Patent Publication Number: US-2022237366-A1

Title: Systems and methods for synchronizing graphical displays across thin client devices

Description:
TECHNICAL FIELD 
     The present disclosure relates to systems and methods for synchronizing graphical displays across a plurality of devices. More particularly, the present disclosure relates to systems and methods for synchronizing document markup modification across a plurality of devices. The present disclosure further relates to systems and methods for synchronizing document markup modification between thin client applications. 
     BACKGROUND 
     Creation, distribution, and management of information is at the core of modern day business. Many different ways of presenting information have been developed, including word processing documents, spreadsheets, graphics, photographs, design drawings and plans, and so forth. This information content may be generated using a specific software application. In an enterprise setting, multiple individuals may collaborate on creating, reviewing, editing, and/or deleting such information content. Due to advancement in high-speed data communications and computing devices, such collaboration may involve remote users dynamically viewing and making changes to information content, by exchanging pertinent data among each other in real-time. 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section. 
     SUMMARY OF THE DISCLOSURE 
     One embodiment provides a computer-implemented method for synchronizing a document markup modification across a plurality of devices, comprising: subscribing to one or more events occurring in a first document markup application, the first document markup application being a first thin client application; receiving a notification indicating a modification to a document markup in the first document markup application; extracting a cross-compatible markup object associated with the modified document markup; and transmitting the cross-compatible markup object to a second document markup application, the second document markup application being a second thin client application. 
     One embodiment provides a system for synchronizing a document markup modification across a plurality of devices. The system may comprise one or more processors; and at least one non-transitory computer readable medium storing instructions which, when executed by the one or more processors, cause the one or more processors to perform a method comprising: subscribing to one or more events occurring in a first document markup application, the first document markup application being a first thin client application; receiving a notification indicating a modification to a document markup in the first document markup application; extracting a cross-compatible markup object associated with the modified document markup; and transmitting the cross-compatible markup object to a second document markup application, the second document markup application being a second thin client application. 
     One embodiment provides a non-transitory computer readable medium for synchronizing a document markup modification across a plurality of devices. The non-transitory computer readable medium may store instructions that, when executed by one or more processors, cause the one or more processors to perform a method comprising: subscribing to one or more events occurring in a first document markup application, the first document markup application being a first thin client application; receiving a notification indicating a modification to a document markup in the first document markup application; extracting a cross-compatible markup object associated with the modified document markup; and transmitting the cross-compatible markup object to a second document markup application, the second document markup application being a second thin client application. 
     Additional objects and advantages of the disclosed embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the disclosed embodiments. The objects and advantages of the disclosed embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments. 
         FIG. 1  depicts an exemplary system infrastructure of communicatively coupled thin client(s), markup server(s), and thick client(s), according to one aspect of the present disclosure. 
         FIG. 2  depicts an exemplary embodiment of a document markup synchronization system, according to one aspect of the present disclosure. 
         FIG. 3  depicts exemplary graphical user interfaces (GUls) of thin client applications during a markup modification session, according to one aspect of the present disclosure. 
         FIG. 4  is a flowchart illustrating an exemplary method of extracting and transmitting a cross-compatible markup object by a thin client application, according to one aspect of the present disclosure. 
         FIG. 5  is a flowchart illustrating an exemplary method of receiving and transmitting a cross-compatible markup object by a master markup server, according to one aspect of the present disclosure. 
         FIG. 6  is a flowchart illustrating an exemplary method of translating a cross-compatible markup object to a native markup object by a markup translation server, according to one aspect of the present disclosure. 
         FIG. 7  depicts an exemplary cross-compatible markup object and a corresponding exemplary native markup object, according to one aspect of the present disclosure. 
         FIG. 8  depicts a system flowchart illustrating an exemplary method of synchronizing a document markup modification across a plurality of thin client devices, according to one aspect of the present disclosure. 
         FIG. 9  illustrates an implementation of a computer system that may execute techniques presented herein. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following embodiments describe systems and methods for synchronizing a document markup modification across a plurality of devices and, more particularly, for synchronizing a document markup modification between thin client applications. 
     Due to the existence of different computing platforms employing a variety of operating systems, application programs, and processing and graphic display capabilities, device-independent file formats, such as the Portable Document Format (PDF), have been developed to facilitate information exchange among different computing platforms. The PDF standard is a combination of a number of technologies, including a simplified PostScript interpreter subsystem, a font embedding subsystem, and a storage subsystem. PostScript is a page description language for generating the layout and the graphics of a document. Further, per the requirements of the PDF storage subsystem, all elements of the document, including text, vector graphics, and raster (bitmap) graphics, collectively referred to herein as graphic elements, are encapsulated in a single file. The graphical elements are not necessarily encoded to a specific operating system, software application, or hardware, but may be designed to be rendered in the same manner regardless of the specifications of the system writing or reading such data. The cross-platform capability of PDF aided its widespread adoption, and it is now a de facto document exchange standard. Although originally proprietary, PDF has been released as an open standard published by the International Organization for Standardization (ISO) as ISO/IEC 32000-2:2017. Currently, PDF is utilized to encode a wide variety of document types, including those composed largely of text, and those composed largely of vector and raster graphics. 
     One of several improvements that have been made since the initial release of the PDF format is support for adding markups to a base document. The markups are graphically overlaid on the underlying document, with various properties being precisely controlled by the user. Thus, the functionality is similar to graphical illustration/design and image manipulation applications where various objects can be positioned on a document canvas by navigating a cursor to a desired location and providing a subsequent input to make placement permanent. Before positioning the markup, the type of the markup may be selected (e.g., text box, line, polygon, note, ink, etc.). 
     Markups may be understood to be a type of data object that is associated with an underlying document, and may generally refer to a conceptual entity corresponding to a contiguous block of memory at a specific location and with a specific size. A markup may be defined by one or more properties that define its characteristics. A markup may be defined by a type, or a broad category of objects such as geometric primitives including points, lines (single segment or multi-segment), arcs, ellipses, polygons, and the like. Markups may also take more complex forms such as callout boxes, arrows, text/note boxes, and so forth. The PDF standard defines several common markup types that may be rendered similarly across diverse reader applications, though with slight variances in appearance from one implementation to another. The particular characteristics of the markup may be defined by one or more parameters including dimensions, placement location (e.g., positioning coordinates), color, line thickness, fill patterns and colors, and others that are specific to that markup type. Although markups may be stored in the document, they generally do not become a part of an underlying drawing; visually, the markups are overlaid on a separate layer of the document, such as over the main text and/or image layers. The markups may be allowed to be viewed when overlaid and may be toggled on or off as desired. 
