102  or the application servers  114 . A message  400  is shown to include the following example components:
         message identifier  402 : a unique identifier that identifies the message  400 .   message text payload  404 : text, to be generated by a user via a user interface of the client device  102 , and that is included in the message  400 .   message image payload  406 : image data, captured by a camera component of a client device  102  or retrieved from a memory component of a client device  102 , and that is included in the message  400 . Image data for a sent or received message  400  may be stored in the image table  312 .   message video payload  408 : video data, captured by a camera component or retrieved from a memory component of the client device  102 , and that is included in the message  400 . Video data for a sent or received message  400  may be stored in the video table  304 .   message audio payload  410 : audio data, captured by a microphone or retrieved from a memory component of the client device  102 , and that is included in the message  400 .   message augmentation data  412 : augmentation data (e.g., filters, stickers, or other annotations or enhancements) that represents augmentations to be applied to message image payload  406 , message video payload  408 , or message audio payload  410  of the message  400 . Augmentation data for a sent or received message  400  may be stored in the augmentation table  310 .   message duration parameter  414 : parameter value indicating, in seconds, the amount of time for which content of the message (e.g., the message image payload  406 , message video payload  408 , message audio payload  410 ) is to be presented or made accessible to a user via the messaging client  104 .   message geolocation parameter  416 : geolocation data (e.g., latitudinal and longitudinal coordinates) associated with the content payload of the message. Multiple message geolocation parameter  416  values may be included in the payload, each of these parameter values being associated with respect to content items included in the content (e.g., a specific image within the message image payload  406 , or a specific video in the message video payload  408 ).   message story identifier  418 : identifier values identifying one or more content collections (e.g., “stories” identified in the story table  314 ) with which a particular content item in the message image payload  406  of the message  400  is associated. For example, multiple images within the message image payload  406  may each be associated with multiple content collections using identifier values.   message tag  420 : each message  400  may be tagged with multiple tags, each of which is indicative of the subject matter of content included in the message payload. For example, where a particular image included in the message image payload  406  depicts an animal (e.g., a lion), a tag value may be included within the message tag  420  that is indicative of the relevant animal. Tag values may be generated manually, based on user input, or may be automatically generated using, for example, image recognition.   message sender identifier  422 : an identifier (e.g., a messaging system identifier, email address, or device identifier) indicative of a user of the client device  102  on which the message  400  was generated and from which the message  400  was sent.   message receiver identifier  424 : an identifier (e.g., a messaging system identifier, email address, or device identifier) indicative of a user of the client device  102  to which the message  400  is addressed.       

     The contents (e.g., values) of the various components of message  400  may be pointers to locations in tables within which content data values are stored. For example, an image value in the message image payload  406  may be a pointer to (or address of) a location within an image table  312 . Similarly, values within the message video payload  408  may point to data stored within a video table  304 , values stored within the message augmentation data  412  may point to data stored in an augmentation table  310 , values stored within the message story identifier  418  may point to data stored in a story table  314 , and values stored within the message sender identifier  422  and the message receiver identifier  424  may point to user records stored within an entity table  306 . 
     AR Fashion Control System 
       FIG.  5    is a block diagram showing an example AR fashion control system  224 , according to example examples. AR fashion control system  224  includes a set of components  510  that operate on a set of input data (e.g., a monocular image  501  depicting a real body of a user wearing a shirt and upper segmentation training image data  502 ). The set of input data is obtained from segmentation training images  309  stored in database(s) ( FIG.  3   ) during the training phases and is obtained from an RGB camera of a client device  102  when an AR/VR application is being used, such as by a messaging client  104 . AR fashion control system  224  includes a machine learning technique module  512 , a skeletal key-points module  511 , an upper garment segmentation module  514 , a pixel angle estimation module  517 , an image modification module  518 , an AR effect module  519 , a 3D body tracking module  513 , a whole-body segmentation module  515 , and an image display module  520 . 
     During training, the AR fashion control system  224  receives a given training image or video (e.g., monocular image  501  depicting a real body of a user wearing a garment, such as an image of a user wearing as a shirt (short sleeve, t-shirt, or long sleeve), jacket, tank top, sweater, and so forth, a lower body garment, such as pants or a skirt, a whole body garment, such as a dress or overcoat, or any suitable combination thereof or depicting multiple users simultaneously wearing respective combinations of upper body garments, lower body garments, or whole body garments from segmentation training image data  502 . The AR fashion control system  224  applies one or more machine learning techniques using the machine learning technique module  512  on the given training image or video. The machine learning technique module  512  extracts one or more features from the given training image or video to estimate a segmentation of the garment(s) worn by the user(s) depicted in the image. For example, the machine learning technique module  512  obtains the given training image or video depicting a user wearing a shirt. The machine learning technique module  512  extracts features from the image and segments or specifies which pixels in the image correspond to the shirt worn by the user and which pixels correspond to a background or correspond to parts of the user&#39;s body. Namely, the segmentation output by the machine learning technique module  512  identifies borders of a garment (e.g., the shirt) worn by the user in the given training image. 
     The machine learning technique module  512  retrieves garment segmentation information associated with the given training image or video. The machine learning technique module  512  compares the estimated segmentation (that can include an identification of multiple garments worn by respective users in the image in case there exist multiple users in the image) with the ground truth garment segmentation provided as part of the segmentation training image data  502 . Based on a difference threshold or deviation of the comparison, the machine learning technique module  512  updates one or more coefficients or parameters and obtains one or more additional segmentation training images or videos. After a specified number of epochs or batches of training images have been processed and/or when the difference threshold or deviation reaches a specified value, the machine learning technique module  512  completes training and the parameters and coefficients of the machine learning technique module  512  are stored in the trained machine learning technique(s)  307 . 
