Abstract: A stream of data is accessed from a memory system by an autonomous memory access engine, converted on the fly by the memory access engine, and then presented to a processor for data processing. A portion of a lookup table (LUT) containing converted data elements is preloaded into a lookaside buffer associated with the memory access engine. As the stream of data elements is fetched from the memory system each data element in the stream of data elements is replaced with a respective converted data element obtained from the LUT in the lookaside buffer according to a content of each data element to thereby form a stream of converted data elements. The stream of converted data elements is then propagated from the memory access engine to a data processor.

Abstract: A method and device for coding screen content into a bitstream by selecting a color palette table for a coding unit (CU) of screen content, creating a color index map having indices for the coding unit (CU), and encoding the selected color palette table and the color index map for the CU into a bitstream.

Abstract: An image data processing method is provided. The image data processing method includes the following steps: receiving image data, wherein the image data is in a first pixel format; shuffling the image data according to a relationship between the first pixel format and a second pixel format to generate shuffled data; and compressing the shuffled data by a compression module which is suitable for compressing image data in the second pixel format so as to generate compressed data.

Abstract: A tile of pixels is encoded by variable length encoding at least a first block of pixels into a first sequence of symbols and a second block of pixels into a second sequence of symbols. The symbols of the first and second sequences are co-organized into a combined sequence of symbols in which the symbols of the first sequence are readable in a first reading direction and at least a portion of the symbols in the second sequence are readable in a second, opposite reading direction. The encoding of the tile to form one or more combined sequences significantly reduces the bandwidth requirements when writing the tile to a pixel value buffer. The co-organization of the first and second sequences enables parallel reading and decoding of the first and second sequences from the pixel value buffer, thereby reducing any decoding latency.

Abstract: Some aspects of the disclosure relate to a compression technique that can permit determining dynamically a satisfactory quantization matrix based at least on properties intrinsic to a digital object being compressed and a predetermined compression quality criterion, wherein the quantization matrix is associated with a specific space-domain-to-frequency-domain transforms. In one aspect, the compression technique can permit creation of a compressed digital object that can satisfy a predetermined a compression quality criterion.

Abstract: Based on an m×n halftone matrix and an m×n pixel block of an image, an m×n halftone version of the m×n pixel block may be determined. An n-way interleave may be performed on rows of the m×n halftone version to create an mn×1 halftone segment. The mn×1 halftone segment may be compared to one or more halftone segments in a buffer. Based on the comparison, a literal code word and a representation of the mn×1 halftone segment may be output, and the representation of the mn×1 halftone segment may be written to the buffer. Alternatively, a repeat code word and a repeat value may be output, and at least one representation of the mn×1 halftone segment may be written to the buffer.

Abstract: A scanner device includes an analog front-end component and an image processing component. The analog front-end is configured to receive, from a scan head, analog signals carrying analog image slices and provide compressed digital signals. The analog front-end component has a data compressor configured to compress digital image slices that correspond to the analog image slices digitized, wherein each analog image slice is comprised of a plurality of analog pixel values that represent a slice of the target medium. The image processing component has a data decompressor configured to (i) receive and decompress the compressed digital signals into digital signals, and (ii) generate an image file of a target medium based at least in part on the digital signals.

Abstract: Embodiments herein provide for a pre-processing stage or mechanism for enhancing data compression of an image by splitting or separating the color channels for pixels into planar data sources. Typically, image data is displayed as an interleaved set of channel types for a color space such that each pixel within an image (such as a bitmap) has one component for each color channel. By separating the interleaved bitmap into a planar representation, each plane can be compressed independently and often times achieve higher compression ratios. This is especially true for channels that are expected to stay fairly constant throughout the bitmap most of the time. The utilization of the above embodiment can be further enhanced through manipulation of channel data or through converting the color space from one form to another.

Abstract: A reconfigurable operation apparatus includes a reconfigurable circuit, a storage unit and a control unit. The reconfigurable circuit has a plurality of small circuits and reconfigures a circuit using the small circuit selected from the plurality of small circuits based on recorded circuit information. The storage unit stores first and second circuit information which corresponds to first and second compression circuits, respectively. The control unit reconfigures the reconfigurable circuit into the first or second compression circuit by recording the first or second circuit information in the reconfigurable circuit in accordance with an input data string.

