Patent Publication Number: US-11651019-B2

Title: Contextual media filter search

Description:
PRIORITY 
     This application is a continuation of U.S. application Ser. No. 16/814,221, filed Mar. 10, 2020, which claims the benefit of priority to U.S. Provisional Patent application Ser. No. 62/826,679, filed Mar. 29, 2019, each of which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate generally to mobile computing technology and, more particularly, but not by way of limitation, to systems for generating and displaying dynamic contextual media content at a client device. 
     BACKGROUND 
     Augmented reality (AR), is a live direct or indirect view of a physical, real-world environment whose elements are augmented by computer-generated sensory inputs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. Some embodiments are illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which: 
       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. 
         FIG.  1    is a diagrammatic representation of a networked environment in which the present disclosure may be deployed, in accordance with some example embodiments. 
         FIG.  2    is a diagrammatic representation of a messaging client application, in accordance with some example embodiments. 
         FIG.  3    is a diagrammatic representation of a data structure as maintained in a database, in accordance with some example embodiments. 
         FIG.  4    is a diagrammatic representation of a message, in accordance with some example embodiments. 
         FIG.  5    is a flowchart for an access-limiting process, in accordance with some example embodiments. 
         FIG.  6    is a block diagram illustrating components of the contextual media filter system, according to some example embodiments. 
         FIG.  7    is a flowchart depicting a method of causing display of a contextual media filter according to certain example embodiments. 
         FIG.  8    is a diagrammatic illustration of an object within an image frame, according to some example embodiments. 
         FIG.  9    is a diagrammatic illustration of a contextual media filter system within a user interface, according to some example embodiments. 
         FIG.  10    is block diagram showing a software architecture within which the present disclosure may be implemented, in accordance with some example embodiments. 
         FIG.  11    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, in accordance with some example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present subject matter. However, it will be apparent to one of ordinary skill in the art that embodiments of the subject matter described may be practiced without the specific details presented herein, or in various combinations, as described herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the described embodiments. Various examples may be given throughout this description. These are merely descriptions of specific embodiments. The scope or meaning of the claims is not limited to the examples given. 
     AR systems provide users within graphical user interfaces (GUIs) to display a live direct or indirect view of a physical, real-world environment, wherein elements of the view are augmented by computer-generated sensory inputs. For example, an AR interface may present media content at positions within a display of a view of a real-world environment, such that the media content appears to interact with elements in the real-world environment. 
     Aspects of the present disclosure describe a contextual media filter system configured to generate and display contextual media filters at a client device. For example, the contextual media filter system is configured to perform operations that include, receiving an input onto a graphical user interface at a client device, capturing an image frame at the client device, the image frame comprising a depiction of an object, identifying the object within the image frame, accessing media content associated with the object within a media repository in response to identifying the object, and causing presenting of the media content within the image frame at the client device. 
     The media content may include animated Graphics Interchange Format (GIF) images, of various shapes, sizes and themes. In some embodiments, the contextual media filter system may be in communication with a media repository that comprises a sorted and labeled collection of the media content, wherein the media content within the collection of media content is labeled or tagged based on attributes of the media content. For example, the media content may be tagged with a label that identifies an object category of the media content, such as “food,” or “basketball,” such that a reference to the object category corresponds with a set of media content from among the collection of media content. 
     In some embodiments, responsive to receiving an input that selects a user option from among a set of user options, the contextual media filter system captures an image from a client device, wherein the image frame comprises a depiction of one or more objects in a real-world environment. For example, the contextual media filter system may detect one or more local features (e.g., first set of features) within the image frame, wherein the local features identify an object associated with the object depicted in the image frame, or in further embodiments may also employ one or more image and text recognition techniques to identify the object depicted in the image frame. Based on the identification of the object, the contextual media filter system retrieves a set of representative features associated with the local features to compute global features (e.g., second set of features) of the image frame. The contextual media filter system may use the global features and query a media repository to identify media content based on the local features and the representative features. The contextual media filter system further geometrically verifies the media content using the local features and eliminates false media content from the media content. 
     In response to identifying the set of media content from the media repository, the contextual media filter system generates and causes display of the set of media content at the client device. In some embodiments, to generate the presentation of the set of media content, the contextual media filter system retrieves a media template that provides a presentation format and layout for the set of media content. For example, the media template may define positions to present the set of media content within the image frame at the client device. In some embodiments, the presentation of the set of media content within the image frame at the client device may be based on a position (or positions) of the objects identified within the image frame. 
