Abstract: A technique implicitly encodes shape information by using a chroma-key color. A frame including an object is received and a box bounding the object is created. The pixels in the bounding box outside the object are identified and replaced with a key color. The object is coded. A first bitstream is output that includes the coded data for the pixels in the bounding box, and a second bitstream is output that includes a node containing the key color and chroma-key thresholds for the object. In one embodiment, the node is a MaterialKey node. In a further embodiment, the node comprises a transparency field, an isKeyed field, an isRGB field, a keycolor field, a lowThreshold field, and a highThreshold field.

Abstract: A video coding system that codes video objects as scalable video object layers. Data of each video object may be segregated into one or more layers. A base layer contains sufficient information to decode a basic representation of the video object. Enhancement layers contain supplementary data regarding the video object that, if decoded, enhance the basic representation obtained from the base layer. The present invention thus provides a coding scheme suitable for use with decoders of varying processing power. A simple decoder may decode only the base layer of video objects to obtain the basic representation. However, more powerful decoders may decode the base layer data of video objects and additional enhancement layer data to obtain improved decoded output. The coding scheme supports enhancement of both the spatial resolution and the temporal resolution of video objects.

Abstract: The values of the primary color space components of an image signal, such as the components of RGB video signal, are maintained within their allowed range by modifying the signal in a different color space, such as YUV space. Specifically, the U and V chrominance components are attenuated by an attenuation factor g while the luminance component Y is not modified. The value of g is the largest possible value less than 1 that will cause all primary color space components that would otherwise be outside the allowed range to be within that range. A high quality of the displayed image is maintained.

Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: Systems and methods for reducing bit rates by replacing original texture in a video sequence with synthesized texture. Reducing the bit rate of the video sequence begins by identifying and removing selected texture from frames in a video sequence. The removed texture is analyzed to generate texture parameters. New texture is synthesized using the texture parameters in combination with a set of constraints. Then, the newly synthesized texture is mapped back into the frames of the video sequence from which the original texture was removed. The resulting frames are then encoded. The bit rate of the video sequence with the synthesized texture is less than the bit rate of the video sequence with the original texture. Also, the ability of a decoder to decode the new video sequence is not compromised because no assumptions are made about the texture synthesis capabilities of the decoder.

Abstract: A coding protocol provides for coding video data that has been organized as video objects. The protocol provides a keyregion to permit coding of a region of data within the video object having common attributes. According to the protocol a keyregion is identified by a keyregion header, which includes a resync marker that uniquely identifies the keyregion header, a keyregion position signal indicating an origin and a size of the keyregion; and data of the common attribute. Data following the keyregion is coded according to the common attribute.

Abstract: A video coding system that codes video objects as scalable video object layers. Data of each video object may be segregated into one or more layers. A base layer contains sufficient information to decode a basic representation of the video object. Enhancement layers contain supplementary data regarding the video object that, if decoded, enhance the basic representation obtained from the base layer. The present invention thus provides a coding scheme suitable for use with decoders of varying processing power. A simple decoder may decode only the base layer of video objects to obtain the basic representation. However, more powerful decoders may decode the base layer data of video objects and additional enhancement layer data to obtain improved decoded output. The coding scheme supports enhancement of both the spatial resolution and the temporal resolution of video objects.

Abstract: A coding protocol provides for coding video data that has been organized as video objects. The protocol provides a keyregion to permit coding of a region of data within the video object having common attributes. According to the protocol a keyregion is identified by a keyregion header, which includes a resync marker that uniquely identifies the keyregion header, a keyregion position signal indicating an origin and a size of the keyregion; and data of the common attribute. Data following the keyregion is coded according to the common attribute.

Abstract: A method is provided for decoding a bit stream representing an image that has been encoded The method includes the steps of: performing an entropy decoding of the bit stream to form a plurality of transform coefficents and a plurality of motion vectors; performing an inverse transformation on the plurality of transform coefficients to form a plurality of error blocks; determining a plurality of predicted blocks based on bidirectional motion estimation that employs the motion vectors, wherein the bidirectional motion estimation includes a direct prediction mode and a second prediction mode; and, adding the plurality of error blocks to the plurality of predicted blocks to form the image. The second prediction mode may include forward, backward, and interpolated prediction modes.