     In some examples, the machine learning technique module  512  implements multiple segmentation models of the machine learning technique. Each segmentation model of the machine learning technique module  512  may be trained on a different set of training images associated with a specific resolution. Namely, one of the segmentation models can be trained to estimate a garment segmentation for images having a first resolution (or a first range of resolutions). A second of the segmentation models can be trained to estimate a garment segmentation for images having a second resolution (or a second range of resolutions different from the first range of resolutions). In this way, different complexities of the machine learning technique module  512  can be trained and stored. When a given device having certain capabilities uses the AR/VR application, a corresponding one of the various garment segmentation models can be provided to perform the garment segmentation that matches the capabilities of the given device. In some cases, multiple garment segmentation models of each of the machine leaning techniques implemented by the AR fashion control system  224  can be provided, with each configured to operate with a different level of complexity. The appropriate segmentation model(s) with the appropriate level of complexity can then be provided to a client device  102  for segmenting garments depicted in one or more images. 
     In some examples, during training, the machine learning technique module  512  receives 2D skeletal joint information from a skeletal key-points module  511 . The skeletal key-points module  511  tracks skeletal key points of a user depicted in a given training image (e.g., head joint, shoulder joints, hip joints, leg joints, and so forth) and provides the 2D or 3D coordinates of the skeletal key points. This information is used by the machine learning technique module  512  to identify distinguishing attributes of the garment depicted in the training image. 
     The garment segmentation generated by the machine learning technique module  512  is provided to the upper garment segmentation module  514 . The upper garment segmentation module  514  can determine that the elbow joint output by the skeletal key-points module  511  is at a position that is within a threshold distance away from a given edge of the border of the shirt garment segmentation. In response, the upper garment segmentation module  514  can determine that the garment corresponds to a t-shirt or short sleeve shirt and that the given edge corresponds to a sleeve of the shirt. In such circumstances, the upper garment segmentation module  514  can adjust weights of the parameters or the loss function used to update parameters of the machine learning technique module  512  to improve segmentation of upper body garments, such as shirts. More specifically, the upper garment segmentation module  514  can determine that a given distinguishing attribute is present in the garment segmentation that is generated based on a comparison of skeletal joint positions to borders of the garment segmentation. In such circumstances, the upper garment segmentation module  514  adjusts the loss function or weights used to update the parameters of the machine learning technique module  512  for the training image depicting the garment with the distinguishing attribute. Similarly, the upper garment segmentation module  514  can adjust the loss or the parameter weights based on a difference between the garment segmentation and the pixels corresponding to the background of the image. 
     The upper garment segmentation module  514  is used to track a 2D or 3D position of the segmented shirt in subsequent frames of a video. This enables one or more AR elements to be displayed on the shirt and be maintained at their respective positions on the shirt as the position of the shirt moves around the screen. In this way, the upper garment segmentation module  514  can determine and track which portions of the shirt are currently shown in the image that depicts the user and to selectively adjust the corresponding AR elements that are displayed. For example, a given AR element can be displayed on a left sleeve of the shirt in a first frame of the video. The upper garment segmentation module  514  can determine that the user has turned left in a second frame of the video, meaning that the left sleeve no longer appears in the second frame. In response, the upper garment segmentation module  514  can omit entirely or a portion of the given AR element that was displayed on the left sleeve of the shirt. 
     After training, AR fashion control system  224  receives an input image  501  (e.g., monocular image depicting a user wearing a garment or multiple users wearing respective garments) as a single RGB image from a client device  102 . The AR fashion control system  224  applies the trained machine learning technique module  512  to the received input image  501  to extract one or more features of the image to generate a segmentation of the garment or garments depicted in the image  501 . This segmentation is provided to the upper garment segmentation module  514  to track the 2D or 3D position of the shirt (upper garment) in the current frame of the video and in subsequent frames. 
       FIG.  6    is a diagrammatic representation of outputs of the AR fashion control system  224 , in accordance with some examples. Specifically,  FIG.  6    shows a garment segmentation  600  generated by the upper garment segmentation module  514 . In one example, the upper garment segmentation module  514  generates a first garment segmentation  612  representing pixel locations of a shirt (upper garment) worn by a user. In another example, the upper garment segmentation module  514  generates a second garment segmentation representing pixel locations of a short sleeve shirt (upper garment) worn by a user. In another example, the upper garment segmentation module  514  generates a third garment segmentation representing pixel locations of a jacket (upper garment) worn by a user. 
     The upper garment segmentation module  514  applies the segmentation of the upper garment (or any other garment worn by a person depicted in an image or video) to the image or video. The upper garment segmentation module  514  can extract or cut out that portion of the image or video that corresponds to the upper garment segmentation. For example, the upper garment segmentation module  514  can generate an image portion that only includes the fashion item worn by the person depicted in the image or video corresponding to the upper garment segmentation. While the disclosed techniques are discussed in relation to an upper garment, any other garment segmentation can be generated and used in similar ways. The image portion that depicts the upper garment is provided to the pixel angle estimation module  517 . 
     The pixel angle estimation module  517  is trained to generate values indicating the pixel direction or angle relative to a camera used to capture the image or video depicting the image portion corresponding to the fashion item worn by the person or user depicted in the image. The angle to the camera can in some cases be represented as a normal vector or normal direction of a given pixel. For example, the pixel angle estimation module  517  can determine, for a given pixel, the direction to which the pixel points relative to a surface normal of a camera that captures the image that includes the pixel. This direction can be associated with the pixel by storing the direction in a vector that includes or defines an x, y, z component in a red, green and blue (RGB) channel of each pixel. This can be referred to as the normal map. Namely, each pixel can be represented by an RGB channel that defines the amount of red, green and blue color to associate with the pixel, such as the red, green and blue pixel values for each pixel. This RGB channel can also be associated with a vector that defines the pixel or normal direction of each pixel in the x, y, z coordinate or UV space. In this way, each pixel can include red, green and blue values as well as x, y and z coordinates. 