     One way to develop collaborative document editing applications based on documents encoded in the PDF format, to enable remote users to collaboratively manipulate markups within PDF documents, is to create and utilize markup objects representative of modified markups. Such markup objects may be used to propagate or synchronize modified markups across user devices during collaborative sessions. The markup objects may be PDF dictionary objects extracted from PDF document files, each containing a set of key-value pairs that describe the attributes of the markup. Such a markup object (i.e., a PDF dictionary object) may also be referred to as a PDF markup object (in the sense that the markup object may be in PDF format), standard markup object (in the sense that the markup object may be in ISO-standardized format), a native markup object (in the sense that the markup object may be extracted from a PDF file and maintained/represented as a PDF dictionary object), and/or a proprietary or custom markup object (in the sense that the extraction and/or formation of the markup object may be performed according to a schema specific to or customized to an organization such as a company). Due to the nuances and complexity involved with processing such markup objects, a substantial amount of processing may be necessary at the recipient user&#39;s device to properly render and display the modified markups based on the markup objects. Therefore, collaborative PDF markup editing may require installation on a computer system having a substantial processing and storage capability (e.g., thick client), of an application specifically designed to manage collaborative sessions as well as process/interpret PDF markup objects in their native format. With the proliferation of computing device types with varying computing resources, computing devices with limited capabilities such as, for example, thin clients, may lack the necessary computing power or storage to install and run such an application. Furthermore, devices other than conventional desktop computers such as, mobile phones, tablets, gaming consoles, etc., may not be well suited for such an application. 
     Therefore, there is a need for an open, more ubiquitous and accessible format for markups, that is suitable for consumption by various client types and applications, such as thin client computing devices. Further, there is a need for a mechanism that enables markup collaboration across thin client computing devices. 
     One disclosed embodiment is directed to propagating a document markup modification across thin client computing devices, by utilizing cross-compatible markup objects (i.e., browser-friendly markup objects) that are more consumable by thin client computing devices than native markup objects (i.e., markup objects in native, PDF dictionary form). The disclosed embodiment may thus enable users of thin client computing devices to collaboratively modify document markups, and to view the modified document markups in their respective computing devices in real-time. Briefly, in one embodiment, a first thin client may subscribe to one or more events occurring in a document markup application, receive a notification indicating a modification to a document markup in the document markup application, extract a cross-compatible markup object associated with the modified document markup, and transmit the cross-compatible markup object to a second thin client. 
     The subject matter of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments. An embodiment or implementation described herein as “exemplary” is not to be construed as preferred or advantageous, for example, over other embodiments or implementations; rather, it is intended to reflect or indicate that the embodiment(s) is/are “example” embodiment(s). Subject matter may be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any exemplary embodiments set forth herein; exemplary embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, or systems. Accordingly, embodiments may, for example, take the form of hardware, software, firmware or any combination thereof. The following detailed description is, therefore, not intended to be taken in a limiting sense. 
     Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter include combinations of exemplary embodiments in whole or in part. 
     The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. 
     Referring now to the appended drawings,  FIG. 1  shows an exemplary system infrastructure of communicatively coupled thin client(s), markup server(s), and thick client(s). In general,  FIG. 1  depicts thin client(s)  300 , markup server(s)  200 , and thick client(s)  400 , all connected via network  100 . 
     Thick client  400  may be implemented in a computing system consistent with or similar to that depicted in  FIG. 9 . Notably, the computing system in which the thick client  400  is implemented may provide rich functionality independent of a connected server. For example, thick client  400  may be implemented in a full-featured computer including a local, nonvolatile data storage (e.g., hard drive). In one embodiment, thick client  400  may be a computer with a software application installed thereon (e.g., a native application) to enable document markup display and modification utilizing native markup objects (e.g., thick client application  410  in  FIG. 2 ). Thick client  400  may be connected to a network  100 , which may be the Internet, via a wired or wireless connection, and may be in communication with markup server(s)  200  via the network  50 . In the present disclosure, a computer that performs document markup display and modification discussed herein using a native application developed for that purpose (i.e., an application that is developed for document markup display and modification and installed locally) may be referred to as thick client  400 . Further, a computer that performs document markup display and modification discussed herein without such a native or locally-installed application may be referred to as thin client  300 , which will be explained in greater detail below. 
     Thin client  300  may also be implemented in a computing system consistent with or similar to that depicted in  FIG. 9 . However, in contrast to thick client  400 , thin client  300  may be implemented in a lightweight computer optimized for establishing a network connection with a server-based computing environment, and may rely heavily or partially on network servers to fulfill a significant part of resource requirement. For example, the computing system in which the thin client  300  is implemented may be a desktop terminal that has no local, nonvolatile data storage (e.g., hard drive). In some embodiments, thin client  300  may be implemented in a full-featured computer, similar to that of thick client  400 , but may not include a separate installation of a software application (i.e., may not include a native application) for document markup display and modification. In other words, thin client  300  may be a full-featured computer that may rely heavily or partially on one or more network servers (i.e., not on a local software application) to perform document markup display and modification contemplated in the present disclosure, without requiring installation of a native application developed for that purpose. Thus, functions related to document markup display and modification that utilize cross-compatible objects, which will be described in greater detail below, may be performed by thin client  300 , and server-based components can be leveraged to handle more resource-intensive tasks such as, for example, processing of PDF data (i.e., native data). In some embodiments, thin client  300  may be a computer, either full-featured or lightweight, that may access document markup display and modification capability via a web-based application. For example, a web-based application may be a client-server computer program which a client may run in a web browser. Thus, using techniques discussed herein, a user may be able to view, create and/or modify markups overlaying a base image/text layer without needing to install software having markup features natively. 
     Server(s) connected with the thin client  300  may perform various functions, e.g., executing software applications, running logic, storing data, etc., and take on the processing load of the thin client  300 . As explained above, thin client  300  may be a computer configured to execute a web browser but might not require a separate installation of a software application for document markup display and modification of the present disclosure (i.e., a web-based application). Thin client  300  may be connected to a network  100  via a wired or wireless connection, and may be in communication with markup server(s)  200  via the network  100 . 
     Thin client(s)  300 , markup server(s)  200 , and thick client(s)  400  may all be connected to network  100 , and may be in communication with one another via the network  100 . Data communication between thin client(s)  300 , markup server(s)  200 , and thick client(s)  400  (e.g., transmission of cross-compatible markup objects and/or native markup objects described below) may be performed utilizing a software library or a communication framework that may allow client-to-server (and vice versa) communications, and/or may allow remote procedure calls. 
