Title of Invention  A SYSTEM AND METHOD FOR DECODING DIGITAL IMAGE AND AUDIO DATA IN A LOSSLESS MANNER 

Abstract  ABSTRACT A SYSTEM AND METHOD FOR DECODING DIGITAL IMAGE AND AUDIO DATA IN A LOSSLESS MANNER A method of losslessly decoding signals representing an image is claimed. A lossy compressed data file and a residual compressed data file are received. The lossy compressed data file is separated into DC coefficients and AC coefficients, and decoded, separately, to the determine DC values and the AC values (130). The DC values and the AC values are inverse quantized to produce lossy, decompressed data (146). The lossy decompressed frequency data is combined with the residual decompressed data to produce a lossless data file, wherein the lossless data file is substantially the same as the original image. Figure 14 
Full Text  BACKGROUND OF THE INVENTION I. Field of the Invention [0001] The present invention relates to image processing and compression and decompression. More specifically, the invention relates to lossless decoding of digital image and audio information in the frequency domain. II. Description of the Related Art [0002] Digital picture processing has a prominent position in the general discipline of digital signal processing. The importance of human visual perception has encouraged tremendous interest and advances in the art and science of digital picture processing. In the field of transmission and reception of video signals, such as those used for projecting films or movies, various improvements are being made to image compression techniques. Many of the current and proposed video systems make use of digital encoding techniques. Aspects of this field include image coding, image restoration, and image feature selection. Image coding represents the attempts to transmit pictures of digital communication channels in an efficient manner, making use of as few bits as possible to minimize the band width required, while at the same time, maintaining distortions within certain limits. Image restoration represents efforts to recover the true image of the object. The coded image being transmitted over a communication channel may have been distorted by various factors. Source of degradation may have arisen originally in creating the image from the object. Feature selection refers to the selection of certain attributes of the picture. Such attributes may be required in the recognition, classification, and decision in a wider context. [0003] Digital encoding of video, such as that in digital cinema, is an area that benefits from improved image compression techniques. Digital image compression may be generally classified into two categories: lossless and lossy methods. A lossless image is recovered without any loss of information. A lossy method involves an irrecoverable loss of some information, depending upon the compression ratio, the quality of the compression algorithm, and the implementation of the algorithm. Generally, lossy compression approaches are considered to obtain the compression ratios desired for a costeffective digital cinema approach. To achieve digital cinema quality levels, the compression approach should provide a visually lossless level of performance. As such, although there is a mathematical loss of information as a result of the compression process, the image distortion caused by this loss should be imperceptible to a viewer under normal viewing conditions. [0004] Existing digital image compression technologies have been developed for other applications, namely for television systems. Such technologies have made design compromises appropriate for the intended application, but do not meet the quality requirements needed for cinema presentation. [0005] Digital cinema compression technology should provide the visual quality that a moviegoer has previously experienced. Ideally, the visual quality of digital cinema should attempt to exceed that of a highquality release print film. At the same time, the compression technique should have high coding efficiency to be practical. As defined herein, coding efficiency refers to the bit rate needed for the compressed image quality to meet a certain qualitative level. Moreover, the system and coding technique should have builtin flexibility to accommodate different formats and should be cost effective; that is, a smallsized and efficient decoder or encoder process. [0006] Many compression techniques available offer significant levels of compression, but result in a degradation of the quality of the video signal. Typically, techniques for transferring compressed information require the compressed information to be transferred at a constant bit rate. [0007] One compression technique capable of offering significant levels of compression while preserving the desired level of quality for video signals utilizes adaptively sized blocks and subblocks of encoded Discrete Cosine Transform (DCT) coefficient data. This technique will hereinafter be referred to as the Adaptive Block Size Discrete Cosine Transform (ABSDCT) method. This technique is disclosed in U. S. Patent No. 5,021,891, entitled "Adaptive Block Size Image Compression Method And System," assigned to the assignee of the present invention and incorporated herein by reference. DCT techniques are also disclosed in U. S. Patent No. 5,107,345, entitled "Adaptive Block Size Image Compression Method And System," assigned to the assignee of the present invention and incorporated herein by reference. Further, the use of the ABSDCT technique in combination with a Differential Quadtree Transform technique is discussed 3 in U. S. Patent No. 5,452,104, entitled "Adaptive Block Size Image Compression Method And System," also assigned to the assignee of the present invention and incorporated herein by reference. The systems disclosed in these patents utilize what is referred to as "intraframe" encoding, where each frame of image data is encoded without regard to the content of any other frame. Using the ABSDCT technique, the achievable data rate may be reduced from around 1.5 billion bits per second to approximately 50 million bits per second without discernible degradation of the image quality. [0008] The ABSDCT technique may be used to compress either a black and white or a color image or signal representing the image. The color input signal may be in a YIQ format, with Y being the luminance, or brightness, sample, and I and Q being the chrominance, or color, samples for each 4:4:4 or alternate format.. Other known formats such as the YUV, YQ,Cr or RGB formats may also be used. Because of the low spatial sensitivity of the eye to color, most research has shown that a subsample of the color components by a factor of four in the horizontal and vertical directions is reasonable. Accordingly, a video signal may be represented by four luminance components and two chrominance components. [0009] Using ABSDCT, a video signal will generally be segmented into blocks of pixels for processing. For each block, the luminance and chrominance components are passed to a block interleaver. For example, a 16x16 (pixel) block may be presented to the block interleaver, which orders or organizes the image samples within each 16x16 block to produce blocks and composite subblocks of data for discrete cosine transform (DCT) analysis. The DCT operator is one method of converting a time and spatial sampled signal to a frequency representation of the same signal. By converting to a frequency representation, the DCT techniques have been shown to allow for very high levels of compression, as quantizers can be designed to take advantage of the frequency distribution characteristics of an image. In a preferred embodiment, one 16x16 DCT is applied to a first ordering, four 8x8 DCTs are applied