Showing papers on "Residual frame published in 1995"

Mode-specific method and apparatus for encoding signals containing speech

Abstract: A method for encoding a signal that includes a speech component is described. First and second linear prediction windows of a frame are analyzed to generate sets of filter coefficients. First and second pitch analysis windows of the frame are analyzed to generate pitch estimates. The frame is classified in one of at least two modes, e.g. voiced, unvoiced and noise modes, based, for example, on pitch stationarity, short-term level gradient or zero crossing rate. Then the frame is encoded using the filter coefficients and pitch estimates in a particular manner depending upon the mode determination for the frame, preferably employing CELP based encoding algorithms.

Frame synchronization in multicarrier transmission systems

Abstract: A discrete multitone modulation transmission system is described in which frame synchronization is monitored at the receiver by correlating frequency domain complex amplitudes of a synchronizing frame with a stored synchronizing pattern. If the correlation result falls below a threshold, indicating a loss of frame synchronization, a plurality of correlations are performed, in each case using the stored complex amplitudes of the synchronizing frame multiplied by a respective complex value representing a respective complex derotation corresponding to a respective possible time shift of the synchronizing frame. The best correlation result, if it exceeds another threshold, indicates a time shift for restoring frame synchronization, this being possible before the next synchronizing frame is received.

Apparatus for translating frames of data transferred between heterogeneous local area networks

Abstract: A translation engine for translating frames of data from one frame format to another frame format in the same manner as an IEEE 802.1D MAC-layer transparent bridge as required when transferring frames of data between interconnected heterogeneous local area networks. The translation engine is comprised of a variable length data pipeline capable of maintaining a constant synchronous data stream comprising frames of data from the input to the output of the data pipeline, without introducing any gaps in the data stream caused by removing fields of a frame, or causing the data stream to halt by inserting fields of a frame during translation of a frame from one frame format to another frame format.

Method and apparatus for improving the quality of images for non-real time sensitive applications

Abstract: A method and apparatus for improving the quality of images for non-real time sensitive applications are disclosed. A preprocessing unit receives a first frame from a input line. The preprocessing unit calculates a difference value between the first frame and a previously-received-frame. The preprocessing unit sends the first frame to a buffer unit coupled to the preprocessing unit. The preprocessing unit sends the difference value to a statistics unit coupled to the preprocessing unit. Using the calculated difference value, the statistics unit determines whether the first frame contains a scene change. The statistics unit generates a strategy for encoding the first frame based on the criteria of whether the first frame contains a scene change and whether the first frame is used in a still image or a moving image. A video coder-decoder coupled to the statistics unit and the buffer unit receives the first frame and the strategy for encoding the first frame simultaneously. The video coder-decoder operates to encode the first frame using this strategy.

System and method of generating compressed video graphics images

Abstract: A hybrid system for synthesizing a compressed video bitstream from a dynamic 3-D model has been realized. The video bitstream represents an image sequence comprised of a plurality of image frames which are sequential in time and in which each image frame is partitioned into a set of regions. Motion vectors are generated for each region within a current image frame which represent the dynamic 3-D model. A prediction error is computed for each region based on the generated motion vectors. The type of encoding to be performed on each region in a succeeding image frame is determined based on the value of the prediction error. Each region in the succeeding image frame is encoded as indicated by the determined encoding type.

Subsampled frame storage technique for reduced memory size

Abstract: A video compression system in accordance with the present invention may use a frame buffer which is only a fraction of the size of a full frame buffer. A subsampler connected to an input of the frame buffer performs 4 to 1 subsampling on the video data to be stored in the frame buffer. This allows the frame buffer to be one-fourth the size of a full frame buffer. The subsampling may even be 9 to 1, 16 to 1, or another ratio, for a concomitant decrease in frame buffer size. An upsampler is connected to the output of the frame buffer for providing interpolated and filtered values between the subsamples. Novel methods of filtering and interpolating performed by the upsampler are described. A new motion estimation technique is also described herein which directly detects the number of bits required to be transmitted to convey the difference between the predicted video data and the current video data, where a fewer number of bits used to convey the difference corresponds to better motion estimation. The search criterion for the best estimate of movement of a block is the minimum number of bits for conveying this difference.