     Network connections may be Internet Protocol Suite-compliant with a Transmission Control Protocol (TCP) component as well as a User Datagram Protocol (UDP) component. Depending on the needs of the services involved, the more reliable and ordered (albeit slower) delivery of data possible through a TCP connection may be more appropriate, or the faster but more unreliable delivery of data through a UDP connection may be more appropriate. Although any network modality may be utilized to transfer data among thin client(s)  300 , markup server(s)  200 , and thick client(s)  400 , it will be appreciated that certain improvements may be realized if the protocol selection is tailored to the particular needs. Where an embodiment contemplates such a selection, those will be particularly noted. Along these lines, the specific network topology is presented by way of example only, however, and any other type of arrangement may be substituted. 
       FIG. 2  shows an exemplary embodiment of a document markup synchronization system, according to one aspect of the present disclosure. In general,  FIG. 2  depicts a master markup server  230 , thin client applications  370 A and  370 B, markup libraries  390 A and  390 B, a markup translation server  250 , and a thick client application  410 . In one embodiment, master markup server  230  and markup translation server  250  may be instances of markup server(s)  200 , thin client applications  370 A and  370 B may be instances of thin client(s)  300 , and thick client application  410  may be an instance of thick client(s)  400 . 
     Master markup server  230  may be part of the server-computing environment, i.e., markup server(s)  200 , discussed above in reference to  FIG. 1 . For example, master markup server  230  may be one of the markup servers  200 , or may comprise multiple markup servers  200  together configured to perform functions of the master markup server  230 . Master markup server  230  may be in communication with the various components depicted in  FIG. 2  (i.e., thin client applications  370 A and  370 B, markup translation server  250 ) via network  100 . Master markup server  230  may receive cross-compatible markup objects from the thin client applications  370 A and  370 B (or the thin observer agents  374 A and  374 B thereof) and store the cross-compatible markup objects in a master database. Particularly, master markup server  230  may receive a cross-compatible markup object from a thin client application  370 A, store the cross-compatible markup object in a master database, and transmit the cross-compatible markup object to a thin client application  370 B. This way, master markup server  230  enables real-time, lightweight markup collaboration among a plurality of thin clients  300 . The transmission of the cross-compatible markup objects between the master markup server  230  and thin client applications  370 A and  370 B may be performed using, for example, TCP/IP protocol. In one embodiment, the transmission of the cross-compatible markup objects from the master markup server  230  to a thin client application  370 A or  370 B may occur in real-time using WebSockets. 
     Thin client applications  370 A and  370 B may be implemented on thin client(s)  300  discussed above in reference to  FIG. 1 . Thin client applications  370 A and  370 B may comprise the same or largely the same components to perform markup modification and collaboration session functionalities. Therefore, for the sake of brevity, the relevant components in the thin client applications  370 A and  370 B will be described with respect to the thin client application  370 A only. In one embodiment, thin client application  370 A, may comprise a web-based document markup application  372 A and a thin observer agent  374 A. As will be discussed in greater detail below, the web-based document markup application  372 A may be a web-based document reviewing/editing software application which enables a user to locate a document from a remote storage, open and make modifications to the document (e.g., add, remove, or modify drawings, annotations, markups, etc.), save the modified document in a remote storage, delete the document, collaborate with other users (i.e., users on remote devices, e.g., thin client(s)  300 ) synchronously or asynchronously to review/edit the document, etc. In one embodiment, the web-based document markup application  372 A may be a PDF document reviewing/editing software application. However, in other embodiments, the web-based document markup application  372 A may be a document reviewing/editing software application also compatible with other types of documents such as, e.g., word processing document, CAD drawings, etc. The web-based document markup application  372 A may be provided as software as a service (SaaS). Thin observer agent  374 A may be a software module that subscribes to events occurring in the web-based document markup application  372 A, and may be notified of the events as they occur. The types of events that occur in the web-based document markup application  372 A and get reported to the thin observer agent  374 A may include, but might not be limited to, an addition, modification, deletion, and/or movement of a markup in the web-based document markup application  372 A. In response to receiving a notification indicating an event associated with a markup, thin observer agent  374 A may extract a cross-compatible markup object associated with the markup and transmit the cross-compatible markup object to the master markup server  230 . 
     As alluded to above, thin client application  370 A may be an application that is implemented on a thin client  300 , and may comprise a web-based document markup application  372 A. For example, thin client application  370 A may be a web browser installed on a thin client  300 , which provides a platform for the web-based document markup application  372 A to run. Although  FIG. 2  shows the web-based document markup application  372 A and the thin observer agent  374 A enclosed within the thin client application  370 A, most of the application logic and data storage for the web-based document markup application  372 A may be housed and carried out in a server-computing environment, i.e., markup server(s)  200 , discussed above in reference to  FIG. 1 , and the web-based document markup application  372 A may be accessed and provided on the thin client  300  by using a web browser. For example, thin client application  370 A may be a web browser (e.g., JavaScript-enabled web browser) configured to display document markup modifications using cross-compatible markup objects received from the master markup server  230 . As alluded to above, the actual application logic enabling the functionalities of the web-based document application  372 A and the thin observer agent  374 A may be at least partially stored and performed at a back-end system, such as the master markup server  230 . Accordingly, in one embodiment, thin client application  370 A may be an application installed on a thin client  300 , such as a web browser, configured to interpret the cross-compatible, or browser-friendly, markup objects received from the master markup server  230  and to run the web-based document markup application  372 A within the browser. Because at least some of the processing takes place at the back-end server(s), the web-based document markup application  372 A may also be referred to as a server-based document markup application in the present disclosure. In some embodiments, the server-based document markup application may be accessed using means different from a web-browser. For example, the server-based document markup application may also be accessed and provided on various types of devices, including but not limited to, mobile phones, tablets, gaming devices, Internet-of-Things (loT) devices, etc., using an application built on a common application platform such as, e.g., Universal Windows Platform (UWP). 
     Markup library  390 A may be a shared markup rendering library coupled to the thin client application  370 A, such that the web-based document markup application  372 A may render and display the cross-compatible markup objects across various types of devices using the bindings stored in the markup library  390 A. More specifically, markup library  390 A may comprise a cross platform software developer&#39;s kit (SDK) for rendering and mutating markups in the web-based (i.e., server-based) document markup application  372 A accessed by a variety of devices. For example, markup library  390 A may be a cross-platform markup rendering library written in the Rust programming language, with bindings for HTML5 Canvas using WebAssembly and/or iOS. 