     As an example, if the pixel is on a left shirt sleeve and the person wearing the shirt is turned left relative to the camera, the pixel angle can be 45 degrees or −45 degrees (or any other suitable angle even an angle that is not facing from the camera) relative to a surface normal of the camera. A larger pixel angle indicates that the portion of the fashion item represented by the corresponding pixel is turned further right/left relative to the camera. The pixel angle can be one-dimensional and/or 2D. In case of being 2D, the pixel angle represents how much the fashion item is turned left/right relative to the camera and also how far up/down the portion of the fashion item is pointing. The pixel angle estimation module  517  generates a matrix representing the one-dimensional, 2D pixel angle, and/or 3D pixel angle for each pixel in the portion of the image corresponding to the fashion item or garment segmentation. The pixel angle can be represented by a 3D normal vector or 2D normal vector and stored in the RGB channel of each pixel. In some cases, the pixel angle estimation module  517  generates the values discussed in this disclosure independently from movement or tracking information provided by the 3D body tracking module  513 . 
     In some examples, the pixel angle estimation module  517  implements a neural network. The neural network can process a portion of an image corresponding to the fashion item to estimate the angle of each pixel relative to the surface normal of the camera used to capture the image or video. The neural network can be trained to establish a relationship between image portions depicting different orientations of fashion items and pixel directions of the fashion items relative to surface normals of cameras used to capture the image portions. Namely, during training, the pixel angle estimation module  517  receives a given training image or video (e.g., image portion depicting a real body of a user wearing a garment, such as an image of a user wearing as a shirt (short sleeve, t-shirt, or long sleeve), jacket, tank top, sweater, and so forth, a lower body garment, such as pants or a skirt, a whole body garment, such as a dress or overcoat, or any suitable combination thereof or depicting multiple users simultaneously wearing respective combinations of upper body garments, lower body garments or whole body garments) from segmentation training image data  502 . The pixel angle estimation module  517  applies one or more machine learning techniques on the given training image or video. The pixel angle estimation module  517  extracts one or more features from the given training image or video to estimate the angle of each pixel relative to the surface normal of the camera used to capture the image or video. For example, the pixel angle estimation module  517  can generate a matrix representing the one-dimensional or 2D pixel angle for each pixel in the portion of the image that is processed. 
     The pixel angle estimation module  517  retrieves ground-truth pixel angle information (e.g., ground-truth matrix data representing the angle of each pixel in the image portion) associated with the given training image or video. The pixel angle estimation module  517  compares the estimated angles of each pixel with the ground truth pixel angle information provided as part of the segmentation training image data  502 . Based on a difference threshold or deviation of the comparison, the pixel angle estimation module  517  updates one or more coefficients or parameters and obtains one or more additional segmentation training images or videos. After a specified number of epochs or batches of training images have been processed and/or when the difference threshold or deviation reaches a specified value, the pixel angle estimation module  517  completes training and the parameters and coefficients of the pixel angle estimation module  517  are stored in the trained machine learning technique(s)  307 . 
     As another example, the neural network can be trained to establish a relationship between image portions depicting reflections of light from different directions on fashion items and pixel directions of the fashion items relative to surface normals of cameras used to capture the image portions. In such cases, during training, the pixel angle estimation module  517  receives a given training image or video (e.g., image portions depicting reflections/absorptions of light from different directions on fashion items) from segmentation training image data  502 . The pixel angle estimation module  517  applies one or more machine learning techniques on the given training image or video. The pixel angle estimation module  517  extracts one or more features from the given training image or video to estimate the angle of each pixel relative to the surface normal of the camera used to capture the image or video. For example, the pixel angle estimation module  517  can generate a matrix representing the one-dimensional or 2D pixel angle for each pixel in the portion of the image that is processed. 
     The pixel angle estimation module  517  retrieves ground-truth pixel angle information (e.g., ground-truth matrix data representing the angle of each pixel in the image portion) associated with the given training image or video. The pixel angle estimation module  517  compares the estimated angles of each pixel with the ground truth pixel angle information provided as part of the segmentation training image data  502 . Based on a difference threshold or deviation of the comparison, the pixel angle estimation module  517  updates one or more coefficients or parameters and obtains one or more additional segmentation training images or videos. After a specified number of epochs or batches of training images have been processed and/or when the difference threshold or deviation reaches a specified value, the pixel angle estimation module  517  completes training and the parameters and coefficients of the pixel angle estimation module  517  are stored in the trained machine learning technique(s)  307 . 
     As another example, the neural network can be trained to estimate lighting conditions for each pixel in the portion when the AR light is applied from a new direction (a direction specified in input received from a user). In such cases, the neural network is trained to establish a relationship between image portions depicting focusing of light on fashion items from different directions and lighting conditions of pixels of the fashion items. Namely, during training, the pixel angle estimation module  517  receives a given training image or video (e.g., image portions depicting reflections of light from different directions and lighting conditions on fashion items) from segmentation training image data  502 . The pixel angle estimation module  517  applies one or more machine learning techniques on the given training image or video. The pixel angle estimation module  517  extracts one or more features from the given training image or video to estimate the focusing of light on fashion items from new directions and lighting conditions of pixels of the fashion items. Specifically, the pixel angle estimation module  517  receives a given training image or video depicting reflections of light from a first direction and first lighting conditions on fashion items. The pixel angle estimation module  517  applies one or more machine learning techniques on the given training image or video. The pixel angle estimation module  517  extracts one or more features from the given training image or video to estimate the focusing of light on fashion items from a second direction and second lighting conditions of pixels of the fashion items. 