Abstract: After an input image signal (2000) of a smaller resolution is encoded by an encoder (20), an input image signal (1000) of a greater resolution is subjected to motion compensation processing by a motion compensation unit (102) according to motion information (1998), thereby generating a prediction error signal (1001). Simultaneously with this, an enlarged decoded image (2003) obtained by enlarging the decoded image (2002) obtained by an encoder (20) is subjected to motion compensation processing by a motion compensation unit (103) according to the motion information (1998), thereby generating a prediction error signal (2005). By referencing the prediction error signal (2005), the prediction error signal (1001) is subjected to conversion encoding, quantization, and entropy encoding.

Abstract: A color look-up table (CLUT) is compressed in a lossless manner. The CLUT includes nodes that convert values of a first color space to corresponding values of a second color space. The CLUT is received in a serialized node-by-node manner. For each of some of the nodes, the following is performed in the order in which the nodes are received in the serialized node-by-node manner. First, a difference value is determined that represents compression of a value of the node, in accordance with a hierarchical differential encoding approach or in accordance with a cellular interpolative prediction approach. Second, the difference value is stored in lieu of the value of the node being stored, to compress the value of the node in the lossless manner.

Abstract: An approach is provided for implementing locked printing on a printing device with remote unlock. The printing device includes a locked print process that is configured to examine print data received by the printing device and determine whether locked printing is to be used for the print data. Print data designated for locked printing is stored on the printing device. The printing device also includes a Web application configured to generate Web pages that define a Web-based graphical user interface. When processed at a client device, the Web pages allow a user to enter authorization data that is transmitted to the Web application on the printing device. The locked print process verifies the authorization data and if the authorization data is successfully verified, allows the user access to locked print data on the printing device. The approach may also be implemented using a common repository to store print data.

Abstract: Embodiments herein provide for a pre-processing stage or mechanism for enhancing data compression of an image by splitting or separating the color channels for pixels into planar data sources. Typically, image data is displayed as an interleaved set of channel types for a color space such that each pixel within an image (such as a bitmap) has one component for each color channel. By separating the interleaved bitmap into a planar representation, each plane can be compressed independently and often times achieve higher compression ratios. This is especially true for channels that are expected to stay fairly constant throughout the bitmap most of the time. The utilization of the above embodiment can be further enhanced through manipulation of channel data or through converting the color space from one form to another.

Abstract: A system for and method of efficient interoperability assessment based on automated Behavioral Profiling and Emulation of SIP or T.38 Fax-relay Enabled Devices, for example, for profiling and emulating VoIP Phones such as SIP Phones, or T.38 Fax-relay devices such as Internet Aware Fax Terminals. The method includes a Multi-step/Multi-technology Iterative Profiling Stage that allows creating a Behavioral Profile based on the analysis of a plurality of traffic samples. Also, the method presents an efficient process of Device Emulation of an actual device to be used in interoperability assessment, including a Standard State Machine parameterized by a set of characteristics stored in the Behavioral Profile. The Emulation method can be used to duplicate one or more device behaviors exhibited either by different firmware revisions, software upgrades or by different OEM product models.

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 Image Signal Processing unit (ISP) has at least one fixed-size line buffer which is smaller than the width of the image buffer. To handle the image data, the image buffer is divided into regions which are sequentially loaded into the at least one fixed-size line buffer of the ISP for processing. Since functions of the ISP operate with neighboring pixels of the target pixel, margins of the regions need to be transmitted as well. After processing by the ISP, the data is encoded which includes a DCT, Quantization, and VLC. The result is then stored in segments in a buffer storage. VLC also inserts a Restart Marker which is used as a pointer to stitch together all the segments thus producing a new and seamless image.

Abstract: A variable-length encoding apparatus receives image data on a block basis, generates a plurality of syntax elements from the image data, and outputs an encoded stream by performing variable-length encoding of the syntax elements. This apparatus includes a block memory unit group including at least two block memory units which store image data on a block basis, generates at least one syntax element by reading out transformation coefficients from the block memory units, independently variable-length-encodes each of syntax elements and outputs variable-length codewords, includes a variable-length code memory unit group including at least two variable-length code memory units which independently store the variable-length codewords as codeword streams, and generates one encoded stream from the respective codeword streams supplied from the variable-length code memory unit group.

Abstract: Reduction in the blockiness of a simulated film grain block can be achieved either by the use of adaptive downscaling or adaptive deblocking filtering to adjust the intensity of the pixels at the block edge in accordance with at least one film grain block parameter, such as film grain size, intensity and texture. Performing such adaptive downscaling or adaptive deblocking filtering achieves improved performance at lower computational cost by avoiding modification of film grain block pixels in lesser affected areas.