     Master markup server  230  may transmit the cross-compatible markup objects to another markup server(s)  200 . For example, master markup server  230  may transmit the cross-compatible markup objects to markup translation server  250  for further processing. The transmission of the cross-compatible markup objects from the master markup server  230  to the markup translation server  250  may be performed using, for example, TCP/IP protocol, in order to “push” the cross-compatible markup objects to the markup translation server  250  periodically, upon trigger events, and/or as they become available. 
     Markup translation server  250  may also be part of the server-computing environment, i.e., markup server(s)  200 , discussed above in reference to  FIG. 1 . For example, markup translation server  250  may be one of the markup servers  200 , or may comprise multiple markup servers  200  together configured to perform functions of the markup translation server  250 . Markup translation server  250  may comprise a thin-to-thick translation logic  254 . As will be further elaborated below, markup translation server  250  may receive cross-compatible markup objects from the master markup server  230 , and may use the thin-to-thick translation logic  254  to translate the cross-compatible markup objects to native markup objects. The native markup objects may then be stored in a local storage or a remote storage in communication with the markup translation server  250 . The native markup objects may be available for consumption by the thick client application  410 . The native markup objects may be transmitted to the thick client application  410  using, for example, TCP/IP protocol. The transmission may occur periodically, upon trigger events, as the native markup objects become available, and/or in response to requests generated by the thick client application  410 . 
     Thick client application  410  may be a software application installed and executed on a thick client  400  discussed above in reference to  FIG. 1 . Accordingly, most or the majority of the processing required by the thick client application  410  may be performed at the client side (i.e., thick client  400 ) and may involve only aperiodic connection to a server computing environment (e.g., for archival or data communication purposes). For example, the thick client application  410  may run on a windowing system, and accordingly has a number of interface elements that are common to such applications. Each of thick clients  400  may have a copy of the thick client application  410  installed thereon. The copies of the thick client application  410  need not be identical, however, and some thick clients  400  may have a copy with a differing set of functionalities than another such as with trial versions, reader-only versions, and so forth. In some embodiments, some of the processing required by the thick client application  410  may be performed at the server side. 
     Thick client application  410  may comprise a document markup application  412 . As will be discussed in greater detail below, the document markup application  412  may be a document reviewing/editing software application which enables a user to locate a document from a local or remote storage, open and make modifications to the document (e.g., add, remove, or modify drawings, annotations, markups, etc.), save the modified document in a local or remote storage, delete the document, collaborate with other users (i.e., users on remote devices, e.g., thick client(s)  100  and/or thin client(s)  300 ) synchronously or asynchronously to review/edit the document, etc. In one embodiment, the document markup application  412  may be a PDF document reviewing/editing software application. However, in other embodiments, the document markup application  412  may be a document reviewing/editing software application also compatible with other types of documents such as, e.g., word processing document, CAD drawings, etc. 
     As alluded to above, thick client application  410  may receive native markup objects from the markup translation server  250 , after cross-compatible objects have been converted to native markup objects at the markup translation server  250 . Therefore, while the master markup server  230  enables real-time, lightweight collaboration among thin clients  300  using cross-compatible markup objects, the markup translation server  250  may publish the markup objects being modified at one or more thin clients  300  to native markup objects, such that any device with a conforming document viewing/editing software (i.e., software configured to render native markup objects), including thick clients  400 , may also be able to consume and display those markups. In one embodiment, upon user selection, a thick client application  410  may reach out to the markup translation server  250  for any markups that have been modified or newly created with respect to a particular document. In some embodiments, a thick client application  410  may receive native markup objects periodically. In some embodiments, a thick client application  410  may receive native markup objects incrementally, meaning the thick client application  410  may be configured to fetch native markup objects from the markup translation server  250  when there are any changes in markups associated with a particular document. 
     In one embodiment and as will be discussed in greater detail below, a cross-compatible markup object may be a JavaScript Object Notation (JSON) object describing a markup modified by a user of a web-based document markup application  372 A or  372 B. In contrast, a native markup object may be a PDF dictionary object corresponding to such a cross-compatible markup object describing the modified markup (i.e., a PDF dictionary object translated from the JSON object). Therefore, a cross-compatible markup object may be more consumable, and more easily and quickly processed (e.g., less processing-intensive) by a web-based application than a native markup object. Cross-compatible markup objects may be used to synchronize displays across thin clients  300  during a markup collaboration session. Native markup objects may be created by translating the cross-compatible markup objects, but the native markup objects might not be used to synchronize displays across thin clients  300 , as web-based document markup applications  372 A and  372 B of thin clients  300  may be configured to use cross-compatible markup objects rather than native markup objects, for the reasons discussed above (e.g., more consumable, less processing-intensive, etc. for web-based applications). Instead, native markup objects may be archived or stored in a document store, and be available for rendering by thick clients  400  using, for example, native applications that are developed for markup display/modification and installed locally at individual thick clients  400 . 
     PDF lacks a consistent string encoding mechanism such as UTF-8. As known to a person of ordinary skill in the relevant art, UTF-8 is a variable width character encoding capable of encoding all 1,112,064 valid code points in Unicode using one to four 8-bit bytes, designed for backward compatibility with American Standard Code for Information Interchange (ASCII). PDF has a myriad of string encodings, and to properly account for all variations and full Unicode support requires significant PDF expertise. In contrast, the JSON object simply uses UTF-8, which is a format that is much more consumable by various device types of varying characteristics and processing capacities. 
     To illustrate the complexity involved with processing a PDF dictionary object, the following example is provided. “Blue” is encoded in a PDF string as (BI\374e). The \374 character is an octally encoded index into the “PDF Encoding” which is a character set specific to PDF. From there the glyph name “udieresis” can be determined from a lookup table. The actual Unicode code points can then be determined and then finally the string can be encoded as UTF-8. It would be undesirable to duplicate this type of logic at thin clients  300 , which might have limited processing and/or rendering power and substantial reliance on servers compared to thick clients  400 , or which might be better served by saving processing and/or rendering power by making markup display/modification process more efficient. Further, it would be undesirable to perform markup display and modification using PDF dictionary objects (e.g., native markup objects) at thin clients  300 , which might be better-suited or designed to run web-based applications (e.g., web-based document markup applications  372 A and  372 B) in lieu of locally-installed, native applications. 