to a second ordering, 16 4x4 DCTs are applied to a third ordering, and 64 2x2 DCTs are applied to a fourth ordering. [0010] The DCT operation reduces the spatial redundancy inherent in the video source. After the DCT is performed, most of the video signal energy tends to be concentrated in a few DCT coefficients. An additional transform, the Differential QuadTree Transform (DQT), may be used to reduce the redundancy among the DCT coefficients. [0011] For the 16x16 block and each subblock, the DCT coefficient values and the DQT value (if the DQT is used) are analyzed to determine the number of bits required to encode the block or subblock. Then, the block or the combination of subblocks that requires the least number of bits to encode is chosen to represent the image segment. For example, two 8x8 subblocks, six 4x4 subblocks, and eight 2x2 subblocks may be chosen to represent the image segment. [0012] The chosen block or combination of subblocks is then properly arranged in order into a 16x16 block. The DCT/DQT coefficient values may then undergo frequency weighting, quantization, and coding (such as variable length, coding) in preparation for transmission. Although the ABSDCT technique described above performs remarkably well, it is computationally intensive. [0013] Further, although use of the ABSDCT is visually lossless, it is sometimes desirable to recover data in the exact manner in which it was encoded. For example, mastering and archival purposes require to compress data in such a way as to be able to recover it exactly in its native domain. [0014] Traditionally, a lossless compression system for images consists of a predictor, which estimates the value of the current pixel to be encoded. A residual pixel is obtained as the difference between the actual and the predicted pixel. The residual pixel is then entropy encoded and stored or transmitted. Since the prediction removes pixel correlation, the residual pixels have a reduced dynamic range with a characteristic twosided exponential (Laplacian) distribution. Hence the compression. The amount of compression of the residuals depends on both the prediction and subsequent entropy encoding methods. Most commonly used prediction methods are differential pulse code modulation (DPCM) and its variants such as the adaptive DPCM (ADPCM). [0015] A problem with pelbased prediction is that the residuals still have a high energy. It is due to the fact that only a small number of neighboring pixels are used in the prediction process. Therefore there is room to improve the coding efficiency of pelbased prediction schemes SUMMARY OF THE INVENTION [0016] Embodiments of the invention describe a system to encode digital image and video data in a lossless manner to achieve compression. The system is hybrid  meaning that it has a part that compresses the said data in a lossy manner and a part that compresses the residual data in a lossless fashion. For the lossy part, the system uses the adaptive block size discrete cosine transform (ABSDCT) algorithm. The ABSDCT system compresses the said data yielding a high visual quality and compression ratio. A residual image is obtained as the difference between the original and the decompressed one from the ABSDCT system. This residual is encoded losslessly using GolombRice coding algorithm. Due to visually based adaptive block size and quantization of the DCT coefficients, the residuals have a very low energy, thus yielding good overall lossless compression ratios. [0017] The ABSDCT system achieves a high compression ratio at cinema quality. Since it is blockbased, it removes pixel correlation much better than any pelbased scheme. Therefore it is used as a predictor in the lossless system to be described here. In conjunction with this predictor a lossless encoding system is added to form a hybrid lossless compression system. It should be noted that the system is capable of compressing still images as well as motion images. If it is a still image, only the ABSDCT compressed data and entropy encoded residual data are used as the compressed output. For motion sequences, a decision is made whether to use intraframe or interframe compression. For example, if /(?) represents an image frame at time instant t, F(t) and F(t + At) denote the DCTs of the image frames at time instants t and t + Hi, respectively. Note that Ar corresponds to the time interval between two consecutive frames. The invention is embodied in an apparatus and method for compressing data that allows one to be able to recover the data in the exact manner in which the data was encoded. Embodiments comprise a system that performs intraframe coding, interframe coding, or a hybrid of the two. The system is a quality based system that utilizes adaptively sized blocks and subblocks of Discrete Cosine Transform coefficient data. A method of losslessly decoding signals representing an image is claimed. A lossy compressed data file and a residual compressed data file are received. The lossy compressed data file is separated into DC coefficients and AC coefficients, and decoded, separately, to the determine DC values and the AC values. The the DC values and the AC values are inverse quantized to produce lossy, decompressed data. The residual compressed data file is decoded to produce a residual decompressed data. The lossy decompressed frequency data is combined with the residual decompressed data to produce a lossless data file, wherein the lossless data file is substantially the same as the original image. [0018] The use of a hybrid compression system such as the ABSDCT, acts like a good predictor of pixel or DCT values. Therefore it results in a higher lossless compression ratio than the systems using pelbased prediction. For the lossless portion, unlike Huffman codes, GolombRice coding does not require any a priori code generation. Therefore, it does not require an extensive code book to be stored as in Huffman coding. This results in an efficient use of the chip real estate. Hence, the chip size is reduced in hardware implementation. Further, the GolombRice encoding is much simpler to implement than Huffman coding. Also, GolombRice coding achieves a higher coding efficiency than the Huffman coding as the DCT' coefficients or residuals have an exponential distribution naturally. Further, as the lossy portion of the compression system uses visually significant information in the block subdivision, context modeling is inherent in the residual encoding. This is important in that no extra storage registers are needed in gathering contextual data for the residual encoding. Since no motion estimation is used, the system is very simple to implement also. [0019] Accordingly, it is an aspect of an embodiment to provide an apparatus and method to efficiently provide lossless compression. [0020] It is another aspect of an embodiment that compresses digital image and audio information losslessly in a manner conducive to mastering and archival purposes. BRIEF DESCRIPTION OF THE DRAWINGS [0021] The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein: [0022] FIG. 1 is a block diagram of an encoder portion of an image compression and processing system; [0023] FIG. 2 is a block diagram of a decoder portion of an image compression and processing system; [0024] FIG. 3 is a flow diagram illustrating the processing steps involved in variance based block size assignment; [0025] FIG. 4a illustrates an exponential distribution of the Y component of zero run lengths in a DCT coefficient matrix; [0026] FIG. 4b illustrates an exponential distribution of the Cb component of zero run lengths in a DCT coefficient matrix; [0027] FIG. 4c illustrates an exponential distribution of the Cr component of zero run lengths in a DCT coefficient matrix; [0028] FIG. 5a illustrates an exponential distribution of the Y component of amplitude size in a DCT coefficient matrix; [0029] FIG. 5b illustrates an exponential distribution of the Cb component of amplitude size in a DCT coefficient matrix; [0030] FIG. 5c illustrates an exponential distribution of the Cr component of amplitude size in a DCT coefficient matrix; [0031] FIG. 6 illustrates a GolombRice encoding process; [0032] FIG. 7 illustrates an apparatus for GolombRice encoding; [0033] FIG. 8 illustrates a process of encoding DC component values; [0034] FIG. 9 illustrates an apparatus for lossless compression; [0035] FIG. 10 illustrates a method of hybrid lossless compression; and [0036] FIG. 11 illustrates an apparatus for lossless decompression. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0037] In order to facilitate digital transmission of digital signals and enjoy the corresponding benefits, it is generally necessary to employ some form of signal compression. To achieve high compression in a resulting image, it is also important that high quality of the image be maintained. Furthermore, computational efficiency is desired for compact hardware implementation, which is important in many applications. [0038] Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and are carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for purpose of description and should not be regarded as limiting. [0039] Image compression employed in an aspect of an embodiment is based on discrete cosine transform (DCT) techniques, such as that disclosed in copending U.S. Patent Application "Contrast Sensitive Variance Based Adaptive Block Size DCT Image Compression", Serial No. 09/436,085 filed on November 8, 1999, assigned to the assignee of the present application and incorporated herein by reference. Image Compression and Decompression systems utilizing the DCT are described in copending U.S. Patent Application "Quality Based Image Compression", Serial No. 09/494,192, filed on January, 28, 2000, assigned to the assignee of the present application and incorporated herein by reference. Generally, an image to be processed in the digital domain is composed of pixel data divided into an array of nonoverlapping blocks, NxN in size. A twodimensional DCT may be performed on each block. The twodimensional DCT is defined by the following relationship: X(k,l) = JN*M m*0n=0 jt(/?j,ra)cos '(2m + l)afc' 2JV cos (271 + 1)^ IN ,0 fl, ifk=0 where **),#*)j^^ , and x(m,n) is the pixel at location (m,n) within an NxM block, and X(k,l) is the corresponding DCT coefficient. [0040] Since pixel values are nonnegative, the DCT component X(0,0) is always positive and usually has the most energy. In fact, for typical images, most of the transform energy is concentrated around the component X(0,0). This energy compaction property is what makes the DCT technique such an attractive compression method. [0041] The image compression technique utilizes contrast adaptive coding to achieve further bit rate reduction. It has been observed that most natural images are made up of relatively slow varying flat areas, and busy areas such as object boundaries and highcontrast texture. Contrast adaptive coding schemes take advantage of this factor by assigning more bits to the busy areas and less bits to the less busy areas. [0042] Contrast adaptive methods utilize intraframe coding (spatial processing) instead of interframe coding (spatiotemporal processing). Interframe coding inherently requires multiple frame buffers in addition to more complex processing circuits. In many applications, reduced complexity is needed for actual implementation. Intraframe coding is also useful in a situation that can make a spatiotemporal coding scheme break down and perform poorly. For example, 24 frame per second movies can fall into this category since the integration time, due to the mechanical shutter, is relatively short. The short integration time allows a higher degree of temporal aliasing. The assumption of frame to frame correlation breaks down for rapid motion as it becomes jerky. Intraframe coding is also easier to standardize when both 50 Hz and 60 Hz power line frequencies are involved. Television currently transmits signals at either 50 Hz or 60 Hz. The use of an intraframe scheme, being a digital approach, can adapt to both 50 Hz and 60 Hz operation, or even to 24 frame per second movies by trading off frame rate versus spatial resolution. [0043] For image processing purposes, the DCT operation is performed on pixel data that is divided into an array of nonoverlapping blocks. Note that although block sizes are discussed herein as being NxN in size, it is envisioned that various block sizes may be used. For example, a NxM block size may be utilized where both N and M are integers with M being either greater than or less than N. Another important aspect is that the block is divisible into at least one level of subblocks, such as N/ixN/z, N/ixN/j, N/z'xM//, and etc. where i and j are integers. Furthermore, the exemplary block size as discussed herein is a 16x16 pixel block with corresponding block and subblocks of DCT coefficients. It is further envisioned that various other integers such as both even or odd integer values may be used, e.g. 9x9. [0044] FIGs. 1 and 2 illustrate an image processing system 100 incorporating the concept of configurable serializer. The image processing system 100 comprises an encoder 104 that compresses a received video signal. The compressed signal is transmitted using a transmission channel or a physical medium 108, and received by a decoder 112. The decoder 112 decodes the received encoded data into image samples, which may then be exhibited. [0045] In general, an image is divided into blocks of pixels for processing. A color signal may be converted from RGB space to YC1C2 space using a RGB to YC1C2 converter 116, where Y is the luminance, or brightness, component, and Q and C2 are the chrominance, or color, components. Because of the low spatial sensitivity of the eye to color, many systems subsample the C\ and C2 components by a factor of four in the horizontal and vertical directions. However, the subsampling is not necessary. A full resolution image, known as 4:4:4 format, may be either very useful or necessary in some applications such as those referred to as covering "digital cinema." Two possible YC\C2 representations are, the YTQ representation and the YUV representation, both of which are well known in the art. It is also possible to employ a variation of the YUV representation known as YCbCr. This may be further broken into odd and even components. Accordingly, in an embodiment the representation Yeven, Yodd, Cbeven, Cbodd, Creven, Crodd is used. [0046] In a preferred embodiment, each of the even and odd Y, Cb, and Cr components is processed without subsampling. Thus, an input of each of the six components of a 16x16 block of pixels is provided to the encoder 104. For illustration purposes, the encoder 104 for the Yeven component is illustrated. Similar encoders are used for the Yodd component, and even and odd Cb and Cr components. The encoder 104 comprises a block size assignment element 120, which performs block size assignment in preparation for video compression. The block size assignment element 120 determines the block decomposition of the 16x16 block based on the perceptual characteristics of the image in the block. Block size assignment subdivides each 16x16 block into smaller blocks, such as 8x8,4x4, and 2x2, in a quadtree fashion depending on the activity within a 16x16 block. The block size assignment element 120 generates a quadtree data, called the PQR data, whose length can be between 1 and 21 bits. Thus, if block size assignment determines that a 16x16 block is to be divided, the