     The pixel angle estimation module  517  retrieves ground-truth pixel lighting conditions for the new direction associated with the given training image or video. The pixel angle estimation module  517  compares the estimated lighting conditions of each pixel with the ground truth pixel lighting conditions provided as part of the segmentation training image data  502 . Based on a difference threshold or deviation of the comparison, the pixel angle estimation module  517  updates one or more coefficients or parameters and obtains one or more additional segmentation training images or videos. After a specified number of epochs or batches of training images have been processed and/or when the difference threshold or deviation reaches a specified value, the pixel angle estimation module  517  completes training and the parameters and coefficients of the pixel angle estimation module  517  are stored in the trained machine learning technique(s)  307 . 
     In some cases, the pixel angle estimation module  517  is trained to determine reflection and/or absorption of light for different material properties of fashion items. In such cases, the pixel angle estimation module  517  implements a neural network that establishes a relationship between material properties of fashion items and reflection and/or absorption amounts and/or pixel angles relative to a camera surface normal used to capture an image depicting the fashion item. The pixel angle estimation module  517  is trained to process various types of fashion item materials (e.g., gold, water, mirror, and so forth) to estimate the reflection and/or absorption amounts and/or pixel angles relative to a camera surface normal used to capture an image depicting the fashion item. The estimated reflection and/or absorption amounts and/or pixel angles relative to a camera surface normal used to capture an image depicting the fashion item are compared with ground-truth information to update parameters of the pixel angle estimation module  517 . 
     After being trained, the pixel angle estimation module  517  can compute or estimate pixel angles and/or lighting conditions for pixels of a portion of an image corresponding to a fashion item in real time. The pixel angle estimation module  517  can continuously or periodically update the pixel angles and/or lighting conditions as the fashion item moves around a video. The pixel angles and/or lighting conditions provided by the pixel angle estimation module  517  are used by the AR effect module  519  to update the pixel values of the portion of the image corresponding to the fashion item to represent reflection and/or absorption of light from different angles and for different materials. In some cases, the AR effect module  519  updates the pixel values independently from movement information provided by the 3D body tracking module  513 . 
     A user of the AR/VR application may be presented with an option to select an AR application or experience to control display of AR elements on a shirt worn by the user, such as to change a material of the shirt or fashion item or re-focus light from a different direction (e.g., to apply artificial or AR light to the fashion item). In response to receiving a user selection of the option, a camera (e.g., front-facing or rear-facing camera) is activated to begin capturing an image or video of the user wearing a shirt (or upper garment or fashion item). The image or video depicting the user wearing the shirt (or upper garment or fashion item) is provided to the AR effect module  519  to apply one or more AR elements to the shirt or to change the pixel values of the shirt to represent a different material or light being focused from a different direction. The AR effect module  519  selects between various applications/modifications of AR elements displayed on the shirt (or upper garment or fashion item) worn by the user, such as based on gestures or movement of the user detected by the 3D body tracking module  513  and/or whole-body segmentation module  515 .  FIGS.  7  and  8    show illustrative outputs of one or more of the visual effects that can be selected and applied by the AR effect module  519 . 
     For example, the AR effect module  519  can determine that light is being focused on the fashion item (shirt or upper garment) from a first direction based on the estimated angle of each pixel. In response, the AR effect module  519  can modify pixel values of the portion of the fashion item to re-focus the light on the fashion item from a second direction based on the estimated angle of each pixel. Specifically, the AR effect module  519  can determine that a first pixel in the portion of the image is pointing towards a given direction relative to the camera or surface normal of the camera. In such cases, the AR effect module  519  can modify the first pixel to render a reflection of the re-focused light from the second direction towards the given direction. 
     As another example, the AR effect module  519  can select or receive a selection of an AR material for the fashion item and can replace a material of the fashion item with the AR material based on the estimated angle of each pixel. The AR effect module  519  can display a list of different AR materials and can receive a selection of the AR material from the list. The selection can be made verbally using speech input from the user or by receiving touch input from the user touching a particular one of the AR materials in the list. 
     The AR effect module  519  can determine a light reflection or absorption property of the AR material. In response, the AR effect module  519  can, for each pixel in the portion of the image, compute a new pixel value based on the light reflection or absorption property of the AR material and the estimated angle of the pixel. In this way, the AR effect module  519  can apply different AR shades to the fashion item depicted in the image or video for each different type of the AR material that is selected. In one example, the fashion item worn by the person depicted in the image or video can be made of a cloth or cloth-like material and the AR effect module  519  can replace the cloth or cloth-like material with an AR material, such as gold, mirror, metal, water, or slime. In such cases, the light reflection and/or absorption properties of the fashion item worn by the person depicted in the image or video is changed to correspond to the light reflection and/or absorption properties of the AR material. To perform such AR changes, the AR effect module  519  can modify each pixel value of the portion of the image that corresponds to the fashion item based on the estimated angle of the corresponding pixel relative to the camera. The value of the pixel of the portion of the fashion item represents the direction at which light is reflected or absorbed by that portion of the fashion item made of the AR material and differs from the direction at which light is reflected or absorbed that portion of the fashion item made by the cloth or cloth-like material. 
     The image modification module  518  can adjust the image captured by the camera based on the game-based AR effect selected by the AR effect module  519 . The image modification module  518  adjusts the way in which the garment(s) worn by the user is/are presented in an image or video, such as by changing the color or occlusion pattern of the garment worn by the user based on the garment segmentation and applying one or more AR elements to the fashion item worn by the user depicted in the image or video. Image display module  520  combines the adjustments made by the image modification module  518  into the received monocular image or video depicting the user&#39;s body. The image or video is provided by the image display module  520  to the client device  102  and can then be sent to another user or stored for later access and display. 
     In some examples, the image modification module  518  receives 3D body tracking information representing the 3D positions of the user depicted in the image from the 3D body tracking module  513 . The 3D body tracking module  513  generates the 3D body tracking information by processing the image  501  using additional machine learning techniques. The image modification module  518  can also receive a whole-body segmentation representing which pixels in the image correspond to the whole body of the user from another machine learning technique. The whole-body segmentation can be received from the whole-body segmentation module  515 . The whole-body segmentation module  515  generates the whole-body segmentation by processing the image  501  using a machine learning technique. 