     Another complexity to PDF dictionary objects is that for certain markup types, the PDF Dictionary objects reference other external PDF Dictionary objects that are “Resources.” For instance, markup representations for stamps and images, and for markups that contain hatch patterns and/or are measurement-based, all have such resources. To render native markup objects, all of these resource types might need to be accounted for. For example, image markups may need to have the image extracted. For stamps (of which the appearance may be arbitrary PDF content), a set of resources may need to be repackaged into a standalone PDF file, and a rasterized version of that PDF may also need to be saved. PDF supports a vast number of image types and some at this point are only supported within PDF (e.g., JBIG2 and Jpeg2000 in particular) which accounts for some of the complexity. A JSON object representative of a markup or modification thereof (e.g., a cross-compatible markup object) may not require these steps and may instead result in substantial reduction in computational load and processing time when used in conjunction with a web-based application (e.g., web-based document markup applications  372 A and  372 B). 
     It should be noted that, although thick client application  410 , master markup server  230 , markup translation server  250 , thin client applications  370 A and  370 B, and markup libraries  390 A and  390 B are shown as separate entities in  FIG. 2 , all or a portion of these components (and the steps performed thereof) may be implemented in a single computing device consistent with or similar to that depicted in  FIG. 9 . For example, in one embodiment, master markup server  230  and markup translation server  250  may be implemented on a single computing device. In another embodiment, thick client application  410 , master markup server  230 , and markup translation server  250  may be implemented on a single computing device. In yet another embodiment, thin client application  370 A and markup library  390 A may be implemented on a single computing device, and thin client application  370 B and markup library  390 B may be implemented on a single computing device. In yet another embodiment, thick client application  410 , master markup server  230 , markup translation server  250 , thin client applications  370 A and  370 B, and markup libraries  390 A and  390 B may indeed be implemented separately on their respective computing devices, as depicted in  FIG. 2 . In other words, one of ordinary skill will recognize that the configurations specifically discussed herein regarding the arrangement of the components depicted in  FIG. 2  are merely exemplary, and it would be obvious to a person of ordinary skill in the relevant art that different combinations of components may be implemented on a single or multiple computing devices. 
     With continuing reference to  FIG. 2 , the web-based document markup applications  372 A and  372 B may enable users of thin clients  300  to collaborate in a real-time document markup modification session. For example, the user of the thin client application  370 A may invite the user of the thin client application  370 B to a document markup modification session, using the web-based document markup application  372 A. The invitation may be sent by an email, a text message, a chat message, etc. The user of the thin client application  370 B may join the document markup modification session by accepting the invitation, for example, by clicking a link in the invitation or by starting the web-based document markup application  372 B and inputting a session identifier and/or a password provided in the invitation. Any now known or later developed forms of invitation and authorization process may be used to invite and authorize access to a document markup modification session. Further, the user of the thin client application  370 A may set permissions, so that the user of the thin client application  370 B may have limited or full access/privileges to document markups and/or modifications thereof. For example, the permissions may specify whether the invited user is authorized to view, add, modify, delete, upload, and/or download certain markups. Once users of the thin client application  370 A and the thin client application  370 B are in-session, the users may collaboratively view, add, modify, and/or delete the document markups (any of these actions will be referred to as a “markup modification” throughout this disclosure) within their respective applications (i.e., web-based document markup application  372 A and web-based document markup application  372 B). The markup modification by a user may be monitored and reported to the master markup server  230  by an observer agent (i.e., thin observer agent  374 A or thin observer agent  374 B), and may further be processed by the master markup server  230  prior to being propagated to the web-based document markup application of the other user. The process of propagating the markup modification may be completed synchronously or substantially synchronously, so that the user of the receiving web-based document markup application may see the changed markup in real-time. 
     More particularly, the markup modification may initially be represented by a cross-compatible markup object (i.e., a browser-friendly markup object), which may be the format used by web-based markup applications  370 A- 370 B. In the event that there are users within a markup modification session who are using the same type of client application, translation of the markup object may be unnecessary and the initial representation of the markup modification may be transmitted without being translated. Therefore, in a real-time lightweight collaboration session that only involves thin clients  300 , it may be unnecessary to translate the initial representation of the markup modification to a target representation (e.g., cross-compatible markup objects to native markup objects), as the web-based document markup applications  372 A- 372 B may both be configured to render cross-compatible markup objects. The present disclosure will primarily discuss such thin-to-thin client scenarios, with an option to publish native markup objects for consumption by thick clients as needed. Methods and systems for real-time markup modification collaboration across different client types (i.e., thick-to-thin or thin-to-thick client scenarios) are disclosed in a related U.S. Non-Provisional application Ser. No. 16/239,044, which is incorporated herein by reference in its entirety. 
       FIG. 3  shows exemplary graphical user interfaces (GUls) of thin client applications during a markup modification session. In general,  FIG. 3  depicts a thin client application  370 A, a markup  70 A applied within the thin client application  370 A, a thin client application  370 B, and a markup  70 B displayed within the thin client application  370 B. 
     In the present disclosure, a markup modification session may be generally understood to be an interactive exchange of markups or modifications thereof among thin clients  300  (e.g., thin client  300 A and thin client  300 B in  FIG. 3 ), which are participants in that markup modification session. The markup modification session may be defined by one or more markups that are reviewed and/or manipulated, and by the participants involved. Additionally, each markup modification session may have associated therewith permissions as to which participants can join that markup modification session, and the identity of the participant initiating that markup modification session. In one embodiment, the participants can join simultaneously, or in a synchronous markup modification session, to work on the markups in real-time. In other embodiments, the markup modification session may be asynchronous because it may not be necessary for each of the participants to join at the same time to work on the markups, and for providing an offline mode in case of intermittent network connectivity, where a participant may still work on the markups without being connected to the network. Under such a circumstance, the modifications made while offline may be uploaded once the network connectivity is restored. Various embodiments of the present disclosure contemplate features that enable such synchronous/asynchronous markup modification sessions. 
     For example, in a synchronous markup modification session, when a markup  70 A is modified by a user of the thin client application  370 A, the markup modification may be propagated to the thin client application  370 B in real-time and the modified markup is displayed as the markup  70 B within the thin client application  370 B. Conversely, when the markup  70 B is modified by the user of the thin client application  370 B, the markup modification may be propagated to the thin client application  370 A in real-time and the modified markup is displayed as the markup  70 A within the thin client application  370 A. Notably, attributes of the markup  70 A (e.g., location, size, color, rotation, markup type, text, etc.) may be identical to those of the markup  70 B. The modification may include, but might not be limited to, addition, deletion, movement, replacement (with a different markup), resizing, change of orientation/rotation, text addition/modification, color modification, or any other modification that may be represented at least in part by the cross-compatible markup object. 