R bit of the PQR data is set and is followed by four additional bits of Q data corresponding to the four divided 8x8 blocks. If block size assignment determines that any of the 8x8 blocks is to be subdivided, then four additional bits of P data for each 8x8 block subdivided are added. [0047] Referring now to FIG. 3, a flow diagram showing details of the operation of the block size assignment element 120 is provided. The variance of a block is used as a metric in the decision to subdivide a block. Beginning at step 202, a 16x16 block of pixels is read. At step 204, the variance, vl6, of the 16x16 block is computed. The variance is computed as follows: N i=o j=o var 1 N1N1 I 1 N1N1 ^■N i*>0 j=0 J where N=16, and XQ is the pixel in the zth row, /h column within the NxN block. A't step 206, first the variance threshold T16 is modified to provide a new threshold T'16 if the mean value of the block is between two predetermined values, then the block variance is compared against the new threshold, T16. [0048] If the variance vl6 is not greater than the threshold 776, then at step 208, the starting address of the 16x16 block is written into temporary storage, and the R bit of the PQR data is set to 0 to indicate that the 16x16 block is not subdivided. The algorithm then reads the next 16x16 block of pixels. If the variance vl6 is greater than the threshold 776, then at step 210, the R bit of the PQR data is set to 1 to indicate that the 16x16 block is to be subdivided into four 8x8 blocks. [0049] The four 8x8 blocks, 1=1:4, are considered sequentially for further subdivision, as shown in step 212. For each 8x8 block, the variance, v8h is computed, at step 214. At step 216, first the variance threshold T8 is modified to provide a new threshold T'8 if the mean value of the block is between two predetermined values, then the block variance is compared to this new threshold. [0050] If the variance v8i is not greater than the threshold T8, then at step 218, the starting address of the 8x8 block is written into temporary storage, and the corresponding Q bit, Qi, is set to 0. The next 8x8 block is then processed. If the variance v8t is greater than the threshold T8, then at step 220, the corresponding Q bit, [0051] The four 4x4 blocks, /,=1:4, are considered sequentially for further subdivision, as shown in step 222. For each 4x4 block, the variance, v4ij, is computed, at step 224. At step 226, first the variance threshold T4 is modified to provide a new threshold T'4 if the mean value of the block is between two predetermined values, then the block variance is compared to this new threshold. [0052] If the variance v4y is not greater than the threshold T4, then at step 228, the address of the 4x4 block is written, and the corresponding P bit, Py, is set to 0. The next 4x4 block is then processed. If the variance vfy is greater than the threshold T4, then at step 230, the corresponding P bit, Py, is set to 1 to indicate that the 4x4 block is to be subdivided into four 2x2 blocks. In addition, the address of the 4 2x2 blocks are written into temporary storage. [0053] The thresholds 776", T8, and T4 may be predetermined constants. This is known as the hard decision. Alternatively, an adaptive or soft decision may be implemented. For example, the soft decision varies the thresholds for the variances depending on the mean pixel value of the 2Nx2N blocks, where N can be 8, 4, or 2. Thus, functions of the mean pixel values, may be used as the thresholds. [0054] For purposes of illustration, consider the following example. Let the predetermined variance thresholds for the Y component be 50, 1100, and 880 for the 16x16, 8x8, and 4x4 blocks, respectively. In other words, T16 = 50, T8 = 1100, and T4 = 880. Let the range of mean values be 80 and 100. Suppose the computed variance for the 16x16 block is 60. Since 60 is greater than T16, and the mean value 90 is between 80 and 100, the 16x16 block is subdivided into four 8x8 subblocks. Suppose the computed variances for the 8x8 blocks are 1180, 935, 980, and 1210. Since two of the 8x8 blocks have variances that exceed T8, these two blocks are further subdivided to produce a total of eight 4x4 subblocks. Finally, suppose the variances of the eight 4x4 blocks are 620, 630, 670, 610, 590, 525, 930, and 690, with corresponding means values 90, 120, 110, 115. Since the mean value of the first 4x4 block falls in the range (80, 100), its threshold will be lowered to 2"4=200 which is less than 880. So, this 4x4 block will be subdivided as well as the seventh 4x4 block. [0055] Note that a similar procedure is used to assign block sizes for the luminance component Yodd and the color components, Cbeven, CWa, Cr.even and Cr.0dd. The color components may be decimated horizontally, vertically, or both. [0056] Additionally, note that although block size assignment has been described as a top down approach, in which the largest block (16x16 in the present example) is evaluated first, a bottom up approach may instead be used. The bottom up approach will evaluate the smallest blocks (2x2 in the present example) first. [0057] Referring back to FIG. 1, the PQR data, along with the addresses of the selected blocks, are provided to a DCT element 124. The DCT element 124 uses the PQR data to perform discrete cosine transforms of the appropriate sizes on the selected blocks. Only the selected blocks need to undergo DCT processing. [0058] The image processing system 100 also comprises DQT element 128 for reducing the redundancy among the DC coefficients of the DCTs. A DC coefficient is encountered at the top left corner of each DCT block. The DC coefficients are, in general, large compared to the AC coefficients. The discrepancy in sizes makes it difficult to design an efficient variable length coder. Accordingly, it is advantageous to reduce the redundancy among the DC coefficients. [0059] The DQT element 128 performs 2D DCTs on the DC coefficients, taken 2x2 at a time. Starting with 2x2 blocks within 4x4 blocks, a 2D DCT is performed on the four DC coefficients. This 2x2 DCT is called the differential quadtree transform, or DQT, of the four DC coefficients. Next, the DC coefficient of the DQT along with the three neighboring DC coefficients within an 8x8 block are used to compute the next level DQT. Finally, the DC coefficients of the four 8x8 blocks within a 16x16 block are used to compute the DQT. Thus, in a 16x16 block, there is one true DC coefficient and the rest are AC coefficients corresponding to the DCT and DQT. [0060] The transform coefficients (both DCT and DQT) are provided to a quantizer for quantization. In a preferred embodiment, the DCT coefficients are quantized using frequency weighting masks (FWMs) and a quantization scale factor. A FWM is a table of frequency weights of the same dimensions as the block of input DCT coefficients. The frequency weights apply different weights to the different DCT coefficients. The weights are designed to emphasize the input samples having frequency content that the human visual or optical system is more sensitive to, and to deemphasize samples having frequency content that the visual or optical system is less sensitive to. The weights may also be designed based on factors such as viewing distances, etc. [0061] The weights are selected based on empirical data. A method for designing the weighting masks for 8x8 DCT coefficients is disclosed in ISO/IEC JTC1 CD 10918, "Digital compression and encoding of continuoustone still images  part 1: Requirements and guidelines," International Standards Organization, 1994, which is incorporated herein by reference. In general, two FWMs are designed, one for the luminance component and one for the chrominance components. The FWM tables for block sizes 2x2, 4x4 are obtained by