       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 application  104 . Each messaging client application  104  is communicatively coupled to other instances of the messaging client application  104  and a messaging server system  108  via a network  106  (e.g., the Internet). 
     A messaging client application  104  is able to communicate and exchange data with another messaging client application  104  and with the messaging server system  108  via the network  106 . The data exchanged between messaging client application  104 , and between a messaging client application  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  106  to a particular messaging client application  104 . While certain functions of the messaging system  100  are described herein as being performed by either a messaging client application  104  or by the messaging server system  108 , the location of certain functionality either within the messaging client application  104  or the messaging server system  108  is 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 application  104  where a client device  102  has a sufficient processing capacity. 
     The messaging server system  108  supports various services and operations that are provided to the messaging client application  104 . Such operations include transmitting data to, receiving data from, and processing data generated by the messaging client application  104 . This data may include, message content, client device information, geolocation information, media annotation 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 (UIs) of the messaging client application  104 . 
     Turning now specifically to the messaging server system  108 , an Application Program Interface (API) server  110  is coupled to, and provides a programmatic interface to, an application server  112 . The application server  112  is communicatively coupled to a database server  118 , which facilitates access to a database  120  in which is stored data associated with messages processed by the application server  112 . 
     The Application Program Interface (API) server  110  receives and transmits message data (e.g., commands and message payloads) between the client device  102  and the application server  112 . Specifically, the Application Program Interface (API) server  110  provides a set of interfaces (e.g., routines and protocols) that can be called or queried by the messaging client application  104  in order to invoke functionality of the application server  112 . The Application Program Interface (API) server  110  exposes various functions supported by the application server  112 , including account registration, login functionality, the sending of messages, via the application server  112 , from a particular messaging client application  104  to another messaging client application  104 , the sending of media files (e.g., images or video) from a messaging client application  104  to the messaging server application  114 , and for possible access by another messaging client application  104 , the setting 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 adding and deletion of friends to a social graph, the location of friends within a social graph, and opening an application event (e.g., relating to the messaging client application  104 ). 
     The application server  112  hosts a number of applications and subsystems, including a messaging server application  114 , an image processing system  116 , a social network system  122  and a contextual media filter system  124 . 
     The contextual media filter system  124  is configured to capture an image frame that includes a depiction of an object from a client device  102 , identify one or more objects within the image frame based on the depiction of the object, identify one or more image features based on the object, retrieve a set of media content based on the image features, and cause display of a presentation of the set of media content within the image frame at the client device  102 , according to some example embodiments. Further details of the contextual media filter system  124  can be found in  FIG.  6    below. 
     The messaging server application  114  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 application  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, by the messaging server application  114 , to the messaging client application  104 . Other processor and memory intensive processing of data may also be performed server-side by the messaging server application  114 , in view of the hardware requirements for such processing. 
     The application server  112  also includes an image processing system  116  that is dedicated to performing various image processing operations, typically with respect to images or video received within the payload of a message at the messaging server application  114 . 
     The social network system  122  supports various social networking functions services and makes these functions and services available to the messaging server application  114 . To this end, the social network system  122  maintains and accesses an entity graph  304  (as shown in  FIG.  3   ) within the database  120 . Examples of functions and services supported by the social network system  122  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. 
     The application server  112  is communicatively coupled to a database server  118 , which facilitates access to a database  120  in which is stored data associated with messages processed by the messaging server application  114 . 
       FIG.  2    is block diagram illustrating further details regarding the messaging system  100 , according to example embodiments. Specifically, the messaging system  100  is shown to comprise the messaging client application  204  and the application server  212 , which in turn embody a number of some subsystems, namely an ephemeral timer system  202 , a collection management system  206  and an annotation system  208 . 
     The ephemeral timer system  202  is responsible for enforcing the temporary access to content permitted by the messaging client application  204  and the messaging server application  114 . To this end, 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 display and enable access to messages and associated content via the messaging client application  204 . Further details regarding the operation of the ephemeral timer system  202  are provided below. 
     The collection management system  206  is responsible for managing collections of media (e.g., collections of text, image video and audio data). In some examples, 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  206  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 application  204 . 
     The collection management system  206  furthermore includes a curation interface  210  that allows a collection manager to manage and curate a particular collection of content. For example, the curation interface  210  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  206  employs machine vision (or image recognition technology) and content rules to automatically curate a content collection. In certain embodiments, compensation may be paid to a user for inclusion of user-generated content into a collection. In such cases, the curation interface  210  operates to automatically make payments to such users for the use of their content. 
