Abstract: A coding method, apparatus, and storage media with instructions to carry out a method. The method operates on an ordered series of transform coefficients of a block of image data, and for a fixed quantization method, and includes quantizing and encoding the ordered series to form a coded bitstream. The quantizing and encoding uses one or more variable length code (VLC) mappings. The quantizing includes quantizing to have amplitude-1 at least one coefficient that would be quantized by the fixed quantization method to have zero amplitude, quantizing to have zero amplitude at least one coefficient that would be quantized by the fixed quantization method to have amplitude-1, and using the fixed quantization method to quantize any coefficient that is quantized by the fixed quantization method not to have zero amplitude, amplitude-1, or amplitude-2.

Abstract: An image decoding method, apparatus and program for decoding coded picture data is disclosed. In the method, apparatus and program, the coded picture data is entropy-decoded to derive four transform coefficient strings each comprising entropy-decoded sixteen (16) transform coefficients. The four transform coefficient strings are combined into an 8×8 block of entropy-decoded sixty four (64) transform coefficients by de-interleaving the four strings in such a manner as to select a lower frequency transform coefficient alternately from the four strings and arrange it in the 8×8 block in an order of a low frequency to a high frequency. An inverse orthogonal transform is then performed on the 8×8 block of the entropy-decoded sixty four (64) transform coefficients.

Abstract: In order to reduce wasteful operation processes by operation units, a data supply unit reads out a plurality of pieces of pixel data from an image memory and temporarily stores the pixel data in registers, and outputs the pixel data while shifting the pixel data in one direction; product-sum operators concurrently perform operation processes based on multiple pieces of pixel data outputted from the data supply unit and filter coefficients in a filter kernel. At this time, a selector within the data supply unit selects the pixel data stored in each register in accordance with the type of the filter operation process, and outputs the selected pixel data to the product-sum operators.

Abstract: Data can be transferred from a picture processing section to an encoding section without necessity of using an external memory. In addition, with internal data transfer having a wider band than an external memory, data can be processed at high speed. An entire picture 41 as an original picture is divided into six blocks of (64×4) pixels each. An enlargement process is performed for each block. Data of blocks are read in the order of blocks 1, 2, 3, and so forth. A size changing section processes a first block and generates picture data of a block 42 of (128×8) pixels. From this picture data 42, macroblocks 43 of (16×8) pixels each are read and encoded. As a result, JPEG data 44 are obtained. A code rearrangement section rearranges the order of the JPEG data 46 in the unit of a block. As a result, JPEG data 48 are generated. When JPEG data 48 are decoded in this order, a decoded picture 49 whose block order matches an area 41 of the original picture is obtained.

Abstract: A method for representing video data related to a macroblock of a video image in a coding procedure wherein certain, video data or combinations of video data is represented in predefined events associated with indexed positions in a Variable Length Code (VLC) table including codes assigned to each indexed position, including: determining, with a processor, that a first event among said predefined events occurs during the coding procedure; coding, with the processor, the first event with a code assigned to a position x in the VLC table being associated with the first event, the VLC table being stored in a memory device; determining, with the processor, whether x>0, wherein 0 denotes a position at a top of the VLC table; and rearranging, with the processor, the VLC table by associating a second event currently associated with a position x?1 with the position x, and associating the first event with the position x?1.

Abstract: Methods, medium, and handheld, wireless devices which compress, enhance, encode, transmit, decompress and display digital video images in real time. Real time wireless videoconferences connect multiple handheld video devices. Real time compression is achieved by sub-sampling each frame of a video signal, filtering the pixel values, and encoding. Real time transmission is achieved due to high levels of effective compression. Real time decompression is achieved by decoding and decompressing the encoded data to display high quality images. A receiver can alter various setting including but not limited to the format for the compression, image size, frame rate, brightness and contrast. A zoom control can be used select a portion of interest of video being transmitted or being played back.

Abstract: An image encoding device that encodes an image by performing sequential processing in units of a certain size, the image encoding device includes, a variable-length coding unit that performs variable-length coding on data to be encoded having the certain size in the image; an estimating unit that estimates the number of codes at a time after the variable-length coding using the data to be encoded at a time before the variable-length coding is performed by the variable-length coding unit; and a slice controlling unit that controls division of the image into slices on the basis of a cumulative value of the estimated number of codes.

Abstract: A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure.