decimation and 16x16 by interpolation of that for the 8x8 block. The scale factor controls the quality and bit rate of the quantized coefficients. [0062] Thus, each DCT coefficient is quantized according to the relationship: q Lfwm(i,j)*q 2. where DCT(i,j) is the input DCT coefficient, fwm(i j) is the frequency weighting mask, q is the scale factor, and DCTq(ij) is the quantized coefficient. Note that depending on the sign of the DCT coefficient, the first term inside the braces is rounded up or down. The DQT coefficients are also quantized using a suitable weighting mask. However, multiple tables or masks can be used, and applied to each of the Y, Cb, and Cr components. [0063] AC values are then separated 130 from DC values and processed separately. For DC elements, a first DC component value of each slice is encoded. Each subsequent DC component value of each slice is then represented as the difference between it and the DC component value preceeding it, and encoded 134. For lossless encoding, the initial DC component value of each slice and the differences are encoding 138 using GolombRice, as described with respect to FIGs. 6 and 8. Use of GolombRice encoding for the differences between successive DC component values is advantageous in that the differentials of the DC component values tend to have a twosided exponential distribution. The data may then be temporarily stored using a buffer 142, and then transferred or transmitted to the decoder 112 through the transmission channel 108. [0064] FIG. 8 illustrates a process of encoding DC component values. The process is equally applicable for still image, video image (such as, but not limited to, motion pictures or highdefinition television) and audio. For a given slice of data 804, a first DC component value of the slice is retrieved 808. The first DC component value is then coded 812. Unlike AC component values, the DC component values need not be quantized. In an embodiment, a single DC value for a 16x16 block is used regardless of the block size assignment breakdown. It is contemplated that any fixed sized block, such as 8x8 or 4x4, or any variable block size as defined by the block size assignment, may be used. The second, or next, DC component value of a given slice is then retrieved 816. The second DC component value is then compared with the first DC component value, and the difference, or residual, is encoded 820. Thus, the second DC component value need only be represented as the difference between it and the first value. This process is repeated for each DC component value of a slice. Thus, an inquiry 824 is made as to whether the end of the slice (last block and therefore last DC value) is reached. If not 828, the next DC value of the slice is retrieved 816, and the process repeats. If so 832, the next slice is retrieved 804, and the process repeats until all of the slices of a frame, and all of the frames of the file are processed. [0065] An objective of lossless encoding of DC component values is to generate resideual values that tend to have a low variance. In using DCTs, the DC coefficient component value contributes the maximum pixel energy. Therefore, by not quantizing the DC component values, the variance of the residuals is reduced. [0066] For AC elements, the block of data and frequency weighting masks are then scaled by a quantizer 146, or a scale factor element. Quantization of the DCT coefficients reduces a large number of them to zero which results in compression. In a preferred embodiment, there are 32 scale factors corresponding to average bit rates. Unlike other compression methods such as MPEG2, the average bit rate is controlled based on the quality of the processed image, instead of target bit rate and buffer status. [0067] To increase compression further, the quantized coefficients are provided to a scan serializer 150. The serializer 150 scans the blocks of quantized coefficients to produce a serialized stream of quantized coefficients. Zigzag scans, column scanning, or row scanning may be employed. A number of different zigzag scanning patterns, as well as patterns other than zigzag may also be chosen. A preferred technique employs 8x8 block sizes for the zigzag scanning. A zigzag scanning of the quantized coefficients improves the chances of encountering a large run of zero values. This zero run inherently has a decreasing probability, and may be efficiently encoded using Huffman codes. [0068] The stream of serialized, quantized AC coefficients is provided to a variable length coder 154. The AC component values may be encoded either using Huffman encoding or GolombRice encoding. For DC component values,, GolombRice encoding is utilized. A runlength coder separates the coefficients between the zero from the non¬zero coefficients, and is described in detail with respect to FIG. 6. In an embodiment, GolombRice coding is utilized. GolombRice encoding is efficient in coding nonnegative integers with an exponential distribution. Using Golomb codes is more optimal for compression in providing shorter length codes for exponentially distributed variables. [0069] In Golomb encoding runlengths, Golomb codes are parameterized by a non negative integer m. For example, given a parameter m, the Golomb coding of a positive integer n is represented by the quotient of nlm in unary code followed by the remainder represented by a modified binary code, which is \}og2 wijbits long if the remainder is less than 2^log2'"'m, otherwise, _log2 mjbits long. GolombRice coding is a special case of Golomb coding where the parameter m is expressed as m = 2*. In such a case the quotient of nlm is obtained by shifting the binary representation of the integer n to the right by k bits, and the remainder of nlm is expressed by the least k bits of n. Thus, the GolombRice code is the concatenation of the two. GolombRice coding can be used to encode both positive and negative integers with a twosided geometric (exponential) distribution as given by pa(x) = calxl (1) [0070] In (1), a is a parameter that characterizes the decay of the probability of x, and cis a normalization constant. Since pa(x) is monotonic, it can be seen that a sequence of integer values should satisfy pa(xl=0)>pa(xi =~l)>pa{Xi =+l)Zpa(x, =2)> (2) [0071] As illustrated in FIGS. 4a, 4b, 4c and 5a, 5b, 5c, both the zeroruns and amplitudes in a quantized DCT coefficient matrix have exponential distributions. The distributions illustrated in these figures are based on data from real images. FIG. 4a illustrates the Y component distribution 400 of zero runlengths versus relative frequency. Similarly, FIGs. 4b and 4c illustrates the Cb and Cr component distribution, of zero runlengths versus relative frequency 410 and 420, respectively. FIG. 5a illustrates the Y component distribution 500 of amplitude size versus relative frequency. Similarly, FIGs. 5b and 5c illustrates the Cb and Cr component distribution of amplitude size versus relative frequency, 510 and 520, respectively. Note that in FIGs. 5a, 5b, and 5c the plots represent the distribution of the size of the DCT coefficients. Each size represents a range of coefficient values. For example, a size value of four has the range {15,14, 8,8,...,14,15}, a total of 16 values. Similarly, a size value of ten has the range {1023,1022,,512,512,,1022,1023}, a total of 1024 values. It is seen from FIGs. 4a, 4b, 4c, 5a, 5b and 5c that both runlengths and amplitude size have exponential distributions. The actual distribution of the amplitudes can be shown to fit the following equation (3): P(X*.i) = ^exp{ j2X\xkl } k,I* 0 (3) In (3), Xkl represents the DCT coefficient corresponding to frequency k and I in the vertical and horizontal dimensions, respectively, and the mean jux ~ j=, variance a2x — —. Accordingly, the