Abstract: A method for compressing a digital image to be printed, the image consisting of pixels. It is determined, for blocks of pixels, whether a block contains a graphical structure that is to be maintained without loss because it is of a type that can be accurately perceived by a human observer. The block is encoded losslessly into a less voluminous format, if such a graphical structure has been found. Otherwise, the block is compressed lossily, if no such graphical structure has been found.

Abstract: Entropy coding and decoding techniques are described, which may be implemented separately or in combination. For example, a video encoder uses two-layer run level coding to reduce bitrate for frequency transform coefficients in a quick and efficient manner, and a video decoder uses corresponding two-layer run level decoding. This two-layer coding/decoding can be generalized to more than two layers of run level coding/decoding. The video encoder and decoder exploit common patterns in run level information to reduce code table size and create opportunities for early termination of decoding. Using zoned Huffman code tables helps limit overall table size while still providing a level of adaptivity in encoding and decoding. Using embedded Huffman code tables allows the encoder and decoder to reuse codes for 8×8, 8×4, 4×8, and 4×4 blocks.

Abstract: The invention describes a process to prevent counterfeiting or alteration of a printed or engraved surface, characterized by the incorporation of a signature of the form of a digital mark into parts or the entire document, and in particular a digital mark technology to hide information in an invisible way through over-printing by using a method called asymmetric amplitude modulation. This method can be applied to any type of printed material such paper, packaging, or any other surface. Visible information can also be printed over the digital mark. As an application example, applied to a paper document the digital mark can be used to guarantee the document authenticity, as it would be destroyed by a copy process.

Abstract: Lossless, near-lossless, and lossy compression and decompression of digital image data, whereby the image data can be compressed and decompressed on-the-fly with no need for external RAM resources for temporary data storage while compressing/decompressing image data. Implementing the algorithm only requires a very limited amount of silicon and yields very high performance in relation to very low power consumption. The described implementation is optimized for raw image data from a sensor with a Bayer filter pattern but can be used on data from image sensors with ay color filter. The compression algorithm contains a line indexing formation which enables very fast subsampling of an already compressed image and the possibility to decompress only parts of an image—this improves performance and reduces the need for temporary RAM storage greatly when zooming and in postprocessing.

Abstract: This invention reduces degradation in quality of a resized image in obtaining the resized image. An image capturing apparatus includes an image sensor which converts an optical image into an electrical signal, an A/D conversion unit which converts an image signal output from the image sensor into digital image data, a color interpolation unit which executes color interpolation of the digital image data, a separation unit which separates the digital image data that has undergone color interpolation by the color interpolation unit into a luminance component and color difference components, an image size conversion unit which converts the image size of the luminance component and color difference components, and a lossless compression unit which losslessly compresses the luminance component and color difference components generated by the image size conversion unit.

Abstract: An Image Signal Processing unit (ISP) has at least one fixed-size line buffer which is smaller than the width of the image buffer. To handle the image data, the image buffer is divided into regions which are sequentially loaded into the at least one fixed-size line buffer of the ISP for processing. Since functions of the ISP operate with neighboring pixels of the target pixel, margins of the regions need to be transmitted as well. After processing by the ISP, the data is encoded which includes a DCT, Quantization, and VLC. The result is then stored in segments in a buffer storage. VLC also inserts a Restart Marker which is used as a pointer to stitch together all the segments thus producing a new and seamless image.

Abstract: An image compressing method includes: separating image data obtained from an image pickup device into each primary color component; obtaining difference data between each piece of image data of color components of colors other than a reference color in the image data separated into each primary color component, and the image data of the color component of the reference color; encoding the difference data to obtain a variable-length code; and encoding the image data of the color component of the reference color to obtain a predicted code.

Abstract: The present invention relates to method and apparatus of converting a series of data words into modulated signals. This method divides a data word, which a sync signal is to be added in front or rear of when it is written in a recording medium, into two or more word segments, generates for each word segment a number of intermediate sequences by combining mutually different digital words with that word segment, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d,k) constrained sequence, checks how many undesired sub-sequences are contained in each (d,k) constrained sequence, and selects one (d,k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d,k) constrained sequences not having the undesired sub-sequence. Applying this method to a modulating device, DSV control can be conducted by much simpler hardware.