     Various functions performed by the components depicted in  FIG. 2  will now be described. It should be appreciated that the described methods are merely exemplary. In some embodiments, the methods may include a number of additional or alternative steps, and in some embodiments, one or more of the described steps may be omitted. Any described step may be omitted or modified, or other steps added, as long as the intended functionality of the document markup synchronization system remains substantially unaltered. Further, although a certain order is described or implied in the described methods, in general, the steps of the described methods need not be performed in the illustrated and described order. Further, the described methods may be incorporated into a more comprehensive procedure or process having additional functionality not described herein. 
       FIG. 4  is a flowchart illustrating an exemplary method of extracting and transmitting a cross-compatible markup object, according to one aspect of the present disclosure. In one embodiment, method  405  may be performed by a thin observer agent  374 A at a thin client  300  (i.e., thin client application  370 A thereof). First, at step  410 , the thin observer agent  374 A may subscribe to events occurring in the web-based document markup application  372 A. The events may comprise markup modification events. At step  430 , in response to an event occurring in the web-based document markup application  372 A, the thin observer agent  374 A may receive an event notification indicating a change to a markup or an addition of a markup (i.e., indicating a markup modification). At step  450 , in response to receiving the notification, the thin observer agent  374 A may extract a markup object associated with the changed or added markup. In some embodiments, the thin observer agent  374 A may have access to in-memory markup representation (e.g., in-memory JavaScript Object Notation (JSON) representation). In response to being notified of the markup modification event, the thin observer agent  374 A may access the in-memory markup representation, and extract the cross-compatible markup object associated with the modified markup. In one embodiment, the cross-compatible markup may be a JSON object representing the modified markup. At step  470 , the thin observer agent  374 A may compress the cross-compatible markup object, and at step  490 , may transmit the compressed cross-compatible markup object to a master markup server  230 . In some embodiments, the thin observer agent  374 A may transmit the cross-compatible markup object directly to another thin client  300 , e.g., thin client application  370 B. In some embodiments, the cross-compatible markup object may not be compressed prior to being transmitted. In some embodiments, data transmission between the thin observer agent  374 A and the master markup server  230  may take place over the network  100 . However, in other embodiments, as discussed above in reference to  FIG. 2 , data transmission between the thin observer agent  374 A and the master markup server  230  may be between components of a single computing device. Further, in some embodiments, the master markup server  230  and the markup translation server  250  may also be implemented in a single computing device (i.e., a single server). Therefore, any subsequent transmission of the cross-compatible markup object between the master markup server  230  and the markup translation server  250  may actually be a transmission between components of a single computing device. 
       FIG. 5  is a flowchart illustrating an exemplary method of transmitting a cross-compatible object from a master markup server  230  to a thin client  300  (e.g., thin client application  370 B). In one embodiment, method  500  may be performed by master markup server  230 . At step  520 , the master markup server  230  may receive a cross-compatible object from a thin client  300  such as, for example, a thin observer agent  374 A. In the event that the markup object has been compressed by the sending component (i.e., thin client application  370 A), the received cross-compatible markup object may be decompressed by the master markup server  230 . At step  540 , the master markup server  230  may store the cross-compatible object in a master database. At step  560 , the master markup server  230  may then transmit the cross-compatible object to another thin client  300  such as, for example, a thin observer agent  374 B. 
     The master markup server  230  may perform other functions in relation to cross-compatible markup objects. As alluded to above, the user of the thin client application  370 A may initiate a markup collaboration session, invite one or more other users who may also be on thin client devices running respective thin client applications (e.g., thin client application  370 B). The user of the thin client application  370 A may also set permissions for each invited user. For example, the user of the thin client application  370 B may have limited or full access/privileges to document markups and/or modifications thereof. For example, the permissions may specify whether the invited user is authorized to view, add, modify, delete, upload, and/or download certain markups. Further, the user of the thin client application  370 A may be able to specify permissions for the invited users with respect to each other. For the purposes of illustration only, it will be assumed there are three users in a collaboration session: user A who started the collaboration session, and user B and user C who are invitees. In addition to setting the overall permissions for user B and user C, such as whether they are authorized to view, add, modify, delete, upload, and/or download certain markups, user A may also specify what user B can see or do with respect to any markup modification performed by user C, and vice versa. For example, user A may specify whether user B is permitted to view markup modification performed by user C, and whether user C is permitted to view markup modification performed by user B during the collaboration session. Further, user A may be able to specify, if user B is permitted to view markup modification performed by user C, whether user B can also add, modify, or delete markups being manipulated by user C. Therefore, the initiator of the collaboration session may be able to set general permissions for the invited users (i.e., permissions with respect to all markups involved during collaboration session), and/or may also be able to set more fine-grained permissions for each invited user with respect to one or more other invited users (i.e., permissions with respect to markups created/manipulated by other invited user(s) during collaboration session). In one embodiment, permission configuration may be role-based and/or group-based. Additionally or alternatively, permission levels may be assigned to each individual independently (i.e., user-based). To facilitate the permissioning mechanism, the master markup server  230  may receive such permission settings from a thin client application (e.g., thin client application  370 A) and apply them to thin client applications of the invited users (e.g., thin client application  370 B), so that the invited users may be allowed a level of access that was predefined by the user who started the collaboration session. 
       FIG. 6  is a flowchart illustrating an exemplary method of translating a cross-compatible object to a native markup object. Notably, method  600  may be performed by markup translation server  250 . At step  620 , the markup translation server  250  may receive a cross-compatible markup object from master markup server  230 . In some embodiments, the markup translation server  250  may receive the cross-compatible markup object directly from the thin client application  370 A, bypassing the master markup server  230 . In the event that the markup object has been compressed by the sending component (i.e., master markup server  230  or thin client application  370 A), the received cross-compatible markup object may be decompressed by the markup translation server  250 . At step  640 , the markup translation server  250  may translate the cross-compatible markup object to a native markup object.  FIG. 7  illustrates an exemplary cross-compatible markup object  70 A and a corresponding exemplary native markup object  10 A. In one embodiment, a cross-compatible markup object may be a JSON object describing the markup modified by the user of the web-based document markup application  372 A and a native markup object may be a PDF dictionary object corresponding to the cross-compatible markup object describing the modified markup (i.e., a PDF dictionary object translated from the JSON object). The format associated with the cross-compatible markup object may be more browser/web-compatible (i.e., substantially less processing intensive in a browser/web environment) than the PDF dictionary markup object. In  FIG. 7 , the exemplary cross-compatible markup object  70 A (i.e., JSON object representing a “circle” markup applied to a PDF) and the corresponding native markup object  10 A (i.e., a PDF dictionary object converted from the JSON object) are shown side-by-side. 