use of GolombRice coding in the manner described is more 2/1 optimal in processing data in DCTs. [0072] Although the following is described with respect to compression of image data, the embodiments are equally applicable to embodiments compressing audio data. In compressing image data, the image or video signal may be, for example, either in RGB, or YIQ, or YUV, or Y Cb Cr components with linear or log encoded pixel values. [0073] FIG. 6 illustrates the process 600 of encoding zero and nonzero coefficients. As the DCT matrix is scanned, the zero and nonzero coefficients are processed separately and separated 604. For zero data, the length of zero run is determined 608. Note that runlengths are positive integers. For example, if the runlength is found to be n, then a Golomb parameter m is determined 612. In an embodiment, the Golomb parameter is determined as a function of the run length. In another embodiment, the Golomb parameter (m) is determined by the following equation (4) w=flog2»"] (4) [0074] Optionally, the length of runlengths and associated Golomb parameters are counted 616 by a counter or register. To encode the run length of zeros n, a quotient is encoded 620. In an embodiment, the quotient is determined as a function of the run length of zeros and the Golomb parameter. In another embodiment, the quotient (jQ) is determined by the following equation (5): e=l«/2"J (5) In an embodiment, the quotient Q is encoded in unary code, which requires Q+l bits. Next, a remainder is encoded 624. In an embodiment, the remainder is encoded as a function of the run length and the quotient. In another embodiment, the remainder (R) is determined using the following equation (6): R = n~2mQ (6) In an embodiment, the remainder R is encoded in an mbit binary code. After, the quotient Q and the remainder R are determined, the codes for Q and R are concatenated 628 to represent an overall code for the run length of zeros n. [0075] Nonzero coefficients are also encoded using GolombRice. Since the coefficient amplitude can be positive or negative, it is necessary to use a sign bit and to encode the absolute value of a given amplitude. Given the amplitude of the nonzero coefficient being x, the amplitude may be expressed as a function of the absolute value of the amplitude and the sign. Accordingly, the amplitude may be expressed as y using the following equation (7): [ix, if x > 0 12 bc 1, otherwise [0076] Accordingly, the value of a nonzero coefficient is optionally counted by a counter, or register, 632. It is then determined 636 if the amplitude is greater than or equal to zero. If it is, the value is encoded 640 as twice the given value. If not, the value is encoded 644 as one less than twice the absolute value. It is contemplated that other mapping schemes may also be employed. The key is that an extra bit to distinguish the sign of the value is not needed. [0077] Encoding amplitudes as expressed by equation (7) results in that positive values of x being even integers and negative values become odd integers. Further, this mapping preserves the probability assignment of x as in (2). An advantage of encoding as illustrated in equation (7) allows one to avoid using a sign bit to represent positive and negative numbers. After the mapping is done, y is encoded in the same manner as was done for the zerorun. The procedure is continued until all coefficients have been scanned in the current block. [0078] It is important to recognize that although embodiments of the invention are determine values of coefficients and run lengths as a function of equations (1)  (7), the exact equations (l)(7) need not be used. It is the exploitation of the exponential distribution of GolombRice encoding and of DCT coefficients that allows for more efficient compression of image and audio data. [0079] Since a zerorun after encoding is not distinguishable from a nonzero amplitude, it may be necessary to use a special prefix code of fixed length to mark the occurrence of the first zerorun. It is common to encounter all zeros in a block after a nonzero amplitude has been encountered. In such cases, it may be more efficient to use a code referring to endofblock (EOB) code rather than GolombRice code. The EOB code is again, optionally, a special fixed length code. [0080] According to equation (1) or (3), the probability distribution of the amplitude or runlength in the DCT coefficient matrix is parameterized by a or A. The implication is that the coding efficiency may be improved if the context under which a particular DCT coefficient block arises. An appropriate GolombRice parameter to encode the quantity of interest may then be used. In an embodiment, counters or registers are used for each runlength and amplitude size value to compute the respective cumulative values and the corresponding number of times that such a value occurs. For example, if the register to store the cumulative value and number of elements accumulated are 7?r/and NH, respectively, the following equation (6) may be used as the RiceGolomb parameter to encode the runlength: (6) A similar procedure may be used for the amplitude. [0081] The residual pixels are generated by first decompressing the compressed data using the ABSDCT decoder, and then subtracting it from the original data. Smaller the residual dynamic range, higher is the compression. Since the compression is blockbased, the residuals are also generated on a block basis. It is a well known fact that the residual pixels have a twosided exponential distribution, usually centered at zero. Since GolombRice codes are more optimal for such data, a GolombRice coding procedure is used to compress the residual data. However, no special codes are necessary, as there are no runlengths to be encoded. Further, there is no need for an EOB code. Thus, the compressed data consists of two components. One is the component from the lossy compressor and the other is from the lossless compressor. [0082] When encoding motion sequences one can benefit from exploiting the temporal correlation as well. In order to exploit fully the temporal correlation, pixel displacement is first estimated due to motion, and then a motion compensated prediction is performed to obtain residual pixels. As ABSDCT performs adaptive block size encoding, block size information may be alternatively used as a measure of displacement due to motion. As a further simplification, no scene change detection is used. Instead, for each frame in a sequence first the intraframe compressed data is obtained. Then the difference between the current and previous frame DCTs, are generated on a block by block basis. These residuals in the DCT domain are encoded using both Huffman and GolombRice coding procedures. The final compressed output then corresponds to the one that uses the minimum number of bits per frame. [0083] FIG. 9 illustrates a hybrid lossless encoding apparatus 900. FIG. 10 illustrates a process that may be run on such an apparatus. Original digital information 904 resides on a storage device, or is transmitted. Many of the elements in FIG. 9 are described in more detail with respect to FIGs. 1 and 2. Frames of data are sent to a compressor 908, comprising a block size assignement element 912, a DCT/DQT transform element 916, a quantizer 920, and a serializer 921. After the DCT/DQT is performed on the data, the data is converted into the frequency domain. .In one output 922, the data is quantized by the quantizer 920 and transferred to an output 924, which may comprises storage and/or switching. All of the above described processing is intraframe. [0084] The quantizer output is also transferred to a decompressor 928. In another embodiment, the output of a serializer, such huffman serializer 921, is transferred to the