     The annotation system  208  provides various functions that enable a user to annotate or otherwise modify or edit media content associated with a message. For example, the annotation system  208  provides functions related to the generation and publishing of media overlays for messages processed by the messaging system  100 . The annotation system  208  operatively supplies a media overlay or supplementation (e.g., an image filter) to the messaging client application  204  based on a geolocation of the client device  102 . In another example, the annotation system  208  operatively supplies a media overlay to the messaging client application  204  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 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 annotation 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  120  and accessed through the database server  118 . 
     In one example embodiment, the annotation 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 annotation system  208  generates a media overlay that includes the uploaded content and associates the uploaded content with the selected geolocation. 
     In another example embodiment, the annotation 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 annotation system  208  associates the media overlay of a highest bidding merchant with a corresponding geolocation for a predefined amount of time. 
       FIG.  3    is a schematic diagram illustrating data structures  300  which may be stored in the database  316  of the messaging server system  108 , according to certain example embodiments. While the content of the database  316  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  316  includes message data stored within a message table  314 . The entity table  302  stores entity data, including an entity graph  304 . Entities for which records are maintained within the entity table  302  may include individuals, corporate entities, organizations, objects, places, events, etc. Regardless of 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  304  furthermore 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 database  316  also stores annotation data, in the example form of filters, in an annotation table  312 . Filters for which data is stored within the annotation table  312  are associated with and applied to videos (for which data is stored in a video table  310 ) and/or images (for which data is stored in an image table  308 ). 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 varies types, including user-selected filters from a gallery of filters presented to a sending user by the messaging client application  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 application  104 , based on geolocation information determined by a GPS unit of the client device  102 . Another type of filer is a data filer, which may be selectively presented to a sending user by the messaging client application  104 , based on other inputs or information gathered by the client device  102  during the message creation process. Example 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 annotation data that may be stored within the image table  308  is so-called Lenses® data. Lenses® may be a real-time special effect and sound that may be added to an image or a video. 
     In a social messaging system, content (e.g. images and video clips) may be communicated as part of the messaging. One way of customizing such content is the use of Lenses® which modifies or transforms the content in some way. For example, complex additions or transformations to the content images may be performed using Lenses® data, such as adding rabbit ears to the head of a person in a video clip, adding floating hearts with background coloring to a video clip, altering the proportions of a person&#39;s features within a video clip, or many numerous other such transformations. In order to both provide unique user experiences, to provide attribution to Lenses® creators, and to enable creators to protect various aspects of data within the messaging system, the system may provide tools both for users to generate and share such Lenses®, as well as limiting access to such filters in various ways. As described above, Lenses® in accordance with embodiments described herein refer to modifications that may be made to videos or images. This includes both real-time modification which modifies an image as it is captured using a device sensor and then displayed on a screen of the device with the le Lenses® ns modifications. This also includes modifications to stored content, such as video clips in a gallery that may be modified using Lenses®. For example, in a creator profile with multiple Lenses®, an authorized third party account may use a single video clip with multiple Lenses® to see how the different Lenses® will modify the stored clip. Similarly, real-time video capture may be used with Lenses® to show how video images currently being captured by sensors of a device 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 Lenses® modifications (or both). 
     Lenses® data and various systems to use Lenses® and modify content using Lenses® may 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. I various embodiments, different methods for achieving such transformations may be used. For example, some embodiments may involve generating a three-dimensional 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 embodiments, tracking of points on an object may be used to place an image or texture (which may be two dimensional or three dimensional) at the tracked position. In still further embodiments, neural network analysis of video frames may be used to place images, models, or textures in content (e.g. images or frames of video). Lenses® data thus refers 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 Lenses®, 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 embodiments, when a Lenses® is selected along with content to be transformed, elements to be transformed by the Lenses® 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 object&#39;s elements characteristic points for each of 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 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 one or more embodiments, transformations changing some areas of an object using its elements can be performed by calculating of 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 element, 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 embodiments, any combination of such modifications or other similar modifications may be used. 
     In some embodiments, Lenses® may provide augmented reality (AR) experiences. For example the AR experiences may provide an interactive experience of a real-world environment where the objects within the real-world environment are enhanced by computer-generated information such as video and audio. 