     The image modification module  518  can control the display of virtual or AR elements based on the garment segmentation provided by the upper garment segmentation module  514  and based on the 3D body tracking positions of the user and the whole-body segmentation of the user. 
     In one example, as shown in  FIG.  7   , the AR effect module  519  can apply one or more AR effects  730  to a shirt  710  worn by a user  720  depicted in an image  700  captured by a client device  102 . The one or more AR effects  730  can include an AR game board, an AR gaming controller for controlling a gaming application interface, an AR ball game, an AR capture game, an AR flying saucer game, or any other type of AR gaming experience that can be displayed on a fashion item of a user and interacted by gestures performed by the user. Other types of AR effects  730  can include AR music related AR elements (discussed above), AR avatars, AR voice transcriptions, AR elements that are based on voice expressions of the use  720 , and the like. Other types of AR effects  730  can represent different material properties of the shirt  710  (e.g., replacing the shirt from being made of cloth to being made of gold, water or slime). Other types of AR effects  730  can represent different lighting conditions on the shirt  710 , such as refocusing light from coming from the top using artificial or AR light coming from the bottom of the image. In such cases, the light reflection and/or absorption on the shirt  710  changes and is represented by modifying the pixel values of the shirt  710 , such as based on their respective pixel angle relative to the camera used to capture the image of the shirt  710 . 
     As another example shown in  FIG.  8   , the AR effect module  519  can generate replace material properties of the shirt  810  (or fashion item) worn by the person or user  826  depicted in the image  800  or video. The AR effect module  519  can select a new material property for the fashion item associated with an AR experience. In some cases, the AR effect module  519  can receive a request to replace the material of a first fashion item (e.g., the shirt  810 ) with a first material type (e.g., gold) and can receive a request to replace the material of a second fashion item (e.g., pants or certain portion of the shirt  810 ) with a second material type (e.g., water). Pixel values of the fashion item or fashion items are modified to represent reflections and/or absorptions of light based on the pixel angles of each fashion item and based on the properties of the selected material type (e.g., water can be more absorptive of light than gold). 
     The pixel values are further modified based on tracking movement of the person depicted in the image  800  or video. For example, the shirt  810  can be moved around in the video based on movement of the user  826  and changes to the light reflection and/or absorption of the pixels is updated based on newly computed pixel angle estimations provided by the pixel angle estimation module  517 . The pixel values are modified to represent the new angles that result based on movement of the user  826  and to preserve the lighting conditions resulting from the direction from which real or AR light is focused on the fashion item and/or the AR material properties of the corresponding fashion item. The AR effect module  519  can rotate the AR elements based on rotations of the user  826  to represent differences in lighting conditions (e.g., differences in light reflections and/or absorptions) on the fashion item as the pixel angles change when the user  826  rotates. This makes it appear as though the AR lighting and/or AR materials of the shirt  810  are part of the real-world world. 
       FIG.  9    is a flowchart of a process  900  performed by the AR fashion control system  224 , in accordance with some example examples. Although the flowchart can describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed. A process may correspond to a method, a procedure, and the like. The steps of methods may be performed in whole or in part, may be performed in conjunction with some or all of the steps in other methods, and may be performed by any number of different systems or any portion thereof, such as a processor included in any of the systems. 
     At operation  901 , the AR fashion control system  224  (e.g., a client device  102  or a server) receives an image that includes a depiction of a person wearing a fashion item, as discussed above. 
     At operation  902 , the AR fashion control system  224  generates a segmentation of the fashion item worn by the person depicted in the image, as discussed above. 
     At operation  903 , the AR fashion control system  224  extracts a portion of the image corresponding to the segmentation of the fashion item, as discussed above. 
     At operation  904 , the AR fashion control system  224  estimates an angle of each pixel in the portion of the image relative to a camera used to capture the image, as discussed above. 
     At operation  905 , the AR fashion control system  224  applies one or more AR elements to the fashion item in the image based on the estimated angle of each pixel in the portion of the image relative to the camera used to capture the image, as discussed above. 
     Machine Architecture 
       FIG.  10    is a diagrammatic representation of the machine  1000  within which instructions  1008  (e.g., software, a program, an application, an applet, an app, or other executable code) for causing the machine  1000  to perform any one or more of the methodologies discussed herein may be executed. For example, the instructions  1008  may cause the machine  1000  to execute any one or more of the methods described herein. The instructions  1008  transform the general, non-programmed machine  1000  into a particular machine  1000  programmed to carry out the described and illustrated functions in the manner described. The machine  1000  may operate as a standalone device or may be coupled (e.g., networked) to other machines. In a networked deployment, the machine  1000  may operate in the capacity of a server machine or a client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine  1000  may comprise, but not be limited to, a server computer, a client computer, a personal computer (PC), a tablet computer, a laptop computer, a netbook, a set-top box (STB), a personal digital assistant (PDA), an entertainment media system, a cellular telephone, a smartphone, a mobile device, a wearable device (e.g., a smartwatch), a smart home device (e.g., a smart appliance), other smart devices, a web appliance, a network router, a network switch, a network bridge, or any machine capable of executing the instructions  1008 , sequentially or otherwise, that specify actions to be taken by the machine  1000 . Further, while only a single machine  1000  is illustrated, the term “machine” shall also be taken to include a collection of machines that individually or jointly execute the instructions  1008  to perform any one or more of the methodologies discussed herein. The machine  1000 , for example, may comprise the client device  102  or any one of a number of server devices forming part of the messaging server system  108 . In some examples, the machine  1000  may also comprise both client and server systems, with certain operations of a particular method or algorithm being performed on the server-side and with certain operations of the particular method or algorithm being performed on the client-side. 