Abstract: An optimized method and system to generate a compressed image utilizing custom probability tables are described. The system may include a input module to receive a digital image, a sample generator to generate a representative sample image from the input image, a custom probability tables generator to generate custom probability tables and an entropy coder to encode the input image utilizing the custom probability tables. The custom probability tables generator may be configured to generate custom probability tables utilizing the representative sample image.

Abstract: An optimized method and system for entropy coding is described. The system may include an input module to receive a digital image, a Discrete Cosine Transform (DCT) module to obtain a plurality of DCT coefficients associated with the digital image, a statistics generator to generate statistics associated with the plurality of DCT coefficients, a placement module to store the generated statistics in the plurality of DCT coefficients and entropy coder to generate uniquely decodable (UD) codes for the plurality of DCT coefficients. The entropy coder may utilize the statistics stored in the plurality of DCT coefficients.

Abstract: A variable length encoding (VLE) device of an image compression system is suitable for encoding transformed and quantized block image signals. The VLE device includes a plurality of encoding modules, for performing VLE on the block image signals; and a selection module (VLE module start controller), for selecting a number of the encoding modules in turn to encode the block image signals. The encoding modules are configured for parallel processing, and an operating frequency of each of the encoding modules is a fractional frequency of a throughput rate of the image compression system. The VLE device is not affected by the time consumed by the VLE in the image compression process, and enables the entire image compression system to operate as desired and achieve the required throughput rate.

Abstract: The image data processor generates storage layout information and output joint information, and then generates a page raster for storage based on the storage layout information and a page raster for output based on the output joint information. The storage layout information is based on layout information describing object layouts and includes a page formed by the same objects and reusable objects of the same arrangements and a page formed by each variable object. The output joint information combines a page for reusable objects and a page for the variable object.

Abstract: Lossless video data compression is performed in real time at the data rate of incoming real time video data in a process employing a minimum number of computational steps for each video pixel. A first step is to convert each pixel 8-bit byte to a difference byte representing the difference between the pixel and its immediate predecessor in a serialized stream of the pixel bytes. Thus, each 8-bit pixel byte is subtracted from its predecessor. This step reduces the dynamic range of the data. A next step is to discard any carry bits generated in the subtraction process of two's complement arithmetic. This reduces the data by a factor of two. Finally, the 8-bit difference pixel bytes thus produced are subject to a maximum entropy encoding process. Such a maximum entropy encoding process may be referred to as a minimum length encoding process. One example is Huffman encoding.

Abstract: Particular embodiments include a method, an apparatus, and logic embodied in tangible computer-readable medium that when executed carries out a method of encoding an ordered sequence of quantized transform coefficients of a block of image data. One embodiment is a context adaptive variable length coding method that includes position coding the positions of zero-valued and non-zero valued coefficients by either a mixed method that encodes either the run length of zeroes preceding a non-zero coefficient or the run length of nonzero-valued coefficients preceding a zero-valued coefficients. Another includes position coding that uses a variable length code for two parameters respectively indicating the number of zero-valued coefficient positions and nonzero-valued coefficient positions still to be coded.

Abstract: In one embodiment, an initial series of bytes are scanned to determine a frequency of occurrence within the initial series of bytes for a plurality of byte strings. A data structure is generated containing the plurality of byte strings and count values representing a frequency of occurrence for the plurality of byte strings in the initial series of bytes. A most common byte string of the plurality of byte strings in the initial series of bytes is determined from the count values. Each instance of the most common byte string in the initial series of bytes is replaced with a first substitute byte string to form a revised series of bytes. A most common byte string in the revised series of bytes is determined from the data structure without resetting the count values associated with at least some of the plurality of byte strings.

Abstract: A computer-assisted inspection system provides customized workflow based on different types of inspections and other factors. The system can provide different rules that can be activated in response to valuation/pricing, rule-based validation and automatic grading. Features include flat car part picking, easy to use, inspectors can be geographically separated, and system is installable over the internet to provide efficient installation to far-flung install sites.