     In some embodiments of Lenses® using face detection, the face is detected on an image with use of a specific face detection algorithm (e.g. Viola-Jones). Then, an Active Shape Model (ASM) algorithm is applied to the face region of an image to detect facial feature reference points. 
     In other embodiments, other methods and algorithms suitable for face detection can be used. For example, in some embodiments, 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. In 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 embodiments, 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 embodiments, a search for landmarks from the mean shape aligned to the position and size of the face determined by a global face detector is started. 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 matchers to form a stronger overall classifier. The entire search is repeated at each level in an image pyramid, from coarse to fine resolution. 
     Embodiments of a transformation system can capture an image or video stream on a client device and perform complex image manipulations locally on a client device such as 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 a client device. 
     In some example embodiments, Lenses® may 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 application  104  operating on the client device  102 . The transform system operating within the messaging application  104  determines the presence of a face within the image or video stream and provides modification icons associated with the Lenses®, or the Lenses® may be present as associated with an interface described herein. The modification icons include changes which may be the basis for modifying the user&#39;s face within the image or video stream as part of the Lenses® operation. Once a modification icon is selected, the transform 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). In some embodiments, a modified image or video stream may be presented in a graphical user interface displayed on the mobile client device as soon as the image or video stream is captured and a specified modification is selected. The transform 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. 
     In some embodiments, the graphical user interface, presenting the modification performed by the transform system, may supply the user with additional interaction options. Such options may be based on the interface used to initiate the content capture and Lenses® selection (e.g. initiation from a content creator user interface) In various embodiments, 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 embodiments, 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. 
     As mentioned above, the video table  310  stores video data which, in one embodiment, is associated with messages for which records are maintained within the message table  314 . Similarly, the image table  308  stores image data associated with messages for which message data is stored in the entity table  302 . The entity table  302  may associate various annotations from the annotation table  312  with various images and videos stored in the image table  308  and the video table  310 . 
     A story table  306  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  302 ). 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 application  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 varies 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 application  104 , to contribute content to a particular live story. The live story may be identified to the user by the messaging client application  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 embodiments, 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). 
       FIG.  4    is a schematic diagram illustrating a structure of a message  400 , according to some in some embodiments, generated by a messaging client application  104  for communication to a further messaging client application  204  or the messaging server application  114 . The content of a particular message  400  is used to populate the message table  314  stored within the database  120 , accessible by the messaging server application  114 . 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 server  112 . The message  400  is shown to include the following components:
         A message identifier  402 : a unique identifier that identifies the message  400 .   A message text payload  406 : text, to be generated by a user via a user interface of the client device  102  and that is included in the message  400 .   A message image payload  408 : 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 .   A message video payload  412 : 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 .   A message audio payload  416 : 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 .   A message annotations  420 : annotation data (e.g., filters, stickers or other enhancements) that represents annotations to be applied to message image payload  408 , message video payload  412 , or message audio payload  416  of the message  400 .   A message duration parameter  424 : parameter value indicating, in seconds, the amount of time for which content of the message (e.g., the message image payload  408 , message video payload  412 , message audio payload  416 ) is to be presented or made accessible to a user via the messaging client application  104 .   A message geolocation parameter  426 : geolocation data (e.g., latitudinal and longitudinal coordinates) associated with the content payload of the message. Multiple message geolocation parameter  426  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 into within the message image payload  408 , or a specific video in the message video payload  412 ).   A message story identifier  428 : identifier values identifying one or more content collections (e.g., “stories”) with which a particular content item in the message image payload  408  of the message  400  is associated. For example, multiple images within the message image payload  408  may each be associated with multiple content collections using identifier values.   A message tag  430 : 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  408  depicts an animal (e.g., a lion), a tag value may be included within the message tag  430  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.   A message sender identifier  432 : 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   A message receiver identifier  434 : 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  408  may be a pointer to (or address of) a location within an image table  414 . Similarly, values within the message video payload  412  may point to data stored within a video table  418 , values stored within the message annotations  420  may point to data stored in an annotation table  422 , values stored within the message story identifier  428  may point to data stored in a story table  410 , and values stored within the message sender identifier  432  and the message receiver identifier  434  may point to user records stored within an entity table  404 . 
       FIG.  5    is a schematic diagram illustrating an access-limiting process  500 , in terms of which access to content (e.g., an ephemeral message  502 , and associated multimedia payload of data) or a content collection (e.g., an ephemeral message group  506 ) may be time-limited (e.g., made ephemeral). 