     The machine  1000  may include processors  1002 , memory  1004 , and input/output (I/O) components  1038 , which may be configured to communicate with each other via a bus  1040 . In an example, the processors  1002  (e.g., a Central Processing Unit (CPU), a Reduced Instruction Set Computing (RISC) Processor, a Complex Instruction Set Computing (CISC) Processor, a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Radio-Frequency Integrated Circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor  1006  and a processor  1010  that execute the instructions  1008 . The term “processor” is intended to include multi-core processors that may comprise two or more independent processors (sometimes referred to as “cores”) that may execute instructions contemporaneously. Although  FIG.  10    shows multiple processors  1002 , the machine  1000  may include a single processor with a single-core, a single processor with multiple cores (e.g., a multi-core processor), multiple processors with a single core, multiple processors with multiples cores, or any combination thereof. 
     The memory  1004  includes a main memory  1012 , a static memory  1014 , and a storage unit  1016 , all accessible to the processors  1002  via the bus  1040 . The main memory  1004 , the static memory  1014 , and the storage unit  1016  store the instructions  1008  embodying any one or more of the methodologies or functions described herein. The instructions  1008  may also reside, completely or partially, within the main memory  1012 , within the static memory  1014 , within machine-readable medium  1018  within the storage unit  1016 , within at least one of the processors  1002  (e.g., within the processor&#39;s cache memory), or any suitable combination thereof, during execution thereof by the machine  1000 . 
     The I/O components  1038  may include a wide variety of components to receive input, provide output, produce output, transmit information, exchange information, capture measurements, and so on. The specific I/O components  1038  that are included in a particular machine will depend on the type of machine. For example, portable machines such as mobile phones may include a touch input device or other such input mechanisms, while a headless server machine will likely not include such a touch input device. It will be appreciated that the I/O components  1038  may include many other components that are not shown in  FIG.  10   . In various examples, the I/O components  1038  may include user output components  1024  and user input components  1026 . The user output components  1024  may include visual components (e.g., a display such as a plasma display panel (PDP), a light-emitting diode (LED) display, a liquid crystal display (LCD), a projector, or a cathode ray tube (CRT)), acoustic components (e.g., speakers), haptic components (e.g., a vibratory motor, resistance mechanisms), other signal generators, and so forth. The user input components  1026  may include alphanumeric input components (e.g., a keyboard, a touch screen configured to receive alphanumeric input, a photo-optical keyboard, or other alphanumeric input components), point-based input components (e.g., a mouse, a touchpad, a trackball, a joystick, a motion sensor, or another pointing instrument), tactile input components (e.g., a physical button, a touch screen that provides location and force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like. 
     In further examples, the I/O components  1038  may include biometric components  1028 , motion components  1030 , environmental components  1032 , or position components  1034 , among a wide array of other components. For example, the biometric components  1028  include components to detect expressions (e.g., hand expressions, facial expressions, vocal expressions, body gestures, or eye-tracking), measure biosignals (e.g., blood pressure, heart rate, body temperature, perspiration, or brain waves), identify a person (e.g., voice identification, retinal identification, facial identification, fingerprint identification, or electroencephalogram-based identification), and the like. The motion components  1030  include acceleration sensor components (e.g., accelerometer), gravitation sensor components, and rotation sensor components (e.g., gyroscope). 
     The environmental components  1032  include, for example, one or more cameras (with still image/photograph and video capabilities), illumination sensor components (e.g., photometer), temperature sensor components (e.g., one or more thermometers that detect ambient temperature), humidity sensor components, pressure sensor components (e.g., barometer), acoustic sensor components (e.g., one or more microphones that detect background noise), proximity sensor components (e.g., infrared sensors that detect nearby objects), gas sensors (e.g., gas detection sensors to detection concentrations of hazardous gases for safety or to measure pollutants in the atmosphere), or other components that may provide indications, measurements, or signals corresponding to a surrounding physical environment. 
     With respect to cameras, the client device  102  may have a camera system comprising, for example, front cameras on a front surface of the client device  102  and rear cameras on a rear surface of the client device  102 . The front cameras may, for example, be used to capture still images and video of a user of the client device  102  (e.g., “selfies”), which may then be augmented with augmentation data (e.g., filters) described above. The rear cameras may, for example, be used to capture still images and videos in a more traditional camera mode, with these images similarly being augmented with augmentation data. In addition to front and rear cameras, the client device  102  may also include a 360° camera for capturing 360° photographs and videos. 
     Further, the camera system of a client device  102  may include dual rear cameras (e.g., a primary camera as well as a depth-sensing camera), or even triple, quad, or penta rear camera configurations on the front and rear sides of the client device  102 . These multiple cameras systems may include a wide camera, an ultra-wide camera, a telephoto camera, a macro camera, and a depth sensor, for example. 
     The position components  1034  include location sensor components (e.g., a GPS receiver component), altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude may be derived), orientation sensor components (e.g., magnetometers), and the like. 
     Communication may be implemented using a wide variety of technologies. The I/O components  1038  further include communication components  1036  operable to couple the machine  1000  to a network  1020  or devices  1022  via respective coupling or connections. For example, the communication components  1036  may include a network interface component or another suitable device to interface with the network  1020 . In further examples, the communication components  1036  may include wired communication components, wireless communication components, cellular communication components, Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components to provide communication via other modalities. The devices  1022  may be another machine or any of a wide variety of peripheral devices (e.g., a peripheral device coupled via a USB). 
     Moreover, the communication components  1036  may detect identifiers or include components operable to detect identifiers. For example, the communication components  1036  may include Radio Frequency Identification (RFID) tag reader components, NFC smart tag detection components, optical reader components (e.g., an optical sensor to detect one-dimensional bar codes such as Universal Product Code (UPC) bar code, multi-dimensional bar codes such as Quick Response (QR) code, Aztec code, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2D bar code, and other optical codes), or acoustic detection components (e.g., microphones to identify tagged audio signals). In addition, a variety of information may be derived via the communication components  1036 , such as location via Internet Protocol (IP) geolocation, location via Wi-Fi® signal triangulation, location via detecting an NFC beacon signal that may indicate a particular location, and so forth. 