Abstract: It is an object of the present invention to provide an encoding device and an encoding method that allow even faster speeds to be achieved by reducing the waiting time during which variable-length encoding is performed. An encoding device performing run-length encoding and variable-length encoding sequentially inputs one block of m×n data, determines whether a value of each unit of input data is 0 (zero), stores the results of the determination to an information register and stores input data to a data buffer, controls the reading of data from the data buffer based on the results of the determination, performs run-length encoding using the data read from the data buffer and the results of the determination, and performs variable-length encoding using as a data pair the data and the number of consecutive data having a value of 0 (zero).

Abstract: An image compression method for compressing groups of pixel data, including the following steps: MSB portions and LSB portions of the pixel data are compressed separately. Further, the LSB portions are grouped according to their associated MSB portions so that similar pixels are compressed together to gain higher a compression ratio. Some LSB portions are truncated to ensure a compression ratio. When performing compression, enhanced variable-length coding is adopted that predicts more accurate dividers by considering weighted combination of adjacent pixels. The quotient of each groups of compression portion is predicted and coded accordingly.

Abstract: An apparatus and a method of changing a bit rate of a compressed image bit stream by changing a codeword so as to easily change the bit rate and reduce a changing loss. The apparatus for changing a bit rate, in which an input bit stream generated by an image compression encoding method is changed into an output bit stream having a desired bit rate, includes a changing codeword determiner which selects codewords to replace the codewords of the input bit stream, and a codeword changer which changes the codewords of the input bit stream into the codewords selected by the changing codeword determiner. The method and the apparatus can be applied to image services provided through the Internet and receiving apparatuses supporting the Personal Video Recorder (PVR) function. Particularly, the method of changing the bit rate of a compressed image bit stream changes the codewords of input transform coefficients so as to easily change the bit rate and reduce the changing loss.

Abstract: There is disclosed in embodiments methods relating to the compression of printing hints. The method in embodiments generates a first set of image pixels having corresponding printing hints. The printing hints are then adjusted to produce a second set of image pixels processed in such a way that an end printed result is visually equivalent to a printed result using the first set of image pixels thereby reducing the entropy in the printing hints. The method improves the compression ratio of an image using printing hints by adjusting the printing hints of pixels that are zero or fully saturated. The printing hints are adjusted in such a way to reduce the complexity of the printing hints.

Abstract: A lossless image encoding/decoding method and apparatus. The lossless color image encoding apparatus includes a motion prediction image generator estimating a motion between a previous image and a current image and outputting a corresponding prediction image, a residue generator generating a temporal residue corresponding to a difference between a prediction image generated by the motion prediction image generator and the corresponding block of the current image with respect to different components of the color image, a prediction residue generator generating prediction residues by defining a linear-transformed value of one residue among the different components of the color image output from the residue generator as a predictor and using differences between each of the residues of the other components and the predictor, and an entropy encoder receiving the residue forming the predictor from the residue generator and the prediction residues from the prediction residue generator and generating a bitstream.

Abstract: To provide an image coding apparatus that can generate a code that can be decoded by a general decoding apparatus while attaining a high coding speed. As a result of processing in a plurality of prediction units 21, a control unit 11 generates a predicted pixel value for a pixel of interest based on a pixel value of a predicting pixel located at a distance from the pixel of interest, the distance being predetermined for each pixel value prediction unit 21, counts, as a run-length for each pixel value prediction unit 21, the number of times that the pixel value of the pixel of interest successively correspond with the predicted pixel value, selects any of pixel value prediction units related to a run-length of one pixel or more, and outputs a code by referring to a predetermined code table with respect to a distance between the pixel of interest and the predicting pixel for the selected pixel value prediction unit 21 and the run-length thereof.

Abstract: A plurality of patterns such as solid patterns, edge patterns, half-tone patterns, and verbatim data are losslessly represented in a compressed raster data stream. A pattern selection module selects among the various patterns to provide the best combination of lossless representations according to particular criteria such as storage compactness. A packet formatting module packs multiple pattern identifiers and lossless representations into a packet which may be transmitted compactly. Upon receipt, a packet deformatting module unpacks the pattern identifiers and lossless representations from the packet. After deformatting, a pattern decoding module uses the pattern identifier to activate appropriate pattern generation modules. Each pattern generation module regenerates data according to an indicated pattern to recreate the original raster data.