     Referring back to  FIG. 6 , at step  660 , the markup translation server  250  may store the native markup object in a document store. The document store may be a storage resident in the markup translation server  250 , or a storage remotely located from the markup translation server  250 . As alluded to above, thick client application  410  may retrieve the native markup object to render the modified markup within the document markup application  412 , as needed. In some embodiments, native markup objects may be transmitted to the thick client application  410  as they become available at the markup translation server  250 , or if the markups represented by the native markup objects have not been committed yet in the thick client application  410 . 
       FIG. 8  is a system flowchart illustrating an exemplary method of synchronizing a document markup modification across a plurality of thin client devices. In particular,  FIG. 8  illustrates a method of propagating a document markup modification made using a thin client application  370 A (or the web-based document markup application  372 A thereof) to a thin client application  370 B (or the web-based document markup application  372 B thereof). 
     At step  810 , thin observer agent  374 A may subscribe to events occurring in the web-based document markup application  372 A. The events may comprise markup modification events. At step  820 , in response to an event occurring in the web-based document markup application  372 A, the thin observer agent  374 A may receive an event notification indicating a change to a markup or an addition of a markup (i.e., indicating a markup modification). At step  830 , in response to receiving the notification, the thin observer agent  374 A may extract a cross-compatible markup object associated with the changed or added markup. Then, at step  840 , the thin observer agent  374 A may transmit the cross-compatible markup object to a master markup server  230 . The cross-compatible markup object may be compressed prior to transmission. 
     With continuing reference to  FIG. 8 , at step  850 , the master markup server  230  may receive the cross-compatible markup object from the thin client application  370 A. As alluded to above, the master markup server  230  may also receive user permission settings from the thin client application  370 A. The received cross-compatible markup object may be decompressed, if it was compressed prior to transmission. At step  860 , the master markup server  230  may store the cross-compatible markup object in a master database. Additionally, the master markup server  230  may also store the user permission settings in the master database. At step  870 , the master markup server  230  may transmit the cross-compatible markup object to a thin client application  370 B (or the web-based document markup application  372 B thereof) in a compressed, or non-compressed format. Additionally, the master markup server  230  may transmit the cross-compatible markup object to a markup translation server  250  for translation to a native markup object. Further, in some embodiments, the master markup server  230  may transmit the user permission settings to the thin client application  370 B. 
     At step  880 , the thin client application  370 B may receive the cross-compatible markup object from the master markup server  230 , along with any other data such as the user permission settings. The cross-compatible markup object may be decompressed, if it was compressed prior to transmission. At step  890 , the thin client application  370 B may render the cross-compatible markup object in the web-based document markup application  372 B. In some embodiments, the cross-compatible markup object may be rendered within the web-based document markup application  372 B in accordance with the user permission settings received from the master markup server  230 . 
     Embodiments of the present disclosure concerning synchronizing a document markup modification across a plurality of thin client devices addresses the drawbacks of the prior approaches, using some of the techniques discussed above. In general, the embodiments of the present disclosure have at least the following distinguishable features that lead to significant technical improvements:
         1) Renders markup objects across various types of thin client devices without duplicating markup interpretation/translation logic on each of those devices, by using bindings stored in a markup library.   2) Open format markups suitable for consumption by a variety of computing platforms (e.g., thick/thin clients, third party applications, etc.).   3) Enables markups to flow throughout the document markup modification ecosystem, regardless of the clients or services producing or consuming the markup information.       

     Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining”, “analyzing” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities into other data similarly represented as physical quantities. 
     In a similar manner, the term “processor” may refer to any device or portion of a device that processes electronic data, e.g., from registers and/or memory to transform that electronic data into other electronic data that, e.g., may be stored in registers and/or memory. A “computer,” a “computing machine,” a “computing platform,” a “computing device,” or a “server” may include one or more processors. 
       FIG. 9  illustrates an implementation of a computer system designated  900 . The computer system  900  can include a set of instructions that can be executed to cause the computer system  900  to perform any one or more of the methods or computer based functions disclosed herein. The computer system  900  may operate as a standalone device or may be connected, e.g., using a network, to other computer systems or peripheral devices. 
     In a networked deployment, the computer system  900  may operate in the capacity of a server or as a client user computer in a server-client user network environment, or as a peer computer system in a peer-to-peer (or distributed) network environment. The computer system  900  can also be implemented as or incorporated into various devices, such as a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile device, a palmtop computer, a laptop computer, a desktop computer, a communications device, a wireless telephone, a land-line telephone, a control system, a camera, a scanner, a facsimile machine, a printer, a pager, a personal trusted device, a web appliance, a network router, switch or bridge, or any other machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. In a particular implementation, the computer system  900  can be implemented using electronic devices that provide voice, video, or data communication. Further, while a single computer system  900  is illustrated, the term “system” shall also be taken to include any collection of systems or sub-systems that individually or jointly execute a set, or multiple sets, of instructions to perform one or more computer functions. 
     As illustrated in  FIG. 9 , the computer system  900  may include a processor  902 , e.g., a central processing unit (CPU), a graphics processing unit (GPU), or both. The processor  902  may be a component in a variety of systems. For example, the processor  902  may be part of a standard personal computer or a workstation. The processor  902  may be one or more general processors, digital signal processors, application specific integrated circuits, field programmable gate arrays, servers, networks, digital circuits, analog circuits, combinations thereof, or other now known or later developed devices for analyzing and processing data. The processor  902  may implement a software program, such as code generated manually (i.e., programmed). 
     The computer system  900  may include a memory  904  that can communicate via a bus  908 . The memory  904  may be a main memory, a static memory, or a dynamic memory. The memory  904  may include, but is not limited to computer readable storage media such as various types of volatile and non-volatile storage media, including but not limited to random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media and the like. In one implementation, the memory  904  includes a cache or random-access memory for the processor  902 . In alternative implementations, the memory  904  is separate from the processor  902 , such as a cache memory of a processor, the system memory, or other memory. The memory  904  may be an external storage device or database for storing data. Examples include a hard drive, compact disc (“CD”), digital video disc (“DVD”), memory card, memory stick, floppy disc, universal serial bus (“USB”) memory device, or any other device operative to store data. The memory  904  is operable to store instructions executable by the processor  902 . The functions, acts or tasks illustrated in the figures or described herein may be performed by the programmed processor  902  executing the instructions stored in the memory  904 . The functions, acts or tasks are independent of the particular type of instructions set, storage media, processor or processing strategy and may be performed by software, hardware, integrated circuits, firm-ware, micro-code and the like, operating alone or in combination. Likewise, processing strategies may include multiprocessing, multitasking, parallel processing and the like. 