     The various memories (e.g., main memory  1012 , static memory  1014 , and memory of the processors  1002 ) and storage unit  1016  may store one or more sets of instructions and data structures (e.g., software) embodying or used by any one or more of the methodologies or functions described herein. These instructions (e.g., the instructions  1008 ), when executed by processors  1002 , cause various operations to implement the disclosed examples. 
     The instructions  1008  may be transmitted or received over the network  1020 , using a transmission medium, via a network interface device (e.g., a network interface component included in the communication components  1036 ) and using any one of several well-known transfer protocols (e.g., HTTP). Similarly, the instructions  1008  may be transmitted or received using a transmission medium via a coupling (e.g., a peer-to-peer coupling) to the devices  1022 . 
     Software Architecture 
       FIG.  11    is a block diagram  1100  illustrating a software architecture  1104 , which can be installed on any one or more of the devices described herein. The software architecture  1104  is supported by hardware such as a machine  1102  that includes processors  1120 , memory  1126 , and I/O components  1138 . In this example, the software architecture  1104  can be conceptualized as a stack of layers, where each layer provides a particular functionality. The software architecture  1104  includes layers such as an operating system  1112 , libraries  1110 , frameworks  1108 , and applications  1106 . Operationally, the applications  1106  invoke API calls  1150  through the software stack and receive messages  1152  in response to the API calls  1150 . 
     The operating system  1112  manages hardware resources and provides common services. The operating system  1112  includes, for example, a kernel  1114 , services  1116 , and drivers  1122 . The kernel  1114  acts as an abstraction layer between the hardware and the other software layers. For example, the kernel  1114  provides memory management, processor management (e.g., scheduling), component management, networking, and security settings, among other functionalities. The services  1116  can provide other common services for the other software layers. The drivers  1122  are responsible for controlling or interfacing with the underlying hardware. For instance, the drivers  1122  can include display drivers, camera drivers, BLUETOOTH® or BLUETOOTH® Low Energy drivers, flash memory drivers, serial communication drivers (e.g., USB drivers), WI-FI® drivers, audio drivers, power management drivers, and so forth. 
     The libraries  1110  provide a common low-level infrastructure used by applications  1106 . The libraries  1110  can include system libraries  1118  (e.g., C standard library) that provide functions such as memory allocation functions, string manipulation functions, mathematic functions, and the like. In addition, the libraries  1110  can include API libraries  1124  such as media libraries (e.g., libraries to support presentation and manipulation of various media formats such as Moving Picture Experts Group-4 (MPEG4), Advanced Video Coding (H.264 or AVC), Moving Picture Experts Group Layer-3 (MP3), Advanced Audio Coding (AAC), Adaptive Multi-Rate (AMR) audio codec, Joint Photographic Experts Group (JPEG or JPG), or Portable Network Graphics (PNG)), graphics libraries (e.g., an OpenGL framework used to render in 2D and 3D in a graphic content on a display), database libraries (e.g., SQLite to provide various relational database functions), web libraries (e.g., WebKit to provide web browsing functionality), and the like. The libraries  1110  can also include a wide variety of other libraries  1128  to provide many other APIs to the applications  1106 . 
     The frameworks  1108  provide a common high-level infrastructure that is used by the applications  1106 . For example, the frameworks  1108  provide various graphical user interface functions, high-level resource management, and high-level location services. The frameworks  1108  can provide a broad spectrum of other APIs that can be used by the applications  1106 , some of which may be specific to a particular operating system or platform. 
     In an example, the applications  1106  may include a home application  1136 , a contacts application  1130 , a browser application  1132 , a book reader application  1134 , a location application  1142 , a media application  1144 , a messaging application  1146 , a game application  1148 , and a broad assortment of other applications such as an external application  1140 . The applications  1106  are programs that execute functions defined in the programs. Various programming languages can be employed to create one or more of the applications  1106 , structured in a variety of manners, such as object-oriented programming languages (e.g., Objective-C, Java, or C++) or procedural programming languages (e.g., C or assembly language). In a specific example, the external application  1140  (e.g., an application developed using the ANDROID™ or IOS™ SDK by an entity other than the vendor of the particular platform) may be mobile software running on a mobile operating system such as IOS™, ANDROID™, WINDOWS® Phone, or another mobile operating system. In this example, the external application  1140  can invoke the API calls  1150  provided by the operating system  1112  to facilitate functionality described herein. 
     Glossary 
     “Carrier signal” refers to any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible media to facilitate communication of such instructions. Instructions may be transmitted or received over a network using a transmission medium via a network interface device. 
     “Client device” refers to any machine that interfaces to a communications network to obtain resources from one or more server systems or other client devices. A client device may be, but is not limited to, a mobile phone, desktop computer, laptop, portable digital assistant (PDA), smartphone, tablet, ultrabook, netbook, laptop, multi-processor system, microprocessor-based or programmable consumer electronics, game console, set-top box, or any other communication device that a user may use to access a network. 
     “Communication network” refers to one or more portions of a network that may be an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), the Internet, a portion of the Internet, a portion of the Public Switched Telephone Network (PSTN), a plain old telephone service (POTS) network, a cellular telephone network, a wireless network, a Wi-Fi® network, another type of network, or a combination of two or more such networks. For example, a network or a portion of a network may include a wireless or cellular network and the coupling may be a Code Division Multiple Access (CDMA) connection, a Global System for Mobile communications (GSM) connection, or other types of cellular or wireless coupling. In this example, the coupling may implement any of a variety of types of data transfer technology, such as Single Carrier Radio Transmission Technology (1×RTT), Evolution-Data Optimized (EVDO) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for GSM Evolution (EDGE) technology, third Generation Partnership Project (3GPP) including 3G, fourth generation wireless (4G) networks, Universal Mobile Telecommunications System (UNITS), High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX), Long Term Evolution (LTE) standard, others defined by various standard-setting organizations, other long-range protocols, or other data transfer technology. 