decompressor. Optionally, the output of the serializer 921 may go through an inverse serializer (not shown) before the decompressor 928. The decompressor 928 undoes the process of the compressor, going through an inverse quantizer 932, and an 1DQT/IDCT 936, along with knowledge of the PQR data as defined by the BSA. The result of the decompressor 940 is fed to a subtracter 944 where it is compared with the original. The result 948 of the comparison between the decompressed data and the original is the pixel residual file. That is, the result 948 is indicative of the losses experienced by the data being compressed and uncompressed. Thus, the original data is equal to the output 922 in combination with the result 948. The result 948 is then serialized 952 and Huffman and/or Golomb Rice encoded 956, and provided as a second output 960. Thus, the lossless, interframe output is a combination, or hybrid of two sets of data, the lossy, high quality image file (922, or A) and the residual file (960 or C). [0085] Interframe coding may also be utilized. The output of the DCT/DQT 962 (not yet quantized, and therefore lossless) is transferred to a store 964, along with knowledge of the BSA. In an alternate embodiment, the output of the quantizer 963 (quantized, and therefore lossy) is transferred to the store 964, along with knowledge of the BSA. Upon gathering of a frame's worth of data, a subtracter 966 compares the stored frame 964 with a next frame 968. In an alternate embodiment the subtractor 966 compares on a block by block basis. The difference results in a DCT residual 970, which is then serialized and/or GolombRice encoded 974, providing a third output data set 976 to the output 924. Thus, an interframe lossless file of B and C is compiled. Thus, either combination (A+C or B+C) may be chosen based on size considerations. Further, a purely interframe output may be desirable for editing purposes. [0086] FIG. 11 illustrates a lossless decoder 1100, which operates in an equal but opposite manner as described with the encoder of FIG. 9. In FIG. 11, A represents interframe lossy compressed encoded data, B represents interframe residual lossy compressed encoded data, C represents iiitraframe lossy compressed encoded data and D represents intraframe residual lossy compressed encoded data. A is separated into DC coefficients 1104 and AC coefficients 1108. DC coefficients 1104 are decompressed and the values are retrieved in a manner as described in FIG. 8 and pending US Patent Application entitled "Lossless Interframe Encoding Using GOLOMBRICE", filed July 2, 2001, Serial No. 09/898,284, which is specifically incorporated by reference herein. More specifically, the DC coefficients 1104 are transferred to a GolombRice decoder 1112, which reverses the function of the GolombRice encoder and transfers the output to an inverse DC differential pulse code modulator (IDCDPCM) 1116. The IDCDPCM 1116 determines the DC component values and transfers them to an Inverse Discrete Cosine Transform (JDCT) 1120. Similarly, the AC coefficients 1108 are transferred to an inverse serializer 1124. In an embodiment, the inverse serializer is an inverse huffman serializer. The output of the serializer 1124 is transferred to an inverse quantizer 1128, whose output is transferred to the IDCT 1120. The IDCT 1120 decompressed by performing an inverse transform producing lossy decompressed frequency data. [0087] Input B represents interframe residual lossy compressed encoded data, which is transferred to a GolombRice decoder 1132. The GolombRice decoder 1132 reverses the function of the GolombRice encoder and transfers the output to an adder 1136. The adder 1136 adds the residual output with the output of the IDCT 1120 to produce lossless, interframe encoded data in the frequency domain. A color transformer 1140 coverts this back to the RGB form for final output. Different variations of color transforms may be utilized, such as those described in provisional patent application entitled "ABSDCT Lossless Algorithm for Digital Cinema Archival Applications filed July 11,2002, Attorney Docket No. 010421. [0088] Interframe decoding operates in a similar manner. Input C represents lossy interframe compressed encoded data, which is transferred to a GolombRice decoder 1144. Data output from the GolombRice decoder 1144 is differential DCT data, representing the differences between elements between the current frame and the previous frame. A store 1148 stores data from the previous frame, and is added with to the DCT differentials by an adder 1152 resulting in lossy data in the DCT domain. Then, the lossy data in the DCT domain is transferred to an inverse quantizer 1156, whose output is transferred to the IDCT 1160. The IDCT 1120 decompressed by performing an inverse transform producing lossy decompressed frequency data. The output of the inverse quantizer 1156 is also transferred to the store 1148 to serve as previous frame of data that will be compared against the next frame of data. [0089] Input D represents intraframe residual compressed encoded data, which is transferred to a GolombRice decoder 1164. The GolombRice decoder 1164 reverses the function of the GolombRice encoder and transfers the output to an adder 1168. The adder 1136 adds the residual output with the output of the IDCT 1160 to produce lossless, intraframe encoded data in the frequency domain. A color transformer 1172 coverts this back to the RGB form for final output. [0090] Referring back to FIG. 1, the compressed image signal generated by the encoder 104 may be temporarily stored using a buffer 142, and then transmitted to the decoder 112 using the transmission channel 108. The transmission channel 108 may be a physical medium, such as a magnetic or optical storage device, or a wireline or wireless conveyance process or apparatus. The PQR data, which contains the block size assignment information, is also provided to the decoder 112 (FIG. 2). The decoder 112 comprises a buffer 164 and a variable length decoder 168, which decodes the runlength values and the nonzero values. The variable length decoder 168 operates in a similar but opposite manner as that described in FIG. 6. [0091] The output of the variable length decoder 168 is provided to an inverse serializer 172 that orders the coefficients according to the scan scheme employed. For example, if a mixture of zigzag scanning, vertical scanning, and horizontal scanning were used, the inverse serializer 172 would appropriately reorder the coefficients with the knowledge of the type of scanning employed. The inverse serializer 172 receives the PQR data to assist in proper ordering of the coefficients into a composite coefficient block. [0092] The composite block is provided to an inverse quantizer 174, for undoing the processing due to the use of the quantizer scale factor and the frequency weighting masks. [0093] The coefficient block is then provided to an IDQT element 186, followed by an IDCT element 190, if the Differential Quadtree transform had been applied. Otherwise, the coefficient block is provided directly to the IDCT element 190. The IDQT element 186 and the IDCT element 190 inverse transform the coefficients to produce a block of pixel data. The pixel data may then have to be interpolated, converted to RGB form, and then stored for future display. [0094] FIG. 7 illustrates an apparatus for GolombRice encoding 700. The apparatus in FIG. 7 preferably implements a process as described with respect to FIG. 6. A determiner 704 determines a run length (n) and a Golomb parameter (m). Optionally, a counter or register 708 is used for each runlength and amplitude size value to compute the respective cumulative values and the corresponding number of times that such a value occurs. An encoder 