Abstract: A coding device is comprised of an initial resolution coding unit for coding an initial resolution image sub-sampled from an image at every interval of predetermined pixels, and a high resolution coding unit for coding images at sub-sampling intervals sequentially halved, wherein said high resolution coding unit comprises a pixel value predicting means for, out of the pixels that should be coded in present resolution, predicting a value of a pixel being positioned at a center of its adjacent four pixels already coded in previous resolution from said adjacent four pixels with a linear interpolation, and predicting a value of a remaining pixel from its adjacent four pixels having the above pixel at a center thereof with the linear interpolation, said adjacent four pixels being positioned in an upper, lower, left and right sides of the above pixel, a prediction error calculating means for obtaining a residual between the pixel value of the to-be-coded pixel and the predicted value, and a variable length coding m

Abstract: An image coding method is disclosed by which plural code data sets each having a different code amount are generated from one image data set that includes a target code amount setting step for setting a different target code amount for each of the code data sets; an entropy code generation step for applying entropy coding processing to the image data set or data obtained by applying predetermined processing to the image data set so as to generate plural entropy codes; a code amount control step for specifying one of the entropy codes to be truncated so as to control a code amount for each different target code amount; and a code data generation step for truncating the one of the entropy codes specified in the code amount control step and generating the corresponding code data set.

Abstract: A method comprises determining a plurality of time intervals Tp and Tn within a variable bit rate (VBR) representation of an image sequence. The time intervals Tp are those in which a number of blocks of information per unit time is greater than a baseline value. The time intervals Tn are those in which a number of blocks of information per unit time is less than the baseline value. A second representation of the image sequence is created in which some blocks of information Bp are removed from the time intervals Tp and interlaced with blocks of information Bn in the time intervals Tn to reduce a variation in a number of blocks of information per unit time between the time intervals Tp and Tn.

Abstract: A coding method for an ordered series of quantized transform coefficients of a block of image data, including a context adaptive position coding process to encode the position of clusters of non-zero-valued coefficients, e.g., a multidimensional position coder that uses one of a plurality of code mappings selected according to at least one criterion including at least one context-based criterion, and an amplitude encoding process to encode any amplitudes remaining to be coded, the amplitude coding using one or a plurality of amplitude code mappings selected according to at least one criterion, including a context-based criterion. A context-based selection criterion is meant a criterion that during encoding is known or derivable from one or more previously encoded items of information. Also a coding apparatus, a decoding apparatus, a computer readable medium configured with instructions that when executed implement a coding method, and another medium for a decoding method.

Abstract: A method of image compressing is provided. During compressing, color intensity of the image is considered. When the color intensity of the image is relatively high, lower bits used for representing the image are dropped. When the color intensity of the image is relatively low, upper bits used for representing the image are dropped. By this, the image is compressed according to color intensity of the image. Therefore, the images with different color intensities are compressed dynamically. Correspondingly, a method of image decompressing is provided. Moreover, a compressing apparatus and a decompressing apparatus are also provided.

Abstract: A data processing apparatus includes a motion vector storage unit, an index value generating unit, a storage control unit, and a motion vector reading unit. The motion vector storage unit stores a motion vector in a unit block area. The index value generating unit generates the index value corresponding to a position of the unit block at upper left and upper right corners of an object block for which a prediction motion vector is to be acquired, on the basis of a size of the object block. The storage control unit copies a motion vector of an adjacent block by each of the unit block area and stores the copied motion vector. The motion vector reading unit obtains the index value indicating the unit block area on the basis of the index value. The prediction motion vector is obtained on the basis of the motion vector.

Abstract: An imaging system comprises: an imaging unit for producing an image within a given field of view; an image defect detector for detecting a defective area from a first image that is produced by the imaging unit without a subject in the given field of view; a size enlarging unit for forming a deemed defective area having an enlarged size consisting of pixels of the first image corresponding to a defective area detected by the image defect detector and at least one of pixels adjacent to these pixels; and an image defect correcting unit for correcting a second image produced by the imaging unit with a subject located within the given view of field according to a deemed defective area formed by the size enlarging unit.

Abstract: A method and system are provided for compressing and/or decompressing a set of dot-matrix font characters. According to a compression method, each dot-matrix font character is divided into a horizontal image including horizontal (stroke) image pattern(s), a vertical image including vertical (stroke) image pattern(s), and a residual image including residual image pattern(s) obtained by removing the horizontal and vertical images from the original character. Then, the Huffman coding is applied to each of a set of the horizontal image patterns, a set of the vertical image patterns, and a set of the residual image patterns, respectively, to produce compressed horizontal codes for the horizontal image patterns in a horizontal Huffman table, compressed vertical codes for the vertical image patterns in a vertical Huffman table, and compressed residual codes for the residual image patterns in a residual Huffman table.

Abstract: A method for transcoding a first codeword to a second codeword, wherein both comprise escape codes and escape levels is disclosed. The method comprises receiving a bitstream to determine the first codeword therefrom, determining whether the first codeword belongs to a long escape mode or a short escape mode, and truncating the escape level of the first codeword to generate the second codeword when the first codeword belongs to the long escape mode. An embodiment of the first codeword is a Sorenson H.263 codeword and the second codeword is an H.263 codeword.

