Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
  • H04N21/23412—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs for generating or manipulating the scene composition of objects, e.g. MPEG-4 objects
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T13/00—Animation
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T17/00—Three-dimensional [3D] modelling for computer graphics
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
  • H04N21/2343—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements
  • H04N21/234318—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements by decomposing into objects, e.g. MPEG-4 objects
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
  • H04N21/44—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
  • H04N21/44012—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs involving rendering scenes according to scene graphs, e.g. MPEG-4 scene graphs

Definitions

• the present invention relates to techniques for describing graphic animations.
• the invention provides a method for managing graphic scenes, as well as a storage system and a receiver for implementing this method.
• - one is based on a representation in the form of a tree of the spatio-temporal arrangement of graphic objects which allows a fine interaction between objects and graphic sub-objects but requires an intermediate processing before the actual display (ie, screening or "rasterization" according to the English terminology generally used);
• the other approach is based on a frame rendering mode of polygonal shapes, and uses simple primitives which ensure fast rendering.
• the first approach corresponds for example to graphical description formats such as those used by W3C / SVG and MPEG-
• This first approach does not allow optimal graphic rendering. It also induces an additional calculation cost for certain animations which would not require the use of this technique.
• the second approach allows efficient rendering of graphic animations; however, it does not allow fine interaction with the graphic sub-objects making up the graphic animation and rendering depends on the viewing characteristics of the receiver. This second approach corresponds, for example, to graphic formats like SWF from Macromedia or the "display lists" commonly used in 3D visualization by tools like Openlnventor.
• An object of the invention is to propose a technique which makes it possible to overcome the drawbacks of current graphic representation techniques, which suffer either from a lack of interactivity, or from a lack of efficiency in graphic rendering.
• a graphic animation is defined by a set of data describing a content of spatio-temporal arrangement of graphic objects to be displayed, and in that said set comprises for at at least one of these graphic objects of the data describing primitives corresponding to this graphic object, the data describing a space-time arrangement content and the data describing the primitives of graphic objects being stored independently.
• the proposed technique makes it possible in particular, by mixing several levels of vector graphic representation, to save memory space by allowing the use of the graphic representation most suited to a given animation.
• Many graphic representations or animations do not in fact need to be described in the form of composition of simple vector primitives, but can benefit from a representation in the form of a list of lower-level graphic rendering primitives.
• Low-level primitives are for example of the type ⁇ action, polygon, duration ⁇ where the action is the addition, replacement or destruction of a shape described by a polygon with integer coordinates and not vectorial.
• This technique also has the advantage, by playing on different modes of representation, of making it possible to control the performance of the graphic rendering engine and this in particular thanks to a non-systematic use of the space-time arrangement.
• the proposed technique can also easily be integrated into most graphic rendering devices which allow the rendering of vector shapes.
• the storage means comprise server means, capable of transmitting to a remote client data describing a content of space-time arrangement of graphic objects to be displayed and or data describing primitives; - a space-time arrangement content which contains an object defined by independently stored primitives comprises data identifying said data and / or the means in which they are stored;
• data are received which correspond to the content of a space-time arrangement of graphic objects to be displayed, the data thus received from said means are decoded and, when the arrangement which corresponds to this data comprises a graphic object intended to be defined by primitives stored independently, data corresponding to these primitives are received and decoded;
• the primitives corresponding to the data received for said graphic object are directly displayed and in that one implements on the space-time arrangement content a pre-rendering processing before display; the primitives corresponding to the data received for said graphic object are transmitted to a stack of rendering primitives, with the primitives obtained, for the space-time arrangement content, at the output of the pre-rendering processing.
• the invention further relates to a receiver comprising display means, as well as means for receiving and decoding data describing a space-time arrangement content of graphic objects to be displayed, characterized in that it comprises means for receiving and decoding data memorized independently and corresponding to primitives defining at least one graphic object in the content of spatio-temporal arrangement for said object, processing means implementing on all of these data processing allowing 'display the content of space-time arrangement and said primitives. It also proposes a system for implementing the method for managing descriptions of graphic animations intended to be displayed according to one of the preceding claims, characterized in that it comprises means in which the data describing a content of spatio-temporal arrangement and the data describing primitives of graphic objects are stored independently.
• It also provides a signal carrying a set of data defining a spatio-temporal arrangement of graphic objects and sub-objects intended to be displayed, characterized in that this set comprises for at least one graphic object data identifying primitives stored independently e / or data identifying the means in which they are stored.
• the invention also further relates to a method for the decomposition of images of graphic animations intended to be displayed, characterized in that these images are decomposed into a set of data describing a content of spatio-temporal arrangement d graphic objects to be displayed and, for at least one of the graphic objects, in a set of data defining primitives corresponding thereto, the content of space-time arrangement comprising, for said graphic object, data designating the means of storage in which the data defining these primitives of said object are intended to be stored.
• FIG. 1 is a schematic representation illustrating the reception of an initial scene ;
• Figure 2 is a schematic representation illustrating the rendering processing implemented at the receiver shown in Figure 1;
• Figure 3 is a schematic representation illustrating the encoding of an image.