     An ephemeral message  502  is shown to be associated with a message duration parameter  508 , the value of which determines an amount of time that the ephemeral message  502  will be displayed to a receiving user of the ephemeral message  502  by the messaging client application  104 . In one embodiment, an ephemeral message  502  is viewable by a receiving user for up to a maximum of 10 seconds, depending on the amount of time that the sending user specifies using the message duration parameter  508 . 
     The message duration parameter  508  and the message receiver identifier  518  are shown to be inputs to a message timer  514 , which is responsible for determining the amount of time that the ephemeral message  502  is shown to a particular receiving user identified by the message receiver identifier  518 . In particular, the ephemeral message  502  will only be shown to the relevant receiving user for a time period determined by the value of the message duration parameter  508 . The message timer  514  is shown to provide output to a more generalized ephemeral timer system  504 , which is responsible for the overall timing of display of content (e.g., an ephemeral message  502 ) to a receiving user. 
     The ephemeral message  502  is shown in  FIG.  5    to be included within an ephemeral message group  506  (e.g., a collection of messages in a personal story, or an event story). The ephemeral message group  506  has an associated group duration parameter  510 , a value of which determines a time-duration for which the ephemeral message group  506  is presented and accessible to users of the messaging system  100 . The group duration parameter  510 , for example, may be the duration of a music concert, where the ephemeral message group  506  is a collection of content pertaining to that concert. Alternatively, a user (either the owning user or a curator user) may specify the value for the group duration parameter  510  when performing the setup and creation of the ephemeral message group  506 . 
     Additionally, each ephemeral message  502  within the ephemeral message group  506  has an associated group participation parameter  512 , a value of which determines the duration of time for which the ephemeral message  502  will be accessible within the context of the ephemeral message group  506 . Accordingly, a particular ephemeral message group  506  may “expire” and become inaccessible within the context of the ephemeral message group  506 , prior to the ephemeral message group  506  itself expiring in terms of the group duration parameter  510 . The group duration parameter  510 , group participation parameter  512 , and message receiver identifier  518  each provide input to a group timer  516 , which operationally determines, firstly, whether a particular ephemeral message  502  of the ephemeral message group  506  will be displayed to a particular receiving user and, if so, for how long. Note that the ephemeral message group  506  is also aware of the identity of the particular receiving user as a result of the message receiver identifier  518 . 
     Accordingly, the group timer  516  operationally controls the overall lifespan of an associated ephemeral message group  506 , as well as an individual ephemeral message  502  included in the ephemeral message group  506 . In one embodiment, each and every ephemeral message  502  within the ephemeral message group  506  remains viewable and accessible for a time-period specified by the group duration parameter  510 . In a further embodiment, a certain ephemeral message  502  may expire, within the context of ephemeral message group  506 , based on a group participation parameter  512 . Note that a message duration parameter  508  may still determine the duration of time for which a particular ephemeral message  502  is displayed to a receiving user, even within the context of the ephemeral message group  506 . Accordingly, the message duration parameter  508  determines the duration of time that a particular ephemeral message  502  is displayed to a receiving user, regardless of whether the receiving user is viewing that ephemeral message  502  inside or outside the context of an ephemeral message group  506 . 
     The ephemeral timer system  504  may furthermore operationally remove a particular ephemeral message  502  from the ephemeral message group  506  based on a determination that it has exceeded an associated group participation parameter  512 . For example, when a sending user has established a group participation parameter  512  of 24 hours from posting, the ephemeral timer system  504  will remove the relevant ephemeral message  502  from the ephemeral message group  506  after the specified 24 hours. The ephemeral timer system  504  also operates to remove an ephemeral message group  506  either when the group participation parameter  512  for each and every ephemeral message  502  within the ephemeral message group  506  has expired, or when the ephemeral message group  506  itself has expired in terms of the group duration parameter  510 . 
     In certain use cases, a creator of a particular ephemeral message group  506  may specify an indefinite group duration parameter  510 . In this case, the expiration of the group participation parameter  512  for the last remaining ephemeral message  502  within the ephemeral message group  506  will determine when the ephemeral message group  506  itself expires. In this case, a new ephemeral message  502 , added to the ephemeral message group  506 , with a new group participation parameter  512 , effectively extends the life of an ephemeral message group  506  to equal the value of the group participation parameter  512 . 