Delay control for frame-based transmission of data

Abstract: A network for transferring packet data in a frame structure, preferably mixed with isochronous data. The frame structure is a continuously repeating structure, with each frame having a number of time slots. Certain ones of the time slots are available for transmitting packet data. The packet data is re-timed, e.g., by using a FIFO to output the data nibble-wise as required by the frame structure. Information about variability in delays at the transmitting end is sent to the receiving end. The receiving end uses the information to eliminate the variability, such as by a variable delay FIFO, thus restoring/recreating the original packet and IFG timing. Preferably, the frame structure is translated to and from a packet structure to permit the present invention to be used with previously available packet circuitry such as a media access controller and a hub repeater circuit.

Method and apparatus for encoding/decoding a video signal

Abstract: A video signal encoding apparatus determines quasi-feature points on the current frame based on sleeted feature points on the previous frame. A predicted current frame is obtained based on a number of triangle regions formed by the quasi-feature points. After determining a frame difference signal by subtracting the predicted current frame signal from the current frame signal, a plurality of processing regions are selected from the frame difference signal based on the magnitude of average pixel difference values corresponding to the triangle regions. Only the selected processing regions are then encoded for transmission to thereby reduce a transmission rate. A video signal decoding apparatus comprises corresponding circuits for decoding the selectively encoded video signal.

Video encoding method and system which encodes using a rate-quantizer model

Abstract: A system and method for determining quantization level versus bit-rate characteristics of raw video signals in video frames during a pre-encoding phase for video technologies such as MPEG and MPEG-2. During a pre-encoding phase, various quantization levels are assigned to various parts of a frame, and the frame is then pre-encoded to determine a bit-rate for each quantization level used in the pre-encoding phase. Depending on the embodiment, quantization levels are assigned in one of many ways: checkerboard style, block style or any other distribution that avoids statistical anomalies. The method and system repeat the pre-encoding for plural frames, recording all quantization level versus bit-rate statistics on a frame by frame basis. These statistics are then used during encoding or re-encoding of a digital video to control the number of bits allocated to one segment of the digital video as compared to another segment, based on a target quality and target storage size for each segment. The resulting encoded digital video is stored on a digital storage medium, such as a compact disc.

Synchronizing waveform generator

Abstract: A multiplex frame format for transmitting digital data in a data transmission system comprises a PACKETS portion comprising a highly error-protected region and a region having only Reed Solomon encoding as an error protection measure, the PACKETS portion including low speed data. The frame format also comprises portions for transmitting medium (AUDIO) and high speed (VIDEO) data streams following the PACKETS portion. Prior to transmission, the composed frame comprising the PACKETS, AUDIO and VIDEO portions is interleaved and the BLOCK SYNC and FRAME SYNC are added. A multiplex structure control packet word of the PACKETS portion immediately follows FRAME SYNC. Thus, the FRAME SYNC word defines where interleaving begins. A demultiplexer in concert with a microcontroller of a decoder decodes the multiplex structure control word and related PACKETS and outputs digital data streams to related output peripheral processors. The BLOCK SYNC word preferably comprises one eight bit byte and contains network signaling or other data at predetermined bit positions within the word. Moreover, the frame format is flexible and may vary in horizontal and vertical dimensions as digital service streams are varied due to service requirements or priorities. The multiplexers for forming the frame according to the present invention may be arranged in redundant (hot standby) or in multi-service arrangements synchronized by a synchronizing waveform, digitally generated to comprise a continuous 3.375 MHz portion and a single cycle frame marking signal of greater magnitude but significantly lower frequency.

Frame synchronizing apparatus for quadrature modulation data communication radio receiver

Abstract: In a frame synchronizing apparatus for a receiver apparatus of a digital data radio communications system in which data are transmitted in frame periods with a fixed data sequence contained each frame, a data correlation circuit obtains successive sequences of values of vector difference between vector values constituting a demodulated digital baseband signal, and successively compares these sequences with a fixed vector difference sequence corresponding to the fixed data sequence, to derive a correlation signal substantially unaffected by any phase rotation in the baseband signal. A frame synchronizing circuit formed as a PLL for generating a frame synchronizing signal, includes a phase comparator which periodically indicates whether a detected phase difference between the correlation signal and frame synchronizing signal is effectively zero, positive or negative, and a counter holding a count value indicating a cumulative phase error between these signals. So long as the detected phase differences are successively effectively zero and the cumulative phase error is sufficiently small, the phase of the frame synchronizing signal is held unchanged, thereby achieving a high degree of phase stability.

Method and apparatus for efficient addressing of DRAM in a video decompression processor

Abstract: Pixel data is stored and subsequently read from a random access memory of a video decompression processor in a manner that reduces the number of times different rows of the RAM must be addressed in order to retrieve portions of the pixel data therefrom. Pixel data from a video frame is stored in the RAM as a plurality of pages. Each page substantially fills a different row of the RAM and corresponds to a different section of the video frame. A motion vector is decoded to determine the location of a prediction area within the video frame. In the event that the prediction area encompasses more than one of the pages of the video frame, the pixel data is retrieved one page at a time, minimizing the number of row changes required when addressing the RAM to retrieve the data.

Image processing system using pixel-by-pixel motion estimation and frame decimation

Abstract: An image processing system for processing a video signal includes an encoder and a decoder, wherein the encoder comprises a frame decimator for selecting a plurality of frames from said video signal, a unit for creating M number of candidate frames for each of the non-selected frames, i.e., skipped frames by using M number of skipped frame prediction factors, and a unit for comparing each of the N skipped frames with each of the candidate frames to transmit a skipped frame prediction factor for each of the N skipped frames to the decoder; and the decoder comprises a unit for deciding each of the N skipped frames between the previous frame and the reconstructed current frame by using the transmitted skipped frame prediction factor.

Method and apparatus for encoding a video signal using pixel-by-pixel motion prediction

Abstract: An apparatus for determining a preducted current frame based on a current frame and a previous frames comprises: a unit for selecting a number of pixels from the pixels contained in the previous frame to detect a first set of motion vectors; a unit for producing a second set of motion vectors for all of the pixels contained in the current frame by using first set of motion vectors; a unit for assigning the value of each of the pixels in the previous frame as the value of one of the pixels in the current frame by using the second set of motion vectors, to determine a preliminary preducted current frame; a unit for finding the difference between the current frame and the preliminary preducted current frame to detect collective error regions; a unit for selecting one pixel amount the pixels contained in each of the collective error regions; a unit for detecting a third set of motion vectors for the selected pixels from the collective error regions; a unit for producing a fourth set of motion vectors for all of the pixels contained in the current frame by using the first set of motion vectors and the third set of motion vectors; and a unit for assigning the value of each of the pixels in the previous frame through one of the fourth set of motion vectors, as the value of one of the pixels in the current frame.

Video format conversion process and apparatus

Abstract: A method and apparatus is provided for converting the frame rate of digital video data from one frame rate to another frame rate without introducing motion artifacts into the converted video data stream. A high frame rate video stream is converted into a lower frame rate video stream by selecting whole frames from the high frame rate video stream and outputting the selected frames as the lower frame rate video stream. To insure that only whole frames are selected from the high frame rate video stream, the frame rate of the high frame rate video stream is locked to the frame rate of the lower frame rate video stream. A frame cycle is defined to be an integer number of frames in the higher frame rate stream. The higher and lower frame rates are locked by repeatedly selecting and outputting as the lower frame rate video stream, over a time period that is substantially equal to one frame cycle, an integer number of frames from each frame cycle of the higher frame rate.

Improved definition video frame enhancement

Abstract: The human visual system seems to be capable of temporally integrating information in a video sequence in such a way that the perceived spatial resolution of a sequence appears much higher than the spatial resolution of an individual frame. This paper addresses how to utilize both the spatial and temporal information present in an image sequence to create a high-resolution video still. A novel observation model based on motion compensated subsampling is proposed for a video sequence. Since the reconstruction problem is ill-posed, Bayesian restoration with an edge-preserving prior image model is used to extract a high-resolution video frame from a low-resolution sequence. Estimates computed from an image sequence containing a camera pan show dramatic improvement over bilinear, cubic B-spline, and Bayesian single frame interpolations. Improved definition is also shown for a video sequence containing objects moving with independent trajectories.

Method and apparatus for encoding a video signal using feature point based motion estimation

Abstract: An apparatus for encoding a digital video signal (217) to reduce a transmission rate of the digital video signal, which comprises a feature point based motion compensation circuit (150) for selecting a set of feature points from the reconstructed reference frame to detect a set of motion vectors between a current frame and an original reference frame corresponding to the set of feature points by using a feature point based motion estimation, and for generating a second predicted frame based on the set of motion vectors and the reconstructed reference frame. The feature point based motion estimation employs a convergence process in which a displacement of each of the feature points are given to a motion vector thereof and the six triangles of each of the hexagon are affine-transformed independently using the displacements of their vertex feature points. If the displacement provides a better peak signal to noise ratio (PSNR), the motion vector of the subject feature point is sequentially updated. Therefore, the inventive convergence process is very efficient in the matching process to determine the predicted image as close as possible to the original image having zooming, rotation or scaling of objects.

Video event trigger and tracking system using fuzzy comparators

Abstract: A video observation method and apparatus, the apparatus having a frame storage mechanism, a dividing mechanism, a plurality of fuzzy comparators and a trigger signal mechanism. The frame storage mechanism stores at least one non-current video frame of a viewing field. The dividing mechanism divides a current video frame of the viewing field and the at least one non-current video frame into a plurality of corresponding trigger sections. The plurality of fuzzy comparators each compare and detect a fuzzy logic difference between one trigger section of the current video frame and the corresponding trigger sections of the at least one non-current video frame, the number of fuzzy comparators being selected so that every trigger section of the current video frame is compared. The trigger signal mechanism provides a trigger signal when a fuzzy logic difference is detected between any of the corresponding current and non-current trigger sections. A video observation mechanism and data reducing mechanism may be included with the above apparatus or alone with only a frame storage mechanism, a single generic comparator and a trigger signal mechanism. The video observation mechanism provides a video data stream, wherein each pixel of each frame of a viewing field is provided as multiple bits of data. The data reducing mechanism reduces each set of multiple bits of data which correspond to each pixel to one bit of binary data based on whether the pixel has a level of grey which is above or below a threshold level of grey.

Dram mapping for a digital video decompression processor

Abstract: A random access memory of a digital video decompression processor is mapped to enable the reconstruction of successive video frames of pixel data represented by a compressed video bitstream. A FIFO buffer is provided in the RAM for the compressed video bitstream. A first luminance anchor frame buffer and a first chrominance anchor frame buffer are provided for storing a full frame of luminance data and a full frame of chrominance data for a first anchor frame used to predict B-frames. A second luminance anchor frame buffer and second chrominance anchor frame buffer are provided for storing a full frame of luminance data and a full frame of chrominance data for a second anchor frame used to predict the B-frames. A first B-frame luminance buffer is provided in the RAM and sized to store less than 100% of the amount of luminance data in a first B-frame field. A second B-frame luminance buffer is provided in the RAM and sized to store at least 100% of the amount of luminance data in a second B-frame field. A B-frame chrominance buffer is provided in the RAM to store at least 100% of the amount of chrominance data in a B-frame. The anchor frames and B-frames are read from the RAM to enable the reconstruction of successive video frames. The memory mapping is particularly well suited for the decompression of PAL formatted video in an MPEG-2 decoder.

Methods of and apparatus for encoding and decoding digital data for representation in a video frame

Abstract: Digital data comprised of bytes formed of a predetermined number of data bits are encoded for representation in a video frame. Each byte of digital data, or a portion thereof, is represented in a respective region of the video frame by one or more video component levels that are assigned to the region and which correspond to the numerical value of the data bits of the byte or of the portion. The digital data are represented in the video frames in place of a video image or, alternatively, are represented in the same frames in which video images are recorded but in the areas of the frame in which the video image is not ordinarily recorded. Digital data represented in the video frame are decoded from the video component levels assigned to the regions.