Abstract: An image processing device, an image processing program and an image processing method for forming a composite image by superimposing an overlay image on a base image. Fixed length compressed image of the base image fixed length compressed data of the overlay image are formed by dividing data of the base image and data of the overlay image respectively into a plurality of blocks and by encoding a statistical parameter of each block, including a gray level representing the block, and quantization levels of respective pixels in the block. Then, while the fixed length compressed data is being checked in a block-by-block manner, the fixed length compressed data of the base image is taken in if the gray level of the block of the overlay image is 0, and the fixed length compressed data of the overlay image is taken in if the gray level of the block of the overlay image is not 0.

Abstract: For the entropy coding of image data after subjected to orthogonal transforation and quantization, a plurality of entropy coding units are provided in parallel. The plurality of entropy coding units can be operated efficiently and the entropy coding can be executed at high speed.

Abstract: Without repeating compression/decompression operations, an editing process such as rotation can be executed using first compression data, and second compression data, whose compression ratio is increased, can be stored in a hard disk drive.

Abstract: Two-dimensional blocks of line-work image data are subjected to: fractal reordering; run length encoding of the pixel values of the fractal re-ordered data, index encoding of the run length encoded pixel values; and entropy encoding of the index encoded pixel values and run lengths. This lossless, but in case of applying a quantisation step, lossy image data compression and decompression method is particularly suitable for handling image data in a printer environment, and more particularly for handling image data comprising line work data or both raster images and line work data.

Abstract: Traps are produced at color boundaries in a print page that is present in the form of run-length encoded image data, by way of distance mapping. Distances of the run lengths to an adjacent color are determined without decoding the run lengths into a pixel matrix, and the traps are produced on the basis of the distances thus determined. For this purpose, distance vectors are determined for the starting point and for the end point of a run length. The distance vectors are in each case recalculated from the comparison with the distance vectors of adjacent run lengths. The new values of the distance vectors replace the previous values of the distance vectors if the magnitudes of the distances of the new values are less than the magnitudes of the distances of the previous values.

Abstract: A method, apparatus, and information bearing medium for merging display items in encoded form involve providing display items to be merged in an encoded format, such as a run length encoded format (e.g., modified enhanced run length encoded format). The display items are examined on the basis of item priority. A target item having a target area is defined. The display items in the target area are merged according to item priority to produce the target item. The target item is representative of the merged display items. The encoded data associated with the display items to be merged includes control data and color data. In one embodiment, tokens are produced using the encoded data associated with the display items to be merged. The display items are merged using the tokens. The tokens represent counts of repeated data or pointers to pass-thru data associated with the display items to be merged.

Abstract: Edge delta runlength (EDRL) compression algorithms may be employed to compress bi-level black print data, such as data representing text. A printer capable of rapidly decoding the compressed EDRL data includes a decoding circuit to produce delta signals. An edge calculation circuit in turn operates on the delta signals to produce runlength data which is subsequently transformed into image line data by a runlength decoder circuit.

Abstract: In order to decrease a required memory capacity of a line memory and to efficiently compress an image by coding, even when character information is contained in a high-resolution image, each time the block of an image that is equally divided into M (M: an arbitrary integer greater than 1) blocks in the horizontal direction is updated, difference data between color code data at corresponding pixel positions in the horizontal line and the adjacent immediately-preceding horizontal line with respect to each horizontal line within the block is detected by a line memory and an exclusive-OR circuit.

Abstract: A printer driver software product is provided for execution by a computer to produce compressed page data corresponding to a page layout. The driver includes instructions to generate continuous-tone data and bi-level text and black graphics data from print data corresponding to the page layout. Data compression instructions are also included in the printer driver. Upon execution the data compression instructions cause the computer to compress the set of continuous-tone data and the set of bi-level text and black graphics data to produce compressed page data corresponding to the page layout. The compressed data is then transmitted to a printer in communication with the computer. A printer driver software product according to the invention is particularly useful where a printer is coupled to a computer by means of a relatively limited bandwidth connection.

Abstract: A method for serving an image from a server to a client, e.g., a computer having a browser or other graphics viewing engine. The user of the client first specifies a set of one or more bitmap characteristics for an image transfer, with at least one of the bitmap characteristics including a number of bits per pixel. Preferably, this specification is accomplished using an applet or other piece of code that is downloaded to the client from the server. Later, when the server receives a client request that includes data identifying a specified bitmap characteristic, a server processing routine (e.g., a servlet) generates a version of the image that conforms to the specified bitmap characteristic. This version is then delivered back to the client in response to the original request. In this way, the user of the client machine can control the particular characteristics of the image files that are delivered to his or her machine.