• a receiver R which is for example a mobile telephone which exchanges with at least two external data sources (servers A and B), from which it receives binary data streams describing the scenes and graphic objects intended to be displayed by said receiver R.
• servers A and B external data sources
• the receiver R requests a content of graphic animations at the source which constitutes the server A
• This server A transmits to said receiver R content S (the graphic scene) which describes the space-time arrangement of the graphic objects.
• the receiver R interrogates the server B which, in the information that said receiver R has just received from the server A, is designated as being the particular server in which the graphic primitives P which correspond to the composite object OC in question are referenced.
• These graphic primitives are for example advantageously low-level graphic primitives of the “actions, polygons, duration” type.
• the arrows 3 and 4 in FIG. 1 illustrate the request for transmission of the graphic primitives formulated by the receiver R to the server B, as well as the transmission of these primitives by the server B to said receiver R.
• FIG. 2 illustrates the rendering processing which is implemented at the level of the receiver R.
• the receiver R comprises means 5 for decoding the initial scene S, as well as means 6 for decoding the primitives P which are transmitted to it by the server B which it interrogates.
• the receiver R further comprises a processing module MT which comprises on the one hand a pre-rendering module PR and, on the other hand a rendering engine MOT.
• the pre-rendering module PR receives the data which correspond to the image of the scene S and implements on it a pre-rendering processing intended to transform these into rendering primitives, for example of the type which are accessible under "open GL.
• the purpose of the PR pre-rendering module is in particular to transform a common graphic representation to adapt it to the specific device on which it is to be displayed.
• the PR module precisely determines the coordinates of the objects to be displayed on the screen. It defines in particular the coordinates of the center of the image, the coordinates of the x and y axes, as well as the dimensions of the rendering area,
• pre-rendering processing one can advantageously refer to the following publications:
• the primitives obtained are transmitted and stored in a stack of primitives which is processed by the graphic rendering engine MOT.
• This MOT rendering engine is to control the display of objects, using for them the positioning and sizing elements which have been determined by the prerend PR module.
• the graphic objects whose display engine MOT controls the display are for example coded in a format similar to that described in the document
• the display command processing performed by the MOT rendering engine makes it possible in particular to manage display conflicts between different objects and is for example of the type described in the document.
• the processing module MT When the processing module MT must prepare the composite graphical object OC, the primitives P which correspond to it are directly sent to the processing stack of the rendering engine, without pre-rendering processing. These primitives are in fact suitable for being displayed directly on the screen, without requiring and does not require pre-rendering processing and in particular adaptation of dimensions.
• the rendering of the LowGraphics object is carried out by the display directly on the screen of the graphic primitives received by the server B.
• the MOT engine implements on the stack of primitives constituted by the stacking of the primitives from the pre-rendering processing and the primitives received by the receiver for the composite graphic object (s), a processing which is by example of the type described in the following publications:
• the first example corresponds to a classic representation of this object
• the second example corresponds to a composite representation, combining a classical representation and a representation with low-level primitives.
• Shape ⁇ geometry IndexedLineSet ⁇ point [2 1 0, 5 2 0, 8 1.5 0, 11 9 0, 14 7 0, 17 10 0] coordlndex [0 1 2 3 4 5] # connect the dots color Color ⁇ color [. 1 .1 .1, .2 .2 .2, .15 .15 .15, .9.9.9, -7.7.7,111] ⁇
• attributes of the “LowGraphics” object are used to describe how the said object can be processed and composed.
• the example presented above thus proposes the use of a "startTime” attribute making it possible to control the triggering of the display, after a determined time, of the primitives corresponding to the data received for the "LowGraphics" object.
• This information allows the receiver in particular to prepare the download (cf. arrows 3 and 4 of FIG. 1 respectively illustrating the request for transmission of the primitives describing the LowGraphics object and the transmission of these primitives) and the possible decoding of the signal describing the object in question.
• the initial image is broken down into a spatio-temporal arrangement of graphic objects and sub-objects.
• Some of these graphic objects can be represented in the form of low-level primitives, for example primitives of the type ⁇ action, polygon, duration ⁇ .
• step Eoc encoded (step Eoc) to be stored in source B in the form of rendering primitives P.
• step Es The rest of the scene, and in particular the various other graphic objects, as well as the general spatio-temporal arrangement of the various graphic objects of the scene, is encoded in a conventional manner (step Es) to be stored in source A.
• step Es The rest of the scene, and in particular the various other graphic objects, as well as the general spatio-temporal arrangement of the various graphic objects of the scene, is encoded in a conventional manner (step Es) to be stored in source A.
• a graphic object is generally represented by a polygonal shape.
• Graphic primitives can describe polygons in the form of lists of points (the vertices of the polygon), possibly associating them with colors and textures.
• the primitives define the objects only from triangular or trapezoidal shapes.
• the primitives then give only the definitions of these triangles or trapezoids and possibly the colors and textures which are associated with them.
• the program below gives an example of encoding in low level primitives for a polygon of the dodecahedron type with 12 faces of 5 points.
• each face can be broken down into 3 triangles, each triangle has 3 coordinate points (X, Y).
• the servers can transmit the data to the client using a “push” type technology.

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Computer Graphics (AREA)
• Geometry (AREA)
• Software Systems (AREA)
• Processing Or Creating Images (AREA)

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• 2003
  • 2003-02-21 FR FR0302144A patent/FR2851716A1/fr active Pending
• 2004
  • 2004-02-18 EP EP04712073A patent/EP1597648A2/de not_active Withdrawn
  • 2004-02-18 US US10/546,347 patent/US20060256117A1/en not_active Abandoned
  • 2004-02-18 WO PCT/FR2004/000364 patent/WO2004077915A2/fr not_active Ceased
  • 2004-02-18 CN CNB2004800048715A patent/CN100531376C/zh not_active Expired - Fee Related
  • 2004-02-18 KR KR1020057015232A patent/KR20050103297A/ko not_active Ceased
  • 2004-02-18 JP JP2006505673A patent/JP2006523337A/ja active Pending

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