     As shown, the computer system  900  may further include a display  910 , such as a liquid crystal display (LCD), an organic light emitting diode (OLED), a flat panel display, a solid-state display, a cathode ray tube (CRT), a projector, a printer or other now known or later developed display device for outputting determined information. The display  910  may act as an interface for the user to see the functioning of the processor  902 , or specifically as an interface with the software stored in the memory  904  or in the drive unit  906 . 
     Additionally or alternatively, the computer system  900  may include an input device  912  configured to allow a user to interact with any of the components of system  900 . The input device  912  may be a number pad, a keyboard, or a cursor control device, such as a mouse, or a joystick, touch screen display, remote control, or any other device operative to interact with the computer system  900 . 
     The computer system  900  may also or alternatively include a disk or optical drive unit  906 . The disk drive unit  906  may include a computer-readable medium  922  in which one or more sets of instructions  924 , e.g. software, can be embedded. Further, the instructions  924  may embody one or more of the methods or logic as described herein. The instructions  924  may reside completely or partially within the memory  904  and/or within the processor  902  during execution by the computer system  900 . The memory  904  and the processor  902  also may include computer-readable media as discussed above. 
     In some systems, a computer-readable medium  922  includes instructions  924  or receives and executes instructions  924  responsive to a propagated signal so that a device connected to a network  100  can communicate voice, video, audio, images, or any other data over the network  100 . Further, the instructions  924  may be transmitted or received over the network  100  via a communication port or interface  920 , and/or using a bus  908 . The communication port or interface  920  may be a part of the processor  902  or may be a separate component. The communication port  920  may be created in software or may be a physical connection in hardware. The communication port  920  may be configured to connect with a network  100 , external media, the display  910 , or any other components in computer system  900 , or combinations thereof. The connection with the network  100  may be a physical connection, such as a wired Ethernet connection or may be established wirelessly as discussed below. Likewise, the additional connections with other components of the computer system  900  may be physical connections or may be established wirelessly. The network  100  may alternatively be directly connected to the bus  808 . 
     While the computer-readable medium  922  is shown to be a single medium, the term “computer-readable medium” may include a single medium or multiple media, such as a centralized or distributed database, and/or associated caches and servers that store one or more sets of instructions. The term “computer-readable medium” may also include any medium that is capable of storing, encoding, or carrying a set of instructions for execution by a processor or that cause a computer system to perform any one or more of the methods or operations disclosed herein. The computer-readable medium  922  may be non-transitory, and may be tangible. 
     The computer-readable medium  922  can include a solid-state memory such as a memory card or other package that houses one or more non-volatile read-only memories. The computer-readable medium  922  can be a random-access memory or other volatile re-writable memory. Additionally or alternatively, the computer-readable medium  922  can include a magneto-optical or optical medium, such as a disk or tapes or other storage device to capture carrier wave signals such as a signal communicated over a transmission medium. A digital file attachment to an e-mail or other self-contained information archive or set of archives may be considered a distribution medium that is a tangible storage medium. Accordingly, the disclosure is considered to include any one or more of a computer-readable medium or a distribution medium and other equivalents and successor media, in which data or instructions may be stored. 
     In an alternative implementation, dedicated hardware implementations, such as application specific integrated circuits, programmable logic arrays and other hardware devices, can be constructed to implement one or more of the methods described herein. Applications that may include the apparatus and systems of various implementations can broadly include a variety of electronic and computer systems. One or more implementations described herein may implement functions using two or more specific interconnected hardware modules or devices with related control and data signals that can be communicated between and through the modules, or as portions of an application-specific integrated circuit. Accordingly, the present system encompasses software, firmware, and hardware implementations. 
     The computer system  900  may be connected to one or more networks  100 . The network  100  may define one or more networks including wired or wireless networks. The wireless network may be a cellular telephone network, an 802.11, 802.16, 802.20, or WiMax network. Further, such networks may include a public network, such as the Internet, a private network, such as an intranet, or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to TCP/IP based networking protocols. The network  100  may include wide area networks (WAN), such as the Internet, local area networks (LAN), campus area networks, metropolitan area networks, a direct connection such as through a Universal Serial Bus (USB) port, or any other networks that may allow for data communication. The network  100  may be configured to couple one computing device to another computing device to enable communication of data between the devices. The network  100  may generally be enabled to employ any form of machine-readable media for communicating information from one device to another. The network  100  may include communication methods by which information may travel between computing devices. The network  100  may be divided into sub-networks. The sub-networks may allow access to all of the other components connected thereto or the sub-networks may restrict access between the components. The network  100  may be regarded as a public or private network connection and may include, for example, a virtual private network or an encryption or other security mechanism employed over the public Internet, or the like. 
     In accordance with various implementations of the present disclosure, the methods described herein may be implemented by software programs executable by a computer system. Further, in an exemplary, non-limited implementation, implementations can include distributed processing, component/object distributed processing, and parallel processing. Alternatively, virtual computer system processing can be constructed to implement one or more of the methods or functionality as described herein. 
     Although the present specification describes components and functions that may be implemented in particular implementations with reference to particular standards and protocols, the disclosure is not limited to such standards and protocols. For example, standards for Internet and other packet switched network transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) represent examples of the state of the art. Such standards are periodically superseded by faster or more efficient equivalents having essentially the same functions. Accordingly, replacement standards and protocols having the same or similar functions as those disclosed herein are considered equivalents thereof. 
     It will be understood that the steps of methods discussed are performed in one embodiment by an appropriate processor (or processors) of a processing (i.e., computer) system executing instructions (computer-readable code) stored in storage. It will also be understood that the invention is not limited to any particular implementation or programming technique and that the invention may be implemented using any appropriate techniques for implementing the functionality described herein. The invention is not limited to any particular programming language or operating system. 
     It should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. 
     Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. 
     Furthermore, some of the embodiments are described herein as a method or combination of elements of a method that can be implemented by a processor of a computer system or by other means of carrying out the function. Thus, a processor with the necessary instructions for carrying out such a method or element of a method forms a means for carrying out the method or element of a method. Furthermore, an element described herein of an apparatus embodiment is an example of a means for carrying out the function performed by the element for the purpose of carrying out the invention. 
     In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. 
     Similarly, it is to be noticed that the term coupled, when used in the claims, should not be interpreted as being limited to direct connections only. The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression a device A coupled to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Coupled” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. 
     Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as falling within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention. 
     The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other implementations, which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. While various implementations of the disclosure have been described, it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible within the scope of the disclosure. Accordingly, the disclosure is not to be restricted except in light of the attached claims and their equivalents.