Abstract: Techniques and tools for encoding and decoding a block of frequency coefficients are presented. An encoder selects a scan order from multiple available scan orders and then applies the selected scan order to a two-dimensional matrix of transform coefficients, grouping non-zero values of the frequency coefficients together in a one-dimensional string. The encoder entropy encodes the one-dimensional string of coefficient values according to a multi-level nested set representation. In decoding, a decoder entropy decodes the one-dimensional string of coefficient values from the multi-level nested set representation. The decoder selects the scan order from among multiple available scan orders and then reorders the coefficients back into a two-dimensional matrix using the selected scan order.

Abstract: A drawing apparatus which can create an exposure pattern rapidly. The drawing apparatus has a raster conversion processing module for converting vector images as wiring patterns into bitmap image data, an image cache module for temporarily storing a predetermined-size cached image supplied from the raster conversion processing module, a first compression module for compressing the cached image stored in the image cache module, a second compression module for compressing the cached image stored in the image cache module in a compression ratio differing from that of the first compression module, a comparison module for comparing data sizes of compressed data generated by the first and second compression modules and selecting one having a smaller data size, a memory access module for writing the compressed data selected by the comparison module, into a storage module, and a cache region control module for controlling a compression status of the cached image.

Abstract: A method for estimating quality of images compressed with a transformation based compression method. The estimation method uses estimated errors generated by quantization to obtain an image quality indicator and does not require use of a reference image. The estimation method includes calculating a probability of at least one specific quantized transformation coefficient value for at least all coefficients representing one identical two-dimensional frequency, and estimating identifying parameters of at least one probability density function of non-quantized coefficient values from the quantized coefficient value probabilities, with a type of probability density function being preset. The estimation method further includes calculating an image quality indicator from errors introduced by quantization, which are derived from probability density function parameters and quantization parameters.

Abstract: A system (and a method) are disclosed for optimizing lossless data compression in digital images systems iteratively. The system includes a backward reference module and an entropy encoder. The backward reference module comprises three sub-modules: a backward reference selection module, a backward reference statistics measurement module and a backward reference selection control module. The backward reference selection module initially selects backward references that have shorter backward distances. The statistics measurement module analyzes the backward references of input data. The backward reference selection module updates the backward references based on the statistics of previously generated backward references at subsequent selection iterations. The backward reference selection control module controls the number of selection iterations needed for optimized data compression performance.

Abstract: A system and method for updating a display unit remotely located from a computing system are described. The method includes copying display information from a video buffer of a computing device executing an application to generate a display update, calculating a size of the display update, and determining an amount of available bandwidth of a network connecting the computing device and the display unit. The method also includes calculating a time period required to communicate the display update from the computing device to the display unit, transmitting the display update to the display; and repeating the method after the time period has elapsed.

Abstract: An apparatus and a method generate a coded block pattern (CBP) of an alpha channel image. An apparatus and a method encode or decode the alpha channel image using the method. The alpha channel image encoding apparatus includes a CBP generator generating a CBP of a first block corresponding to an encoding unit in the alpha channel image by allocating CBPs to a plurality of second blocks that includes the first block; and a bitstream generator generating a bitstream by encoding the CBP or the CBP and pixel values of the second blocks based on the CBP of each of second blocks.

Abstract: Data of both MPEG-2 and MPEG-4 is generated simultaneously with a small circuit scale and a small power consumption. A moving picture encoding apparatus for encoding a moving picture through motion-compensated inter-frame prediction has: a MPEG-2 encoding unit including a motion vector estimator, a frame memory, a forward prediction circuit, a bidirectional prediction circuit, a prediction selection circuit, an intra-frame encoding circuit and a local decoding circuit; a MPEG-4 encoding unit including a frame extraction circuit for extracting a predetermined MPEG-2 frame and a transcoder for encoding the extracted frame; a motion vector calculator calculating a motion vector to be used for MPEG-4 prediction from a motion vector to be used for MPEG-2 prediction; and a prediction mode controller controlling the prediction mode of the MPEG-2 encoding unit in such that the MPEG-2 prediction mode becomes coincident with the MPEG-4 prediction mode.