     Responsive to the ephemeral timer system  504  determining that an ephemeral message group  506  has expired (e.g., is no longer accessible), the ephemeral timer system  504  communicates with the messaging system  100  (and, for example, specifically the messaging client application  104  to cause an indicium (e.g., an icon) associated with the relevant ephemeral message group  506  to no longer be displayed within a user interface of the messaging client application  104 . Similarly, when the ephemeral timer system  202  determines that the message duration parameter  508  for a particular ephemeral message  502  has expired, the ephemeral timer system  504  causes the messaging client application  104  to no longer display an indicium (e.g., an icon or textual identification) associated with the ephemeral message  502 . 
       FIG.  6    is a block diagram illustrating components of the contextual media filter system  124  that configure the contextual media filter system  124  to capture an image frame that includes a depiction of an object from a client device  102 , identify one or more objects within the image frame based on the depiction of the object, identify one or more image features based on the object, retrieve a set of media content based on the image features, and cause display of a presentation of the set of media content within the image frame at the client device  102 , according to some example embodiments. 
     The contextual media filter system  124  is shown as including a presentation system  604 , image feature computation system  606 , a search system  608 , and a geometric verification system  610 , all configured to communicate with each other (e.g., via bus, shared memory, or a switch). Any one or more of these systems may be implemented using one or more processors (e.g., by configuring such one or more processors to preform functions described for that system and hence may include one or more processors). 
     Any one or more of the systems described may be implemented using hardware alone (e.g., one or more of the processors of a machine) or a combination of hardware and software. For example, any system described of the contextual media filter system  124  may physically include an arrangement of one or more of the processors (e.g., a subset of or among the one or more processors of the machine) configured to perform the operations described herein for that system. As another example, any system of the contextual media filter system  124  may include software, hardware, or both, that configure an arrangement of one or more processors (e.g., among the one or more processors of the machine) to perform the operations described herein for that system. Accordingly, different systems of the contextual media filter system  124  may include and configure different arrangements of such processors or a single arrangement of such processors at different points in time. Moreover, any two or more systems of the contextual media filter system  124  may be combined into a single system, and the functions described herein for a single system may be subdivided among multiple systems. Furthermore, according to various example embodiments, systems described herein as being implemented within a single machine, database, or device may be distributed across multiple machines, databases, or devices. 
       FIG.  7    is a flowchart depicting a method  700  of causing display of a contextual media filter at a client device  102 , according to certain example embodiments. Operations of the method  700  may be performed by the systems described above with respect to  FIG.  6   . As showing in  FIG.  7   , the method  700  includes one or more operations  702 ,  704 ,  706 ,  708 , and  710 . 
     At operation  702  the communication system  602  receives an input from the client device  102 . In some embodiments, the client device  102  includes a touch-screen display configured to receive tactile inputs. The input may therefore include a tactile input onto a display of the client device  102 , wherein the tactile input provides an indication of a point or position within the graphical user interface (GUI). For example, a user of the client device  102  may provide an input to identify a location or object depicted within the GUI by providing a tactile input onto a location along the display that corresponds with a position of the location or object within the GUI. 
     In some embodiments, the input may comprise one or more input properties that include an input pressure, an input duration, and an input location. In such embodiments, the communication system  602  may compare one or more of the input properties against a set of threshold values. For example, responsive to detecting an input property transgress a threshold value, the communication system  602  may signal one or more systems of the contextual media filter system  124  to perform certain follow-up actions or operations. 
     At operation  704 , the presentation system  604  causes display of a of a GUI at the client device  102 , where the GUI comprises a display of live camera data streamed from a camera of or associated with the client device  102 . For example, the client device  102  may include a plurality of cameras such as one or more “front-facing” cameras, and one or more “back-facing” cameras, configured to capture and stream image data. The live camera data generated by the one or more cameras associated with the client device  102  may include image data that comprises a plurality of image features. 
     At operation  706  the image feature computation system  606  identifies the object within the image frame. The contextual media filter system  124  compares media content within the media repository (e.g., a database) and select those media content which are most visually similar to the object within the image frame. The visual similarity comparison is a unified abstraction and representation of the media content such that the similarity between two media content captured under, for example, different resolutions, angles, illuminations and other factors can be computed using the representation. 
     The image feature computation system  606  identifies local features that are computed from specific regions within the image frame. The local features are stored in an indexing structure. An indexing structure is a data structure that makes searching a database more efficient. Therefore, querying an index is faster than searching each row in a database. 