Abstract: A plurality of patterns such as half-tone patterns, solid patterns, edge patterns, and verbatim data are losslessly represented in a compressed raster data stream. A pattern selection module selects among the various patterns to provide the best combination of lossless representations according to particular criteria such as storage compactness. Half-tone patterns are compressed by exploiting the characteristics of the half-tone threshold screen used to generate the half-tone image. A half-tone pattern codebook is produced by half-tone screening a calibration image. A packet formatting module packs multiple pattern identifiers and lossless representations into a packet which may be transmitted compactly. Upon receipt, a packet deformatting module unpacks the pattern identifiers and lossless representations from the packet. After deformatting, a pattern decoding module uses the pattern identifier to activate appropriate pattern generation modules.

Abstract: A system and associated method automatically and very rapidly determine the dominant periodicity in sequential binary data. The method incorporates a fast binary autocorrelation function used to discover the dominant periodicity in a sequential binary signal, and exploits this information in a periodicity exploiting application, such as using any one or more of a pixel periodicity or an edge periodicity based compression method in order to compress periodic halftoned bitonal images. The method implements four processes: The first process describes setting up the data in a transition-based representation to facilitate an algorithm to quickly find an autocorrelation distribution derived from a sequential binary signal. The second process describes a fast dominant periodicity search algorithm. The third process describes an algorithm that estimates the dominant window for estimating the dominant periodicity within one line of two-dimensional sequential binary signal.

Abstract: A system and method for accepting raster data from a Postscript or equivalent image data generator, identifying portions of the raster image which contain continuous tone data and linework data, dividing those portions into separate tiles and compressing the data within each tile by a compression method optimized for the type of image data within the tile. The compression algorithms are based upon conventional JPEG or LZW techniques, but enhanced to more efficiently process image data sets with large amounts of blank data.

Abstract: An apparatus and method for performing bitplane coding with reordering, that may be used in a Fine Granularity Scalability (FGS) system. The apparatus and method reorder coefficients each time after a bitplane is coded. By reordering, the apparatus and method separate the coefficients into two groups. When coding a bitplane, bits in the first group are copied into the bitstream, while the bits in the second group are subject to common run-length, VLC, or arithmetic coding. The apparatus and method may also be used with or in a conventional SNR, temporal and/or spatially scalable architectures, for example, as utilized within an MPEG-4 framework.

Abstract: A method for losslessly transmitting data is provided. The data is separated into two or more portions and the second portion is subtracted from the first portion to find a difference. The first portion and the difference are transmitted, and then the second portion is reconstructed by adding the difference to the first portion. The data may comprise two or more images, with each image being a temporally displaced version of the preceding image. Each image may be divided into multiple areas, where the areas on each image correspond to the areas on the other images. A difference may be obtained by subtracting each area of an image from the corresponding area of the preceding image. The first image may then be transferred as a reference image along with the differences, and each image may be reconstructed by adding each difference to the corresponding area of the previous image.

Abstract: An image processing device which processes a portion of the decompression process including a lot of comparatively complex operations like an inverse discrete cosine transform by software with using a high-performance, general-purpose processor capable of parallel processing, and the other portion of the decompression process which is compara- tively simple but requires frequent access to a memory, e.g., when other frame data is to be read out for processing of encoded interframe predictive image data, or is compara- tively simple but substantially hard to process in parallel, e.g., when variable length coded pixel values are to be decoded, by hardware with the use of a specialized periph- eral circuit.

Abstract: The present invention relates to an image processing technique, and in particular to a method for restoring a compressed image by using a hybrid motion compensation discrete cosine transform (hybrid MC/DCT) mechanism, including: a step of defining a smoothing functional having a smoothing degree of an image and reliability for an original image by pixels having an identical property in image block units; and a step of computing a restored image by performing a gradient operation on the smoothing functional in regard to the original image, thereby preventing the blocking artifacts and the ringing effects in regard to the pixels having an identical property in image blocks. In one embodiment, the method includes obtaining a pixel value in a current block and at least one adjacent pixel value according to a smoothing direction, and obtaining a smoothing value of the current image based on the obtained pixel value in the current block and the adjacent pixel value according to the smoothing direction.