712 encodes a quotient (Q) as a function of the run length and the Golomb parameter. The encoder 712 also encodes the remainder (R) as a function of the run length, Golomb parameter, and quotient. In an alternate embodiment, encoder 712 also encodes nonzero data as a function of the nonzero data value and the sign of the nonzero data value. A concatenator 716 is used to concatenate the Q value with the R value. [0095] As examples, the various illustrative logical blocks, flowcharts, and steps described in connection with the embodiments disclosed herein may be implemented or performed in hardware or software with an applicationspecific integrated circuit (ASIC), a programmable logic device, discrete gate or transistor logic, discrete hardware components, such as, e.g., registers and FIFO, a processor executing a set of firmware instructions, any conventional programmable software and a processor, or any combination thereof. The processor may advantageously be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The software could reside in RAM memory, flash memory, ROM memory, registers, hard disk, a removable disk, a CDROM, a DVDROM or any other form of storage medium known in the art. [0096] The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. The various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [0097] Other features and advantages of the invention are set forth in the following claims. WE CLAIM: 1. A method of decoding data representing an original image, the method comprising: receiving lossy compressed data; receiving quadtree (PQR) data that define blocks of pixels, said blocks of pixels having various sizes and said blocks of pixels having been generated by adaptively block sizing the original image; separating the lossy compressed data into DC data and AC data; decoding, separately, the DC data to determine DC coefficients and the AC data to determine AC coefficients, wherein the PQR data are used to determine the AC coefficients; inverse quantizing the AC coefficients; inverse transforming the DC coefficients and the inverse quantized AC coefficients to produce lossy decompressed data that can be used to reproduce an image similar to the original image; receiving residual compressed data; decoding the residual compressed data to produce aresidual decompressed data; and combining the lossy decompressed data with the residual decompressed data to produce lossless data, wherein an image reproduced usingjhe lossless data is substantially the same as the original image. 2. The method as claimed in claim 1, wherein the lossy compressed data and the residual compressed data are decoded on an intraframe basis. 3. The method as claimed in claim 1, wherein the lossy compressed data and the residual compressed data are decoded on an interframe basis. 4. The method claimed in claim 1, wherein inverse transforming utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques or DCT technique. 5. The method claimed in claim 1, comprising transforming the lossless data into red, green, blue (RGB) color components. 6. The method as claimed in claim 1, comprising inverse serializing the AC coefficients by at least using the PQR data to order the AC coefficients into a coefficient block. 7. The method as claimed in claim 1, wherein decoding comprises using a Golomb decoder to decode the AC values and further wherein Golomb decoding is based on a parameter m being determined as a function of the PQR data. 8. The method as claimed in claim 1, wherein decoding comprises using a GolombRice decoder to decode the AC values and further wherein GolombRice decoding is based on a parameter m being determined as a function of the PQR data. 9. The method as claimed in claim 1, wherein the residual compressed data are generated by comparing the original image and a reproduced image, wherein the lossy compressed data are used to obtain the reproduced image. 10. The method as claimed in claim 1, wherein decoding the residual compressed data further comprises using the PQR data to decode the residual compressed data. 11. An apparatus for decoding data representing an original image, the apparatus comprising: a receiver configured to receive a lossy compressed data and quadtree (PQR) data that define blocks of pixels, said blocks of pixels having various sizes and said blocks of pixels having been generated by adaptively block sizing the original image, wherein said receiver is configured to receive residual compressed data; a separator coupled to the receiver configured to separate the lossy compressed data into DC data and AC data; a decoder coupled to the separator configured to separately code the DC data to determine DC coefficients and the AC data to determine AC coefficients, wherein the PQR data are used to determine the AC coefficients, wherein said decoder is configured to decode the residual compressed data to produce residual decompressed data; an inverse quantizer coupled to the decoder configured to inverse quantize the AC coefficients; an inverse transformer coupled to the decoder and the inverse quantizer configured to inverse transform the DC coefficients and the inverse quantized AC coefficients to produce lossy decompressed data that can be used to reproduce an image similar to the original image; and an adder configured to combine the lossy, decompressed data with the residual decompressed data to produce lossless data, wherein an image reproduced using the lossless data is substantially the same as the original image. 12. The apparatus as claimed in claim 11, wherein the lossy compressed data and the residual compressed data are decoded on an intraframe basis. 13. The apparatus as claimed in claim 11, wherein the lossy compressed data and the residual compressed data are decoded on an interframe basis. 14. The apparatus claimed in claim 11, wherein the inverse transformer utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques or DCT technique. 15. The apparatus claimed in claim 11, comprising a transformer coupled to the combiner configured to convert the lossless data into red, green, blue (RGB) color components. 16. The apparatus as claimed in claim 11 comprising and inverse serializer for inverse serializing the AC coefficients by at least using the PQR data to order the AC coefficients into a coefficient block. 17. The apparatus as claimed in claim 11, wherein said decoder comprises a Golomb decoder to decode the AC values and further wherein the Golomb decoder uses a parameter m being determined as a function of the PQR data. 18. The apparatus as claimed in claim 11, wherein said decoder comprises a GolombRice decoder to decode the AC values and further wherein the GolombRice decoder uses a parameter m being determined as a function of the PQR data. 19. The apparatus as claimed in claim 11, wherein the residual compressed data are generated by comparing the original image and a reproduced image, wherein the lossy compressed data are used to obtain the reproduced image. 

0104chenp2004 abstractduplicate.pdf
0104chenp2004 claimsduplicate.pdf
0104chenp2004 correspondences others.pdf
0104chenp2004 correspondences po.pdf
0104chenp2004 description (complete)duplicate.pdf
0104chenp2004 description (complete).pdf
0104chenp2004 drawingsduplicate.pdf
0104chenp2004 pct search report.pdf
Patent Number  230090  

Indian Patent Application Number  104/CHENP/2004  
PG Journal Number  13/2009  
Publication Date  27Mar2009  
Grant Date  24Feb2009  
Date of Filing  19Jan2004  
Name of Patentee  QUALCOMM INCORPORATED  
Applicant Address  5775 MOREHOUSE DRIVE, SAN DIEGO, CALIFORNIA 92121,  
Inventors:


PCT International Classification Number  H04N 7/26  
PCT International Application Number  PCT/US02/22863  
PCT International Filing date  20020719  
PCT Conventions:
