Abstract: A method and system of reducing the computation load of an MPEG decoder by changing the encoding algorithms in a video-processing system are provided. During an encoding mode, a stream of data blocks is received and at least one motion vector and one motion compensation prediction value for each macro-block are generated. The prediction value is transformed into a set of DCT coefficients. Prior to the quantizing step, the set of DCT coefficients are modified according to predetermined criteria. To this end, the total energy level of the DCT coefficients excluding the lowest 2×2 DCT coefficients is computed, and last column and last row of the DCT coefficients is discarded alternatively until the total energy level of the DCT coefficients reaches a predetermined energy level. Therafter, the discarded column or row is assigned to a predetermined value.

Abstract: In a MPEG or other video system, editing is performed using “independently coded regions” (ICRs) embedded into an input video signal. These regions facilitate quick editing and formatting of a compressed output signal; for example, logo insertion, color correction, blue-matting and various types of image sequence mixing and manipulation may be performed by decoding and processing individual regions rather than entire frames. Preferably, each independently coded region is recognizable directly from a compressed video bitstream and is retrieved by decoding select image slices. Once editing or processing is complete, new compressed bitstream data is inserted into the place of the original compressed data. Each independently coded region features the attribute that motion vector and residual data for compressed frames are limited to point only to corresponding regions of anchor frames.

Abstract: A method for robust time domain block decoding is disclosed. In one embodiment, the method includes receiving a block of transform domain coefficients, detecting errors in one or more transform domain coefficients, decoding pixel values from the transform domain coefficients, determining a first estimate for each erroneous pixel value, and updating the decoded pixel values.

Abstract: An input digital signal of a first format (DV video signal) is restored to a variable-length code by having its framing cancelled by a de-framing section 11, then decoded by a variable-length decoding (VLD) section 12, inversely quantized by an inverse quantizing (IQ) section 13, and inversely weighted by an inverse weighting (IW) section 14. Then required resolution conversion in the orthogonal transform domain (frequency domain) is carried out on the inversely weighted video signal by a resolution converting section 16. After that, the video signal having the resolution converted is weighted by a weighting (W) section 18, then quantized by a quantizing (Q) section 19, coded by a variable-length coding by a variable-length coding (VLC) section 20, and outputted as a digital signal of a second format (MPEG video signal).

Abstract: A method and apparatus for coding and decoding information is described. In one embodiment, the apparatus comprises a memory and decoding hardware. The memory stores run counts and/or skip counts and the decoding hardware decodes a run count and/or a skip count obtained from the memory during decoding.

Abstract: An apparatus for partitioning moving picture data comprises a first quantizing unit for first-quantizing a received video signal and outputting a first-quantized signal; and a second quantizing unit for second-quantizing the first-quantized signal and partitioning the first-quantized signal into a preceding part and a succeeding part.

Abstract: Header information capture section extracts information such as the numbers of dots in horizontal and vertical directions, respectively, of the picture, a frame rate and so on from a sequence header included in an MPEG video stream. Total processing amount estimation/reproduction scheme determination section receives a channel priority determined for each display mode and an output of header information capture section to estimate a total processing amount and determine a reproduction scheme for each channel. MPEG decoder receives code inputs of channels 1 to 4 in a time-dividing manner through header information capture section to perform decoding of picture codes of each channel according to a determination signal outputted from total processing amount estimation/reproduction scheme determination section.

Abstract: A method is provided for transcoding between video signals in two standards, DV and MPEG-2, each standard including discrete cosine transform (DCT) compressed signals. The each of the signals have macroblocks containing a plurality of DCT blocks. The DCT blocks are quantized according to respective quantization methods defined by the standards. The coefficients in each block are zigzag scanned, run-length coded and variable-length coded. The process variable-length decodes the coefficients and translates the quantized coefficients in the DV standard into quantized coefficients in the MPEG standard without fully dequantizing at least some of the DV coefficients and without performing an inverse DCT operation on any of the DCT coefficients. DV blocks that are encoded in a 248 format are translated into an 88 format before they are converted to MPEG-2 blocks. A method for transcoding from MPEG-2 to DV is also described.

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: Original-quality MPEG coded video is processed to produce reduced-quality MPEG coded video at a reduced bit rate. The processing is based on a scale factor between average frame size of the original-quality MPEG coded video and a desired average frame size of the reduced-quality MPEG coded video. For each Discrete Cosine Transform (DCT) block of each frame, the processing calculates a size of the block of the reduced frame by scaling the original block size by the scale factor, and removes a sufficient number of bits from the original block to obtain substantially the calculated size. In addition, the processing accumulates excess bits when the block size reduction eliminates more bits from a block than are necessary for the desired reduction of the size of the block, and any excess bits are used for processing a number of following blocks.

Abstract: A video reception device, such as personal computer, generates high quality video from video data received from a video capture device over a low data rate communication interface such as a USB interface. The video data is received by the reception device in two passes. The first pass provides a low frequency portion of coefficients and the second pass provides a high frequency portion of coefficients. The coefficients representing the video are generated by performing a Discrete Cosine Transform (DCT) on blocks of pixels and compressing a portion of the coefficients. In one embodiment, the video reception device matches a frame received during the first pass with a frame received during the second pass and signals the video capture device to switch from compressing the low frequency portion of coefficients to compressing the high frequency portion.

Abstract: A method and device for reducing a compressed image to a target size by reducing the quality of the image by a quality scaling factor. Image statistics inherent to the image are used to compute the size reduction as a function of the quality scaling factor. Using the relationship between the quality and the size of the image, an estimated quality scaling factor is obtained based on the target size in an iterative process until the size reduction corresponding to the estimated quality scaling factor is substantially equal to the target reduction.

Abstract: Adjacent blocks are identified in an image. Coding parameters for the adjacent blocks are identified. Deblock filtering between the identified adjacent blocks is skipped if the coding parameters for the identified adjacent blocks are similar and not skipped if the coding parameters for the identified adjacent blocks are substantially different.

Abstract: An encoder including a DCT transformator for receiving an image or video frame and performing DCT transformation upon a pixel block in a macroblock of the frame, thereby providing a matrix of DCT coefficients, a zig-zag matrix-to-vector converter for receiving the matrix of DCT coefficients from the DCT transformator and creating a one-dimensional vector of DCT coefficients, an analyzer for receiving the one-dimensional vector of DCT coefficients and classifying the macroblock according to a level of detail and edginess, a rate controller for receiving the classification information from the analyzer and selecting DCT filtering parameters, a DCT filter for receiving the DCT filtering parameters selection from the rate controller and implementing the DCT filtering parameters upon the frame, thereby providing a filtered DCT coefficient vector, a quantizer for quantizing the filtered DCT coefficient vector, and a compressor for compressing the quantized results.

Abstract: The present invention relates to a device for processing blocks of coded data included in a sequence of coded digital images (ES) according to a block-based coding technique, said device comprising a post-processing circuit DFD (33). Such a device effectively corrects the blocking artifacts while minimizing the bandwidth used, the decoder directly transmitting decoded data blocks (B) to the post-processing circuit. In addition, such a device introduces no or little drift during the decoding since the decoder continues to use reference images (RB) during a motion compensation step. This is because the reference images are no longer the decoded images but the completely processed images as the post-processing circuit is situated in the decoding loop.

Abstract: The invention relates to a method of video processing applied to N encoded video input signals, for decoding and reducing by a factor N the format of said encoded video input signals, and for generating a set of decoded video signals in the pixel domain, each encoded video input signal comprising DCT blocs. The method according to the invention is characterized in that it comprises a first and second inverse DCT step, each inverse DCT step being applied simultaneously on a plurality of DCT blocs of reduced size extracted from said N encoded video input signals. Thus are generated N output blocs of reduced size defining one of said decoded video signal of reduced format by a factor N. This invention can advantageously be used for the composition of mosaic video signals from a set of encoded signals.

Abstract: A transformation unit 102 transforms an entered image to multi-resolution space. A quantizer 105 performs vector quantization on a local pattern of an image of a multi-resolution representation. A perspective-order calculating unit 107 extracts a plurality of code words, positions corresponding thereto and/or angle of rotation and/or scale, and the perspective-order relationship of a plurality of these representative vectors, from the quantized image. An algebraic encoder 108 encodes the input image based upon the extracted information. As a result, there are provided an image processing apparatus and method for asymmetric encoding without motion in three dimensions and extraction of a three-dimensional structure. Further, a transformation unit 1103 transforms an entered image to vector field, and a singularity detector 1104 detects a singularity in the transformed image.

Abstract: The horizontal and vertical offset for the M×N DCT block boundaries are determined for a decompressed image originally produced by a DCT-based compression system, regardless of the amount of compression and/or cropping that had been applied to the image. The method includes the steps of: a) computing one or more selected DCT coefficients from nonoverlapping, contiguous M×N blocks of the decompressed image, beginning at a selected offset; b) computing a coefficient histogram from a set of values for each selected DCT coefficient obtained from the blocks of the decompressed image; c) computing a dispersion metric from each coefficient histogram; d) repeating steps (a) through (c) for a plurality of offsets within an M×N block; e) comparing the dispersion metrics corresponding to the plurality of offsets to determine the minimum dispersion coefficient histogram; and f) selecting the offset that corresponds to the minimum dispersion coefficient histogram as the offset for the DCT block boundaries.

Abstract: Herein disclosed a bit stream separating apparatus for inputting and transcoding an original MPEG-2 bit stream, and separating the transcoded MPEG-2 bit stream to generate a transcoded MPEG-2 bit stream and a differential bit stream, which is a differential bit stream between the original MPEG-2 bit stream and the transcoded MPEG-2 bit stream, and a bit stream merging apparatus for inputting and merging the transcoded MPEG-2 bit stream and the differential bit stream to reconstruct the original MPEG-2 bit stream. The bit stream separating apparatus makes it possible for the bit stream merging apparatus to reconstruct the original, high quality, MPEG-2 bit stream from the transcoded MPEG-2 bit stream already received and the differential bit stream, thereby eliminating the effort and time to send the original MPEG-2 bit stream again.

Abstract: A MPEG-2 decoder receives an MPEG-2 video stream containing discrete cosine transform (DCT) blocks and generates linear contrast enhanced DCT blocks applied to an inverse DCT processor contained therein. Preferably, the MPEG-2 decoder includes a linear contrast enhancement processor receiving the DCT blocks and generating the linear contrast enhanced DCT blocks, and the inverse DCT processor coupled to the linear contrast enhancement processor. Additionally, the MPEG-2 decoder can include a microprocessor which controls the linear contrast enhancement processor and the inverse DCT processor. A method and a memory containing computer readable instructions permitting the microprocessor to control the MPEG-2 decoder are also described.

Abstract: The invention concerns a method for synchronising a video image (IM) spatial position to find the position of an initial digital coding grid (GI), by said image (IM) coding blocks, characterised in that it consists in the following steps: a) moving along the direction of the image (IM) lines and/or along the direction perpendicular to the image (IM) lines, an analysis grid (GA) consisting of coding blocks and corresponding to at least part of the image (IM); b) determining for each position of the analysis grid (GA), the transformed coefficients Fu,v of each block of the analysis grid (GA), using a discrete cosine transform (TCD); and computing for each analysis grid (GA) position, an activity parameter (AM, ES) representing the image activity; c) determining the analysis grid (GA) position for which said activity parameter (AM, ES) has a minimal value.

Abstract: A method is adapted for compressing an image data block, and includes the steps of: (a) subjecting the image data block to discrete cosine transformation so as to generate discrete cosine transform data; (b) quantizing the discrete cosine transform data in accordance with a quantizer matrix that consists of an array of quantizing coefficients so as to generate quantized data; (c) encoding the quantized data using an entropy coding algorithm so as to generate an encoded bitstream; and (d) when the length of the encoded bitstream does not fall within a predetermined range, adjusting the quantizing coefficients in the quantizer matrix and repeating steps (b) and (c) until the length of the encoded bitstream falls within the predetermined range.

Abstract: An apparatus to determine a transform of a block of encoded data the block of encoded data comprising a plurality of data elements. An input register is configured to receive a predetermined quantity of data elements. At least one butterfly processor is coupled to the input register and is configured to perform at least one mathematical operation on selected pairs of data elements to produce an output of processed data elements. At least one intermediate register is coupled to the butterfly processor and configured to temporarily store the processed data. A feedback loop is coupled to the intermediate register and the butterfly processor, and where if enabled, is configured to transfer a first portion of processed data elements to the appropriate butterfly processor to perform additional mathematical operations and where if disabled, is configured to transfer a second portion of processed data elements to at least one holding register.

Abstract: A system and methods are shown for improved processing of motion compensated video. A software driver handles image data related to motion compensated video. The image data includes IDCT coefficients and motion compensation vector data. A unique identifier is attached to the image data, preserving the relationship between the IDCT coefficients and motion compensated vector data related to an image block. The software driver sends the IDCT coefficients to an IDCT component. The IDCT coefficients are processed and an interrupt is sent to the software driver including the unique identifier of the processed IDCT coefficients. The software driver sends the motion compensation vector data related to the unique identifier in the interrupt. A 3D pipe receives the motion compensation vector data and reads the corresponding processed IDCT data.

Abstract: An apparatus to determine a transform of a block of encoded data the block of encoded data comprising a plurality of data elements. An input register is configured to receive a predetermined quantity of data elements. At least one butterfly processor is coupled to the input register and is configured to perform at least one mathematical operation on selected pairs of data elements to produce an output of processed data elements. At least one intermediate register is coupled to the butterfly processor and configured to temporarily store the processed data. A feedback loop is coupled to the intermediate register and the butterfly processor, and where if enabled, is configured to transfer a first portion of processed data elements to the appropriate butterfly processor to perform additional mathematical operations and where if disabled, is configured to transfer a second portion of processed data elements to at least one holding register.

Abstract: In a method and a device for calculation of the Discrete Cosine Transform (DCT) only the DCT coefficients representing the first half and the second half of an original sequence are required for obtaining the DCT for the entire original sequence. The device and the method are therefore very useful when calculations of DCTs of a certain length is supported by hardware and/or software, and when DCTs of other sizes are desired. Areas of application are for example still image and video transcoding, as well as scalable image and/or video coding and decoding.

Abstract: The present invention relates to a method for eliminating a blocking effect in a compressed video signal signal. The method of the invention includes: the encoding step of eliminating a blocking effect by compensating the motion of a signal compressed in block unit to be transmitted; the decoding step of restoring the motion compensated video signal to the original video signal by reducing the prediction residual between the motion compensated video signal and the original video signal and the blocking effect; and the post-filtering step of performing post-filtering in a blocking elimination filter in order to eliminate a blocking effect and ring effect remained in the compensated signal. The equation for obtaining the original pixel is made simple by eliminating the remaining blocking effect and ring effect using a loop/post filter.

Abstract: In a signal processing apparatus having a plurality of signal processing circuits where predetermined data is to be output sequentially through the plurality of signal processing circuits, when signal processing is performed at each signal processing circuit, timing necessary for respective signal processing is added to the data to be transmitted, as a header information, so that a complicated construction, such that a circuit for obtaining timing necessary for signal processing is added at each signal processing circuit, can be avoided, and the data can be securely processed and delivered at each signal processing circuit.

Abstract: A method of processing video frame data includes the steps of: receiving a video frame; partially decoding the video frame; fully decoding the video frame to produce macroblocks; determining video data parameters from the partially decoded video frame or both the partially and fully decoded video frame; and encoding the macroblocks based on the determined video data parameters to provide a compressed video frame for subsequent display.

Abstract: A method encodes a video by first measuring a variance of pixel intensities in a current frame. A number of bits to encode the current frame is assigned according to rate and buffer fullness constraints. A multiplier value is determined directly as a function of only the variance and the number of bits assigned to the current frame. Motion vectors between a reference frame and the current frame are estimated, and a sum of absolute difference (SAD) is based on a motion compensated residual between the reference frame and the current frame. An encoding mode is determined for each macro block in the current frame based on the sum of absolute difference, the motion vectors and the multiplier value. Then, the motion compensated residual is encoded based on the encoding mode, multiplier value and the number of allocated bits.

Abstract: Presented is a method for decoding-decompressing a compressed-encoded digital data sequence relating to at least one initial digital image. The method includes receiving the digital data sequence having compressed-encoded data groups separated from one another by at least one restart marker and each one including a respective set of encoded data structures. The method calculates a representative value of the number of encoded data structures being between a first restart marker and a subsequent second restart marker signalling, respectively, the start of a first data group to be decoded and the start of a second data group. The method then extracts from the first data group the encoded data structures, and detects the presence of at least one error, if the number of the encoded data structures extracted is different from the calculated value.

Abstract: There is provided a video communication system, which is capable of preventing damage or loss of video data. The video communication system includes: a video encoder for performing a data hiding to an error information provided from the video decoder, transmitting a processed error information to the video decoder, and performing an error concealment with reference to the error information; and the video decoder for extracting an information on an error frame, providing the extracted frame information to the video encoder, extracting the hidden data provided from the video encoder, and performing an error concealment with reference to the extracted hidden data.

Abstract: The invention is related to methods and apparatus that provide selective filtering of discrete cosine transform (DCT) coefficients. Advantageously, filtering of the DCT coefficients is efficiently performed in the frequency domain, rather than the processing intensive pixel domain (time domain). The DCT filtering is performed “in-loop ” to the DCT encoding and not in a preprocessing approach that is independent to encoding loop. The DCT filtering advantageously reduces the number of bits used to encode a picture, which can preserve compliance with occupancy levels for buffer models while improving picture quality over a conventional technique to preserve bits, such as an increase in the value of the quantization parameter QP.

Abstract: A method for handling video bitstream errors in a multimedia gateway device wherein a gateway device detects errors in the incoming video bitstream and sends a signal to the originating device to refresh the bitstream without need of error detection from an end terminating device. When the terminating device signals for the video bitstream to be refreshed, the gateway locally generates and transmits an appropriate refresh frame. The invention allows the gateway to handle errors for devices such as streaming and message servers that have no built-in error handling.

Abstract: A compressed data buffer 21 maintains an image data loaded from a storage device 1, and a decoding section 22 conducts variable length decoding, inverse quantization and inverse discrete cosine transform, and a pixel data shifting section 23 shifts each value of pixel data to right by 1 bit, and a motion compensating section 24 applies motion compensation processing to the data shifted to right by 1 bit, and the frame data buffer 25 stores an image data to be displayed, and a reference data calculating section 24a of the motion compensating section 24 obtains a reference data from a reference buffer based on a motion vector, and a reference data adding section 24b adds the reference data to a data to which decoding processing has been applied, and a reference data storing section 24c leaves in the reference buffer the data to which the motion compensation processing has been applied.

Abstract: A method for transcoding an MPEG-2 video stream to a new bitrate using the motion vectors from the original stream. A desired bitrate is chosen and the macroblocks of the target frames are requantized accordingly in the transcoder. In order to adjust the motion compensation in the target frames, the difference between the original and target reference frames is added on a pixel-by-pixel basis to the target frame's prediction error, or correction matrix. An ideal quantization value is determined using a perceptive algorithm that reduces image quality in high-activity areas where the human visual system does not perceive quality reduction and enhances image quality in areas where noise is noticeable. The new correction matrix is transformed to a frequency domain by a DCT. A coefficient threshold algorithm then identifies those coefficients that would be set to zero using the ideal quantization value and sets them to zero.

Abstract: An image processing apparatus which performs color transformation and compression/decompression simultaneously on image data so that the number of blocks to be transformed with the color transformation can be reduced and the processing speed can be improved without spoiling the apparent image quality.

Abstract: A de-noising algorithm that obtains an estimate of a noise-free portion of a noise-containing digital signal by applying a set of M linear transforms to the noise-containing digital signal, determining M initial de-noised estimates of each digital element of the digital signal, deriving a combination of weight factors for the M initial de-noised estimates of each digital element by formulating the combination as a linear estimation problem and solving it for the individual weight factors, and formulating a final de-noised estimate of each digital element based on the corresponding M initial de-noised estimates and the combination of weight factors. The combination of weight factors is an optimal combination that is derived such that a conditional mean squared error with respect to the initial de-noised estimates is minimized. The optimal determination is further determined based on a scaling factor that removes explicit dependence to noise variance and on one of several matrices.

Abstract: This method and apparatus described herein imposes masking factors to the determined quantization step sizes of macroblocks of a video sequence such that encoding efficiency is increased. A conditional masking method can be used to take advantage of the fact that P-pictures are more important than B-pictures in terms of motion and scene updates as coding noise in such updates are likely propagated by P-pictures. The masking can be applied conditionally to motion/scene update regions of a picture such that coding noise is reduced and therefore bits are saved from less propagation of this noise. Before encoding each macroblock of a picture from an input video sequence, a video encoder with conditional masking determines if the macroblock type belongs to a significant motion or scene update region. A conditional masking factor is then determined for the macroblock based on the determined macroblock type and the picture coding type.

Abstract: A circuit generally comprising a multiport memory, a direct memory access engine and a programmable gate array is disclosed. The direct memory access engine may be configured to transfer a first program to the multiport memory. The programmable gate array may be configured to (i) load the first program directly from the multiported memory to program a codec function and (ii) generate a video output signal by performing the codec function on a video input signal using video data exchanged with the multiport memory.

Abstract: A method segments a video into objects, without user assistance. An MPEG compressed video is converted to a structure called a pseudo spatial/temporal data using DCT coefficients and motion vectors. The compressed video is first parsed and the pseudo spatial/temporal data are formed. Seeds macro-blocks are identified using, e.g., the DCT coefficients and changes in the motion vector of macro-blocks.

Abstract: There is provided a moving picture coding method, which is capable of effectively processing error concealment through data hiding. The moving picture coding method includes the steps of: extracting a picture header information of an inputted image at an encoder; transmitting the extracted picture header information through data hiding; and performing an error concealment using the transmitted picture header information at a decoder.

Abstract: In accordance with the present invention, a method of transmitting video packets to enhance error concealment and error resilience is described. The method comprises serially encoding macro blocks of encoded video data into packets having roughly uniform length. Macroblocks are serially encoded and added to the video packet until the length of the video packet exceeds a threshold length. The final macroblock is then determined. In some embodiments, the final macroblock is the next macroblock after the threshold length has been exceeded. In some embodiments, the final macroblock is the macroblock that does not exceed the length.

Abstract: An improved motion image encoding method is based on a discrete cosine transform (DCT)-based motion image encoding method that uses a plurality of modified quantization weight matrices, the method including selecting one of the plurality of modified quantization weight matrices based on noise information from input image data, performing DCT on the input image data, and performing quantization on the DCT input image data using the selected modified quanitzation weight matrix.

Abstract: There is provided a moving picture coding method, which hides data in multimedia images. The moving picture coding method includes the steps of: extracting a motion vector of an inputted image through a motion estimation and a motion compensation, and performing a DCT (discrete cosine transform) to a difference image of the inputted image to set an initial quantization parameter; performing a data hiding to the set quantization parameter, and changing the quantization parameter to recognize whether or not the data hiding is performed; performing a quantization using the changed quantization parameter; and performing a data hiding by changing a level value of each block by block unit, to which a DCT is performed.

Abstract: There is provided a moving picture coding method, which is capable of effectively processing error concealment through data hiding. The moving picture coding method includes the steps of: extracting an information on region of interest (ROI) of an inputted image at an encoder; transmitting the extracted information on the ROI through data hiding; and performing an error concealment using the information on the ROI at a decoder.

Abstract: Adaptive compensation for requantization. A reference picture is decoded. Another copy of the reference picture is then requantized and then decoded. Next, an error picture is calculated and stored. The error picture represents the difference between the reference picture as decoded without requantization and the reference picture as decoded with requantization. The error picture and the requantized reference picture are used to generate a predictive picture that at least partially compensates for generational error introduced by requantization. This compensation for error may be adaptively performed based on system conditions.

Abstract: Decimating MPEG or other video data by subsampling the output of an inverse discrete cosine transform (IDCT) module. The decimation process is useful for reducing the volume of data that must be processed to display images on a display device, particularly when the volume of video data received at the decoder is greater than the amount needed to take advantage of the resolution of the display device. For example, high definition television data can be decimated for display on a standard television display device or in a picture-in-picture window, thereby reducing the amount of processing resources needed at the decoder and reducing the size of the frame buffers. Subsampling the output of the IDCT module reduces the volume of data and, for relatively static or constant pans, there is not a significant compounded loss of image quality as successive frames are decoded.

Abstract: A motion picture decoding apparatus according to the invention includes: a coefficient reducing circuit for removing orthogonal transform coefficients for high horizontal frequencies from a certain sized block of orthogonal transform coefficients obtained from an input signal, thereby reducing the number of transform coefficients to half; an inverse orthogonal transformation circuit for performing an inverse orthogonal transform operation by using the transform coefficients reduced by the coefficient reducing circuit, thereby obtaining, on a block-by-block basis, reconstructed image data or time-axis prediction error data horizontally compressed to ½; an adder for generating reconstructed image data horizontally compressed to ½, based on the time-axis prediction error data provided by the inverse orthogonal transformation circuit and on predetermined reference image data; and one or more than one reference image memories for storing reconstructed image data which is included in the reconstructed

Abstract: A method and apparatus for the selective peaking of portions of a video signal is provided. The video signals, such as those transmitted in compressed form, in accordance with MPEG Standards, can be presented as blocks of data encoded using Discrete Cosine Transforms (DCT). The Discrete Cosine Transform coefficients corresponding to the chrominance values of the signal can be obtained and analyzed. The analysis and corresponding amounts of enhancement (peaking) can be performed on a block-by-block, I-frame by I-frame, basis to selectively peak portions of a video signal. If the DCT coefficients for a portion of the signal exceed or fall within a pre-selected value or range, that portion of the signal can be subjected to peaking. For example, if the high frequency horizontal DCT coefficients exceed (or fall within) a pre-set threshold value or range, a horizontal peaking circuit can be set to peak that portion of the signal.