System and method for encoding a video sequence using spatial and temporal transforms

Claim 2

An video data processing system, comprising: apparatus for providing a sequence of video frames, each video frame containing an array of image data representing an image; a spatial transform module for performing a spatial decomposition transform on the video frames to generate spatially transformed video frames; each of the spatially transformed video frames including a plurality of subbands of data, including at least one low spatial frequency subband of data; and memory for storing the spatially transformed video frames; a temporal transform module for performing a temporal decomposition transform on blocks of the spatially transformed video frames, each block containing a predefined number of the spatially transformed video frames in a sequence corresponding to the sequence of the corresponding video frames, the temporal transform module applying a temporal decomposition transform to the at least one low spatial frequency subband of data in the spatially transformed video frames so as to generate temporally transformed video data for the at least one low spatial frequency subband of data in the spatially transformed video frames; and a data encoder for encoding, for each block of video frames, the temporally transformed video data and the subbands of data, if any, of the spatially transformed video frames in the block to which the temporal decomposition transform was not applied.

Claim 3

The image processing system of claim 1 , wherein the temporal decomposition transform is an asymmetric transform that extends beyond a current block of spatially transformed video frames to a trailing edge of a previous block of spatially transformed video frames but does not extend beyond the current block of spatially transformed video frames to a next block of spatially transformed video frames.

Claim 4

The image processing system of claim 2 , wherein the temporal decomposition transform is a wavelet or wavelet-like decomposition transform.

Claim 5

The image processing system of claim 2 , wherein the at least one low spatial frequency subband includes, for each video frame, a plurality of coefficients at positions (i,j); the temporal decomposition transform includes a plurality of transform layers, including first, second and last transform layers, each of the plurality of transform layers other than the last transform layer producing intermediate coefficients for input to a next transform layer; the system includes an edge data buffer for storing, for each coefficient in the at least one low spatial frequency subband, at least one intermediate coefficient generated by the temporal decomposition transform when applied to the previous block of video frames; and the temporal transform module is configured to use the at least one intermediate coefficient stored in the edge buffer for each coefficient in the at least one low spatial frequency subband as input to at least one of the transform layers of the temporal decomposition transform when the temporal decomposition transform is applied to the current block of video frames.

Claim 6

The image processing system of claim 2 , wherein the spatial decomposition transform is a discrete cosine transform.

Claim 9

The method of claim 6 , wherein the temporal decomposition transform is an asymmetric transform that extends beyond a current block of spatially transformed video frames to a trailing edge of a previous block of spatially transformed video frames but does not extend beyond the current block of spatially transformed video frames to a next block of spatially transformed video frames.

Claim 10

The method of claim 7 , wherein the temporal decomposition transform is a wavelet or wavelet-like decomposition transform.

Claim 11

The method of claim 7 , wherein the at least one low spatial frequency subband includes, for each video frame, a plurality of coefficients at positions (i,j); the temporal decomposition transform includes a plurality of transform layers, including first, second and last transform layers, each of the plurality of transform layers other than the last transform layer producing intermediate coefficients for input to a next transform layer; the performing a temporal decomposition transform includes storing, for each coefficient in the at least one low spatial frequency subband, at least one intermediate coefficient generated by the temporal decomposition transform when applied to the previous block of video frames; and the performing a temporal decomposition transform includes using the at least one intermediate coefficient stored in the edge buffer for each coefficient in the at least one low spatial frequency subband as input to at least one of the transform layers of the temporal decomposition transform when the temporal decomposition transform is applied to the current block of video frames.

Claim 12

The method of claim 7 , wherein the spatial decomposition transform is a discrete cosine transform.

Claim 13

A computer program product for use in conjunction with a computer system, the computer program product comprising a computer readable storage medium and a computer program mechanism embedded therein, the computer program mechanism comprising: a spatial transform module for performing a spatial decomposition transform on the video frames to generate spatially transformed video frames; each of the spatially transformed video frames including a plurality of subbands of data, including at least one low spatial frequency subband of data; and a temporal transform module for performing a temporal decomposition transform on blocks of the spatially transformed video frames, each block containing a predefined number of the spatially transformed video frames in a sequence corresponding to the sequence of the corresponding video frames, the temporal transform module applying a temporal decomposition transform to the at least one low spatial frequency subband of data in the spatially transformed video frames so as to generate temporally transformed video data for the at least one low spatial frequency subband of data in the spatially transformed video frames; and a data encoding module for encoding, for each block of video frames, the temporally transformed video data and the subbands of data, if any, of the spatially transformed video frames in the block to which the temporal decomposition transform was not applied.

Claim 14

A computer program product for use in conjunction with a computer system, the computer program product comprising a computer readable storage medium and a computer program mechanism embedded therein, the computer program mechanism comprising: a spatial transform module for performing a spatial decomposition transform on the video frames to generate spatially transformed video frames; each of the spatially transformed video frames including a plurality of subbands of data, including at least one low spatial frequency subband of data; and a temporal transform module for performing a temporal decomposition transform on blocks of the spatially transformed video frames, each block containing a predefined number of the spatially transformed video frames in a sequence corresponding to the sequence of the corresponding video frames, the temporal transform module applying a temporal decomposition transform to the at least one low spatial frequency subband of data in the spatially transformed video frames so as to generate temporally transformed video data for the at least one low spatial frequency subband of data in the spatially transformed video frames; and a data encoding module for encoding, for each block of video frames, the temporally transformed video data and the subbands of data, if any, of the spatially transformed video frames in the block to which the temporal decomposition transform was not applied.

Claim 15

The computer program product of claim 1 1 , wherein the temporal decomposition transform is an asymmetric transform that extends beyond a current block of spatially transformed video frames to a trailing edge of a previous block of spatially transformed video frames but does not extend beyond the current block of spatially transformed video frames to a next block of spatially transformed video frames.

Claim 16

The computer program product of claim 12 , wherein the temporal decomposition transform is a wavelet or wavelet-like decomposition transform.

Claim 17

The computer program product of claim 12 , wherein the at least one low spatial frequency subband includes, for each video frame, a plurality of coefficients at positions (i,j); the temporal decomposition transform includes a plurality of transform layers, including first, second and last transform layers, each of the plurality of transform layers other than the last transform layer producing intermediate coefficients for input to a next transform layer; the system includes an edge data buffer for storing, for each coefficient in the at least one low spatial frequency subband, at least one intermediate coefficient generated by the temporal decomposition transform when applied to the previous block of video frames; and the temporal transform module is configured to use the at least one intermediate coefficient stored in the edge buffer for each coefficient in the at least one low spatial frequency subband as input to at least one of the transform layers of the temporal decomposition transform when the temporal decomposition transform is applied to the current block of video frames.

Claim 18

The computer program product of claim 12 , wherein the spatial decomposition transform is a discrete cosine transform.