     Each local feature is further analyzed to compute global features of the image frame. Global features are computed from the entire image frame, not specific regions within the image frame. In one example, the global features are computed by quantizing local features of the image frame. Quantization involved in image processing is a technique achieved by compressing a range of values to a single value. The global features are computed by mapping each local feature to a representative feature in a set of representative features. Each representative feature may be referred to as a “word.” The global feature is computed by counting an occurrence of each representative feature in the set of representative features. 
     For example, a set of representative features may be (A, B, C, D, . . . ). The image feature computation system  606  may have computed 5 local features from the image. Two local features are mapped to “word” A, and 3 local features are mapped to “word” D. The global feature can be represented as “2A0B0C3D.” 
     At operation  708 , the search system  608  accesses media content associated with the object with the media repository in response to identifying the object. The search system  608  uses the global feature to search for media content within the indexing structure to retrieve media content from the media repository associated with object. In some examples, the search system  608  uses the k-nearest neighbors algorithm in performing the search. 
     At operation  708 , the contextual media filter system  124  further verifies the media content using the geometric verification system  610 . The media content returned by the search performed by the search system  608  may contain false media content matches that are not visually similar to the original object within the image frame. The geometric verification system  610  may use a similarity metric in determining whether a media content item is similar to the original object. The similarity metric may relate to a geometric constraint associated with the geometry of the original object. Therefore, the geometric verification system  610  identifies false media content using geometric verification and removes the false media content from the media content. 
     At operation  710 , the presentation system  604  causes presentation of the media content within the image frame at the client device  102 . For example, the presentation of the set of media content may include an AR display of the set of media content, such that the retrieved media content appears to interact with elements depicted within the image frame, in real time. 
     In some embodiments, to generate the presentation of the media content, the presentation system  604  retrieves a media template, wherein the media template defines a presentation format and layout to be applied to the set of media content. For example, the media template may define positions and orientations to present the media content within the image frame, at the client device  102 . The media content may be tagged with location information or temporal information within the media repository, such that reference to a particular time of day, season, day of week, month, or place, may identify a set of relevant media content. 
       FIG.  8    is a diagrammatic illustration of an object  800  within an image frame at a client device. In some examples the object is a custom image that can be tracked within the image frame. 
       FIG.  9    is a diagrammatic illustrations of a contextual media filter system  124  within a user interface  900  of a client device  102 . The contextual media filter system  124  may be initialized by initiating a scan of the image frame. Once the contextual media filter system  124  determines the media content associated with the object within the image frame, the contextual media filter system  124  may display a set of media content  902  that a user of a client device may swipe to select. 
     Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present subject matter. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment. 
       FIG.  10    is a block diagram  1000  illustrating a software architecture  1004 , which can be installed on any one or more of the devices described herein. The software architecture  1004  is supported by hardware such as a machine  1002  that includes processors  1020 , memory  1026 , and I/O components  1038 . In this example, the software architecture  1004  can be conceptualized as a stack of layers, where each layer provides a particular functionality. The software architecture  1004  includes layers such as an operating system  1012 , libraries  1010 , frameworks  1008 , and applications  1006 . Operationally, the applications  1006  invoke API calls  1050  through the software stack and receive messages  1052  in response to the API calls  1050 . 
     The operating system  1012  manages hardware resources and provides common services. The operating system  1012  includes, for example, a kernel  1014 , services  1016 , and drivers  1022 . The kernel  1014  acts as an abstraction layer between the hardware and the other software layers. For example, the kernel  1014  provides memory management, processor management (e.g., scheduling), component management, networking, and security settings, among other functionality. The services  1016  can provide other common services for the other software layers. The drivers  1022  are responsible for controlling or interfacing with the underlying hardware. For instance, the drivers  1022  can include display drivers, camera drivers, BLUETOOTH® or BLUETOOTH® Low Energy drivers, flash memory drivers, serial communication drivers (e.g., Universal Serial Bus (USB) drivers), WI-FI® drivers, audio drivers, power management drivers, and so forth. 
     The libraries  1010  provide a low-level common infrastructure used by the applications  1006 . The libraries  1010  can include system libraries  1018  (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  1010  can include API libraries  1024  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 two dimensions (2D) and three dimensions (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  1010  can also include a wide variety of other libraries  1028  to provide many other APIs to the applications  1006 . 
     The frameworks  1008  provide a high-level common infrastructure that is used by the applications  1006 . For example, the frameworks  1008  provide various graphical user interface (GUI) functions, high-level resource management, and high-level location services. The frameworks  1008  can provide a broad spectrum of other APIs that can be used by the applications  1006 , some of which may be specific to a particular operating system or platform. 