Abstract: A variable bit rate (VBR) representation of an image sequence is segmented based on a plurality of time intervals. For each of at least two of the time intervals, the method comprises: determining which of the packets, denoted by Pp, in the VBR representation within the presently-considered time interval has a number of blocks of information per unit time greater than a baseline value; determining which of the packets, denoted by Pn, in the VBR representation within the presently-considered time interval has a number of blocks of information per unit time less than the baseline value; and creating a second representation of the image sequence in which some blocks of information Bp are removed from at least one Pp packet and interlaced with blocks of information in at least one Pn packet to produce reformatted packets.

Abstract: A method for decoding a binary image at a high speed, wherein blocks having same pixel values are decoded in clock units, such that a decoding speed increases. The method includes: determining whether a predetermined number of sequential pixels corresponds to any one of a white_run, a black_run, and a combined_run; and if the predetermined number of sequential pixels corresponds to any one of the white_run, the black_run, and the combined_run, decoding the sequential pixels in a block per clock unit.

Abstract: A system (and a method) are disclosed for optimizing lossless data compression in digital images systems. The system includes an optimized backward reference selection module and an entropy encoder. The optimized backward reference selection module selects the backward references that the backward reference distances and/or lengths are an integer multiple of size of data elements. The optimized backward reference selection module further compacts the entropy code of the backward references by favoring backward references that have the intrinsic locality of source data stream. The optimization offered by the backward reference selection module allows an improved compression ratio and faster compression speed for lossless image compression.

Abstract: An image compression unit includes a block divider that divides image data into a plurality of blocks, a DCT portion that subjects the image data of each block to DCT, a quantization factor output portion that outputs a quantization factor as a numerical value indicative of fineness of quantization, a correction value computation portion that computes a correction value that is determined uniquely according to a position of a block of image data, a quantizer that quantizes the data having been subjected to DCT, based on a value obtained by multiplying the correction value by the quantization factor, and an encoder that encodes the quantized data and outputs compressed data. This configuration makes it possible to provide an image compression/decompression unit that is capable of varying a compression ratio in a frame, without encoding compression parameters of each block.

Abstract: A method and an arrangement for improving the digital-signal-generated grayscale resolution of a monochrome visual display unit (3) to which the digital signals from an image source (1) can be supplied over n-bit wide RGB channels (2). Measures are proposed that make it possible to display distinguishable grayscale gradations on the visual display unit (3) regardless of whether a grayscale signal (6; 10) or RGB color signals (12, 13, 14) are transmitted to the visual display unit (3).

Abstract: A method for transcoding from an MPEG-2 format to an H.264 format is disclosed. The method generally comprises the steps of (A) decoding an input video stream in the MPEG-2 format to generate a plurality of macroblocks; (B) determining a plurality of indicators from a pair of the macroblocks, the pair of the macroblocks being vertically adjoining; and (C) coding the pair of the macroblocks into an output video stream in the H.264 format using one of (i) a field mode coding and (ii) a frame mode coding as determined from the indicators.

Abstract: The present invention relates to an image processing method and apparatus for processing compressed image generated by segmenting image data into a plurality of MCUs and using a compression method in which a frequency transformation is applied to each MCU. In a case that the compressed image is decoded, each MCU is classified according to the frequency coefficients therein, and color separated data is generated for each MCU based on the decoded data resulting from the decoding and the results of the MCU classification.

Abstract: Particular embodiments include a method, an apparatus, and logic embodied in tangible computer-readable medium that when executed carries out a method of encoding an ordered sequence of quantized transform coefficients of a block of image data. One embodiment is a context adaptive variable length coding method that includes position coding the positions of zero-valued and non-zero valued coefficients by either a mixed method that encodes either the run length of zeroes preceding a non-zero coefficient or the run length of nonzero-valued coefficients preceding a zero-valued coefficients. Another includes position coding that uses a variable length code for two parameters respectively indicating the number of zero-valued coefficient positions and nonzero-valued coefficient positions still to be coded.

Abstract: A method for transcoding from an H.264 format to an MPEG-2 format is disclosed. The method generally comprises the steps of (A) decoding an input video stream in the H.264 format to generate a picture having a plurality of macroblock pairs that used an H.264 macroblock adaptive field/frame coding; (B) determining a mode indicator for each of the macroblock pairs; and (C) coding the macroblock pairs into an output video stream in the MPEG-2 format using one of (i) an MPEG-2 field mode coding and (ii) an MPEG-2 frame mode coding as determined from the mode indicators.

Abstract: An apparatus includes at least one general purpose register and at least one special purpose register and an execution unit that executes at least two instructions in parallel, to decode variable length codes, wherein each of the instructions share use of the at least one general purpose register and the at least one special purpose register. In one example, a processor stores variable length code information among a plurality of general purpose registers and generates decoded variable length code information by decoding the at least one variable length code. The processor also stores the decoded variable length code information among the plurality of general purpose registers.