Abstract: A system and method for reproducing a multimedia data signal on a terminal. A terminal capability node is instantiated and the terminal capability is evaluated. The value of a capability is set, and the value is then altered based upon the capability of the evaluated terminal.

Abstract: A method is provided for decoding a bit stream representing an image that has been encoded. The method includes the steps of: performing an entropy decoding of the bit stream to form a plurality of transform coefficents and a plurality of motion vectors; performing an inverse transformation on the plurality of transform coefficients to form a plurality of error blocks; determining a plurality of predicted blocks based on bidirectional motion estimation that employs the motion vectors, wherein the bidirectional motion estimation includes a direct prediction mode and a second prediction mode; and, adding the plurality of error blocks to the plurality of predicted blocks to form the image. The second prediction mode may include forward, backward, and interpolated prediction modes.

Abstract: A quantizer and dequantizer for use in a video coding system that applies non linear, piece-wise linear scaling functions to video information signals based on a value of a variable quantization parameter. The quantizer and dequantizer apply different non linear, piece-wise linear scaling functions to a DC luminance signal, a DC chrominance signal and an AC chrominance signal. A code for reporting updates of the value of the quantization parameter is interpreted to require larger changes when the quantization parameter initially is large and smaller changes when the quantization parameter initially is small.

Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: A quantizer and dequantizer for use in a video coding system that applies non linear, piece-wise linear scaling functions to video information signals based on a value of a variable quantization parameter. The quantizer and dequantizer apply different non linear, piece-wise linear scaling functions to a DC luminance signal, a DC chrominance signal and an AC chrominance signal. A code for reporting updates of the value of the quantization parameter is interpreted to require larger changes when the quantization parameter initially is large and smaller changes when the quantization parameter initially is small.

Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: A system and method for reproducing a multimedia data signal on a terminal. A terminal capability node is instantiated and the terminal capability is evaluated. The value of a capability is set, and the value is then altered based upon the capability of the evaluated terminal.

Abstract: A video coding system that codes video objects as scalable video object layers. Data of each video object may be segregated into one or more layers. A base layer contains sufficient information to decode a basic representation of the video object. Enhancement layers contain supplementary data regarding the video object that, if decoded, enhance the basic representation obtained from the base layer. The present invention thus provides a coding scheme suitable for use with decoders of varying processing power. A simple decoder may decode only the base layer of video objects to obtain the basic representation. However, more powerful decoders may decode the base layer data of video objects and additional enhancement layer data to obtain improved decoded output. The coding scheme supports enhancement of both the spatial resolution and the temporal resolution of video objects.

Abstract: A method for increasing compression efficiency of a stereoscopic image encoder employed for compressively encoding first and second signals representing respective first and second views of a stereoscopic image, comprises: providing a first histogram of the first view and a second histogram of the second view, the first and second histograms representing a frequency of occurrence of a characteristic component of the first and second views, respectively; comparing the first histogram of the first view with the second histogram of the second view and estimating the mismatch in gain, a, and mismatch in offset, b, between the first and second views; correcting the stereoscopic image by multiplying the gain a and the second signal to obtain a gain corrected second signal for the stereoscopic image and adding the offset b to the gain corrected second signal to obtain a gain and offset corrected second signal, the gain and offset corrected second signal being obtained prior to encoding to increase encoding efficienc

Abstract: In a system and method for transmitting and displaying multiple different views of a scene, three or more simultaneous scene signals, representing multiple different views of a scene, are provided by an appropriate camera arrangement to a spatial multiplexer. The size and resolution of the scene signals are reduced as necessary to combine the multiple scene signals into two super-view signals. The super-view signals are encoded using compression based on redundancies between the two super-views and then transmitted. A decoder receives the transmitted data signal and extracts the two super-view signals according to the inverse of the encoding operation. A spatial demultiplexer recovers the individual scene signals from the decoded super-view signals in accordance with a defined multiplexed order and arrangement. The scene signals are then interpolated as needed to restore the original resolution and size and subsequently displayed.