Method and Apparatus to Perform Optimal Visually-Weighed Quantization of Time-Varying Visual Sequences in Transform Space

Abstract

Pure transform-based technologies, such as the DCT or wavelets, can leverage a mathematical model based on few or one parameters to generate the expected distribution of the transform components' energy, and generate ideal entropy removal configuration data continuously responsive to changes in video behavior. Construction of successive-refinement streams is supported by this technology, permitting response to changing channel conditions. Lossless compression is also supported by this process. The embodiment described herein uses a video correlation model to develop optimal entropy removal tables and optimal transmission sequence based on a combination of descriptive characteristics of the video source, enabling independent derivation of said optimal entropy removal tables and optimal transmission sequence in both encoder and decoder sides of the compression and playback process.

1 . An apparatus comprised of a compressor and decompressor and a method for generating an optimally compressed representation of multidimensional visual data after transformation by a multidimensional orthogonal transform of a specified transformation block size, after quantization by coefficients of said transformation block size, and after rearrangement of said quantized coefficients into a transmission sequence, and after collection of said quantized transformation coefficients into symbols, by the application of said quantized decorrelating transform to a plurality of measured variances of uncompressed multidimensional visual data and measured correlation coefficients of uncompressed multidimensional visual data to calculate the probability distribution of each quantized transform coefficient required to perform entropy removal, 
     
     
         2 . The method of  claim 1  where said orthogonal transform is the discrete cosine transform, 
     
     
         3 . The method of  claim 1  where said multidimensional visual data comprises a two-dimensional still image, 
     
     
         4 . The method of  claim 3  where said transformation block size comprises the entire image, 
     
     
         5 . The method of  claim 3  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per block and said plurality of correlation coefficients is one averaged value per frame, 
     
     
         6 . The method of  claim 3  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per block and said plurality of correlation coefficients is one averaged value per block, 
     
     
         7 . The method of  claim 3  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per dimension per frame and said plurality of correlation coefficients is one averaged value per dimension per frame, 
     
     
         8 . The method of  claim 3  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per block and said plurality of correlation coefficients is one averaged value per dimension per block, 
     
     
         9 . The method of  claim 1  where said multidimensional visual data comprises a three-dimensional moving video sequence, 
     
     
         10 . The method of  claim 9  where said transformation block size comprises a number of frames by the entire size of a single frame, 
     
     
         11 . The method of  claim 9  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per group of frames and said plurality of correlation coefficients is one averaged value per group of frames, 
     
     
         12 . The method of  claim 9  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per block and said plurality of correlation coefficients is one averaged value per block, 
     
     
         13 . The method of  claim 9  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per dimension per group of frames and said plurality of correlation coefficients is one averaged value per dimension per group of frames, 
     
     
         14 . The method of  claim 9  where said plurality of measured variances of uncompressed multidimensional visual data is one averaged value per dimension per block and said plurality of correlation coefficients is one averaged value per dimension per block, 
     
     
         15 . The method of  claim 1  where said quantizers are all ones, 
     
     
         16 . The method of  claim 1  where said quantizers are all equal, 
     
     
         17 . The method of  claim 1  where said quantizers are visually weighed, 
     
     
         18 . The method of  claim 1  where coefficients are organized within each block into order of decreasing calculated component variance, 
     
     
         19 . The method of  claim 18  where the probability of symbols is calculated from a definition of a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the actual non-zero value, a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the number of bits required to represent the non-zero value, an end-of-block symbol whose conditional expectation is calculated from the cumulative probability of a sequence of symbols comprised solely of zeroes, and an escape symbol whose conditional expectation is calculated from the accumulation of the probability of all symbols not otherwise defined. 
     
     
         20 . The method of  claim 1  where coefficients are organized across blocks into order of decreasing calculated component variance, 
     
     
         21 . The method of  claim 20  where the probability of symbols is calculated from a definition of a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the actual non-zero value, a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the number of bits required to represent the non-zero value, an end-of-block symbol whose conditional expectation is calculated from the cumulative probability of a sequence of symbols comprised solely of zeroes, and an escape symbol whose conditional expectation is calculated from the accumulation of the probability of all symbols not otherwise defined. 
     
     
         22 . The method of  claim 1  where coefficients are organized across blocks into bands of decreasing calculated component variance within of order successive refinement, 
     
     
         23 . The method of  claim 22  where the probability of symbols is calculated from a definition of a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the actual non-zero value, a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the number of bits required to represent the non-zero value, an end-of-block symbol whose conditional expectation is calculated from the cumulative probability of a sequence of symbols comprised solely of zeroes, and an escape symbol whose conditional expectation is calculated from the accumulation of the probability of all symbols not otherwise defined. 
     
     
         24 . The method of  claim 1  where coefficients are organized across blocks into bands of equal weight in order of decreasing calculated component variance, 
     
     
         25 . The method of  claim 24  where the probability of symbols is calculated from a definition of a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the actual non-zero value, a plurality of symbols as collected from sequences of component values whose conditional expectation is zero followed by the number of bits required to represent the non-zero value, an end-of-block symbol whose conditional expectation is calculated from the cumulative probability of a sequence of symbols comprised solely of zeroes, and an escape symbol whose conditional expectation is calculated from the accumulation of the probability of all symbols not otherwise defined. 
     
     
         26 . The method of  claim 1  where Huffman coding based used to perform entropy removal on the constructed stream of symbols, 
     
     
         27 . The method of  claim 26  where said measured variances of uncompressed multidimensional visual data and said measured correlations of uncompressed multidimensional visual data are communicated between compressor and decompressor, 
     
     
         28 . The method of  claim 1  where arithmetic coding based is used to perform entropy removal on the constructed stream of symbols, 
     
     
         29 . The method of  claim 28  where said measured variances of uncompressed multidimensional visual data and said measured correlations of uncompressed multidimensional visual data are communicated between compressor and decompressor, 
     
     
         30 . The method of  claim 1  where said decorrelating transform is any orthonormal wavelet.