Abstract: A method and apparatus for coding an image by using exponential Golomb binarization are provided. The method comprises: performing entropy coding on an input image by performing exponential Golomb binarization using a plurality of predetermined thresholds; measuring a bit rate of a bit stream which is generated by performing the entropy coding using each threshold; and determining an optimal threshold by comparing bit rates with regard to the thresholds.

Abstract: Coding quantized transform coefficients as occur in image compression combines a position identifying method to identify the relative position of clusters of consecutive non-zero-valued coefficients, an amplitude event identifying method to identify amplitude events in the clusters of non-zero-valued coefficients, and a coding method to code the position events, amplitude events, and signs of the amplitudes in the clusters. The method is particularly applicable to a series of quantized transform coefficients where clusters are likely-to-occur.

Abstract: A series of decoded images is generated from a series of original images encoded by a first encoding technique following movement-compensated, predictive encoding, where a starting image of a group of successive original images that are to be encoded is defined by a second encoding technique following movement-compensated, temporally filtered partial band encoding based on a determined encoding property of a decoded image of the group of images that are to be encoded, the decoded image is used for generating an output image having a low resolution level, before the images are encoded. At least one output image is generated on each level of resolution from the successive original images of the group of from at least one decoded image during image encoding. The decoded images are provided only with a reduced quality while the reconstituted images are of great quality.

Abstract: A VSB communication system or transmitter for processing supplemental data packets with MPEG-II data packets includes a VSB supplemental data processor and a VSB transmission system. The VSB supplemental data processor includes a Reed-Solomon coder for coding the supplemental data to be transmitted, a null sequence inserter for inserting a null sequence to an interleaved supplemental data for generating a predefined sequence, a header inserter for inserting an MPEG header to the supplemental data having the null sequence inserted therein, a multiplexer for multiplexing an MPEG data coded with the supplemental data having the MPEG header added thereto in a preset multiplexing ratio and units. The output of the multiplexer is provided to an 8T-VSB transmission system for modulating a data field from the multiplexer and transmitting the modulated data field to a VSB reception system.

Abstract: A method, and apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method. The method is to code a plurality of ordered sequences of quantized transform coefficients of a corresponding plurality of blocks of image data using a hybrid coding method that includes determining a breakpoint location in the sequence between a low frequency region and a high frequency region; coding the low-frequency region using a selected low-frequency variable length coding method; coding the high-frequency region using a selected high-frequency variable length coding method; and coding the location of the breakpoint. The plurality of blocks include adjacent blocks and form a multi-block partition. The breakpoint location is determined as a function of the sequences of the multi-block partition such that different multi-block partitions can have different breakpoints.

Abstract: Exemplary methods, computer systems, and computer program products for processing a previously compressed data stream in a computer environment are provided. In one embodiment, the computer environment is configured for separating a previously compressed data stream into an input data block including a header input block having a previously compressed header. Sequences of bits are included with the input data block. Compression scheme information is derived from the previously compressed header. The input data block is accessed and recompressed following the header input block in the previously compressed data stream one at a time using block-image synchronization information. Access to the block-image synchronization information is initialized by the compression scheme information to generate an output data block. The block-image synchronization information is used to provide decompression information to facilitate decompression of the results of the output data block.

Abstract: A method and an apparatus for compressing or decompressing two-dimensional electronic data are provided. The method for compressing the two-dimensional electronic data set includes dividing the data set into data arrays, performing a wavelet transformation on each array to provide a plurality of wavelet coefficients, and encoding at least some of the wavelet coefficients using an entropy encoding scheme. Each data array preferably relates to a separate and continuous area of an image.

Abstract: A method and an apparatus to encode a series of quantized coefficients of a transform of a block of image data. The transform is such that 0 is the most likely coefficient amplitude and 1 is the next most likely coefficient amplitude. The method includes forming symbols (called events) from the series of quantized transform coefficients. An event is a run of none or more zero-valued coefficients followed by a run of one of a predefined set of sequences, each sequence in the set being either a single coefficient of amplitude greater than one, or a sequence of 1's and 0's starting with a coefficient of amplitude 1. The method includes forming a codeword for each formed event. Relatively short codewords are formed to represent events that are relatively more likely to occur, and relatively long codewords are formed to represent events that are relatively less likely to occur.