     “Component” refers to a device, physical entity, or logic having boundaries defined by function or subroutine calls, branch points, APIs, or other technologies that provide for the partitioning or modularization of particular processing or control functions. Components may be combined via their interfaces with other components to carry out a machine process. A component may be a packaged functional hardware unit designed for use with other components and a part of a program that usually performs a particular function of related functions. 
     Components may constitute either software components (e.g., code embodied on a machine-readable medium) or hardware components. A “hardware component” is a tangible unit capable of performing certain operations and may be configured or arranged in a certain physical manner. In various examples, one or more computer systems (e.g., a standalone computer system, a client computer system, or a server computer system) or one or more hardware components of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware component that operates to perform certain operations as described herein. 
     A hardware component may also be implemented mechanically, electronically, or any suitable combination thereof. For example, a hardware component may include dedicated circuitry or logic that is permanently configured to perform certain operations. A hardware component may be a special-purpose processor, such as a field-programmable gate array (FPGA) or an ASIC. A hardware component may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware component may include software executed by a general-purpose processor or other programmable processor. Once configured by such software, hardware components become specific machines (or specific components of a machine) uniquely tailored to perform the configured functions and are no longer general-purpose processors. It will be appreciated that the decision to implement a hardware component mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software), may be driven by cost and time considerations. Accordingly, the phrase “hardware component” (or “hardware-implemented component”) should be understood to encompass a tangible entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. 
     Considering examples in which hardware components are temporarily configured (e.g., programmed), each of the hardware components need not be configured or instantiated at any one instance in time. For example, where a hardware component comprises a general-purpose processor configured by software to become a special-purpose processor, the general-purpose processor may be configured as respectively different special-purpose processors (e.g., comprising different hardware components) at different times. Software accordingly configures a particular processor or processors, for example, to constitute a particular hardware component at one instance of time and to constitute a different hardware component at a different instance of time. 
     Hardware components can provide information to, and receive information from, other hardware components. Accordingly, the described hardware components may be regarded as being communicatively coupled. Where multiple hardware components exist contemporaneously, communications may be achieved through signal transmission (e.g., over appropriate circuits and buses) between or among two or more of the hardware components. In examples in which multiple hardware components are configured or instantiated at different times, communications between such hardware components may be achieved, for example, through the storage and retrieval of information in memory structures to which the multiple hardware components have access. For example, one hardware component may perform an operation and store the output of that operation in a memory device to which it is communicatively coupled. A further hardware component may then, at a later time, access the memory device to retrieve and process the stored output. Hardware components may also initiate communications with input or output devices, and can operate on a resource (e.g., a collection of information). 
     The various operations of example methods described herein may be performed, at least partially, by one or more processors that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented components that operate to perform one or more operations or functions described herein. As used herein, “processor-implemented component” refers to a hardware component implemented using one or more processors. Similarly, the methods described herein may be at least partially processor-implemented, with a particular processor or processors being an example of hardware. For example, at least some of the operations of a method may be performed by one or more processors  1002  or processor-implemented components. Moreover, the one or more processors may also operate to support performance of the relevant operations in a “cloud computing” environment or as a “software as a service” (SaaS). For example, at least some of the operations may be performed by a group of computers (as examples of machines including processors), with these operations being accessible via a network (e.g., the Internet) and via one or more appropriate interfaces (e.g., an API). The performance of certain of the operations may be distributed among the processors, not only residing within a single machine, but deployed across a number of machines. In some examples, the processors or processor-implemented components may be located in a single geographic location (e.g., within a home environment, an office environment, or a server farm). In other examples, the processors or processor-implemented components may be distributed across a number of geographic locations. 
     “Computer-readable storage medium” refers to both machine-storage media and transmission media. Thus, the terms include both storage devices/media and carrier waves/modulated data signals. The terms “machine-readable medium,” “computer-readable medium,” and “device-readable medium” mean the same thing and may be used interchangeably in this disclosure. 
     “Ephemeral message” refers to a message that is accessible for a time-limited duration. An ephemeral message may be a text, an image, a video, and the like. The access time for the ephemeral message may be set by the message sender. Alternatively, the access time may be a default setting or a setting specified by the recipient. Regardless of the setting technique, the message is transitory. 
     “Machine storage medium” refers to a single or multiple storage devices and media (e.g., a centralized or distributed database, and associated caches and servers) that store executable instructions, routines, and data. The term shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media, including memory internal or external to processors. Specific examples of machine-storage media, computer-storage media and device-storage media include non-volatile memory, including by way of example semiconductor memory devices, e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), FPGA, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks The terms “machine-storage medium,” “device-storage medium,” and “computer-storage medium” mean the same thing and may be used interchangeably in this disclosure. The terms “machine-storage media,” “computer-storage media,” and “device-storage media” specifically exclude carrier waves, modulated data signals, and other such media, at least some of which are covered under the term “signal medium.” 
     “Non-transitory computer-readable storage medium” refers to a tangible medium that is capable of storing, encoding, or carrying the instructions for execution by a machine. 
     “Signal medium” refers to any intangible medium that is capable of storing, encoding, or carrying the instructions for execution by a machine and includes digital or analog communications signals or other intangible media to facilitate communication of software or data. The term “signal medium” shall be taken to include any form of a modulated data signal, carrier wave, and so forth. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a matter as to encode information in the signal. The terms “transmission medium” and “signal medium” mean the same thing and may be used interchangeably in this disclosure. 
     Changes and modifications may be made to the disclosed examples without departing from the scope of the present disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure, as expressed in the following claims.