     In an example embodiment, the applications  1006  may include a home application  1036 , a contacts application  1030 , a browser application  1032 , a book reader application  1034 , a location application  1042 , a media application  1044 , a messaging application  1046 , a game application  1048 , and a broad assortment of other applications such as third-party applications  1040 . The applications  1006  are programs that execute functions defined in the programs. Various programming languages can be employed to create one or more of the applications  1006 , 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 third-party applications  1040  (e.g., applications developed using the ANDROID™ or IOS™ software development kit (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 third-party applications  1040  can invoke the API calls  1050  provided by the operating system  1012  to facilitate functionality described herein. 
       FIG.  11    is a diagrammatic representation of a machine  1100  within which instructions  1108  (e.g., software, a program, an application, an applet, an app, or other executable code) for causing the machine  1100  to perform any one or more of the methodologies discussed herein may be executed. For example, the instructions  1108  may cause the machine  1100  to execute any one or more of the methods described herein. The instructions  1108  transform the general, non-programmed machine  1100  into a particular machine  1100  programmed to carry out the described and illustrated functions in the manner described. The machine  1100  may operate as a standalone device or may be coupled (e.g., networked) to other machines. In a networked deployment, the machine  1100  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  1100  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 PDA, an entertainment media system, a cellular telephone, a smart phone, a mobile device, a wearable device (e.g., a smart watch), 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  1108 , sequentially or otherwise, that specify actions to be taken by the machine  1100 . Further, while only a single machine  1100  is illustrated, the term “machine” shall also be taken to include a collection of machines that individually or jointly execute the instructions  1108  to perform any one or more of the methodologies discussed herein. 
     The machine  1100  may include processors  1102 , memory  1104 , and I/O components  1142 , which may be configured to communicate with each other via a bus  1144 . In an example embodiment, the processors  1102  (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 ASIC, a Radio-Frequency Integrated Circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor  1106  and a processor  1110  that execute the instructions  1108 . 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.  11    shows multiple processors  1102 , the machine  1100  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  1104  includes a main memory  1112 , a static memory  1114 , and a storage unit  1116 , both accessible to the processors  1102  via the bus  1144 . The main memory  1104 , the static memory  1114 , and storage unit  1116  store the instructions  1108  embodying any one or more of the methodologies or functions described herein. The instructions  1108  may also reside, completely or partially, within the main memory  1112 , within the static memory  1114 , within machine-readable medium  1118  within the storage unit  1116 , within at least one of the processors  1102  (e.g., within the processor&#39;s cache memory), or any suitable combination thereof, during execution thereof by the machine  1100 . 
     The I/O components  1142  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  1142  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  1142  may include many other components that are not shown in  FIG.  11   . In various example embodiments, the I/O components  1142  may include output components  1128  and input components  1130 . The output components  1128  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 input components  1130  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/or force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like. 
     In further example embodiments, the I/O components  1142  may include biometric components  1132 , motion components  1134 , environmental components  1136 , or position components  1138 , among a wide array of other components. For example, the biometric components  1132  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  1134  include acceleration sensor components (e.g., accelerometer), gravitation sensor components, rotation sensor components (e.g., gyroscope), and so forth. The environmental components  1136  include, for example, 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. The position components  1138  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  1142  further include communication components  1140  operable to couple the machine  1100  to a network  1120  or devices  1122  via a coupling  1124  and a coupling  1126 , respectively. For example, the communication components  1140  may include a network interface component or another suitable device to interface with the network  1120 . In further examples, the communication components  1140  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  1122  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  1140  may detect identifiers or include components operable to detect identifiers. For example, the communication components  1140  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  1140 , 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., memory  1104 , main memory  1112 , static memory  1114 , and/or memory of the processors  1102 ) and/or storage unit  1116  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  1108 ), when executed by processors  1102 , cause various operations to implement the disclosed embodiments. 
     The instructions  1108  may be transmitted or received over the network  1120 , using a transmission medium, via a network interface device (e.g., a network interface component included in the communication components  1140 ) and using any one of a number of well-known transfer protocols (e.g., hypertext transfer protocol (HTTP)). Similarly, the instructions  1108  may be transmitted or received using a transmission medium via the coupling  1126  (e.g., a peer-to-peer coupling) to the devices  1122 .