Video processing method and apparatus

Abstract: A video processing method and apparatus for processing video frames comprising animated images so as to blur movement of the animated images between successive frames, the method or apparatus comparing a first input frame with the following input frame; identifying moving areas in the first input frame by the comparison; calculating the velocity of the movement of the moving areas between the first and following input frame; summing, only for each input pixel site within the identified moving areas of the input frame, the pixel value of each input pixel site and adjacent pixel values determined according to the calculated velocities and a predetermined aperture type for the input frame; and providing an output frame from at least the summed pixel values and pixel values of areas of the input frame other than the moving area, the adjacent pixel values either being the pixel values of pixel sites in the input frame which are spatially adjacent in the direction of the velocity or predicted temporally adjacent pixel values for each input pixel site for times intermediate the predetermined aperture time.

Method of reordering a decoded video picture sequence

Abstract: This invention details a new method of performing frame reordering for decoded digital video picture. By making use of the information on the incoming picture type and the location of the stored bi-directionally predicitive (B) coded, frame in the frame buffer, the frame sequencer can adaptively perform frame reordering for sequence with and without B frame. In addition, the frame reordering is achieved with shorter frame delay and with smaller frame memory.

Real time ultrasound endocardial displacement display

Abstract: An ultrasound display apparatus provides a two-dimensional display of a fluid filled cavity and surrounding wall tissue in the form of a sequence of pixel image frames that are shown on a display screen. The apparatus includes circuitry for indicating wall tissue displacements on the screen on a frame by frame basis. The apparatus includes a pixel classification circuit for classifying pixels in each pixel image frame into two types, i.e., tissue or fluid. A frame comparator determines which pixels change classification from one to another type as between a pair of succeeding frames. A color assignment circuit assigns to changed-type pixels in a frame, a color value which causes the changed pixels to be readily differentiated by a viewing user. Different color values are used from frame to frame on both ventricular expansion and contraction cycles.

System and method for focused-based image segmentation for video signals

Abstract: Motion video is represented by digital signals. The digital signals can be compressed by coding to reduce bitrate and thus save time and expense in transmitting and reproducing the video. The present invention is a system and method for reducing the amount of information required to satisfactorily reproduce video signals by distinguishing more pertinent portions of the video from less pertinent portions. In particular, edges are detected based on amplitude variations in the luminance characteristic of the picture elements. Sharp edges are deemed to be "focused". The portion of the video frame between the focused edges is deemed to be focused, as well. A template is created corresponding to the focused portion. A signal corresponding to the outline of the template is combined with the original frame signal to create a segmented frame signal. When motion detection information is available, a motion-based template may be created and intersected with the focus template. A signal corresponding to the outline of the intersected template may be transmitted with the frame signal as the segmented frame signal.

Method and apparatus for inverse 3:2 pulldown detection using motion estimation information

Abstract: Converting 24 frame per second film source material to 60 fields per second video involves converting one film frame into either two or three video fields using a repeating 3:2 field pattern, referred to as a 3:2 pulldown. When one film frame is made into three video fields, there will be a redundant video field. Once the source material has been transferred to video, the video is edited and distributed. When compressing video that was originally film source, the presence of the duplicate fields results in sub optimal compression. The highest efficiency compression can be achieved when the redundant fields are skipped and the frame rate is returned to that of the original film source. Thus, an inverse 3:2 pulldown, is necessary to identify and remove the redundant video fields before the video is compressed. To identify the redundant video fields, a method and apparatus is disclosed that generates motion vectors and error displacements for adjacent video fields. The motion vectors and error displacements are analyzed and a determination is made whether the video fields are redundant.

Method and apparatus for efficiently determining a frame motion vector in a video encoder

Abstract: A method of implementing a fast video encoder by approximating a frame motion vector is introduced. MPEG-2 encoding uses both field and frame vectors in the encoding process. To implement an encoder in an efficient manner, an approximated motion vector created from two field motion vectors is used. The frame motion vector may be determined using the two field motion vectors alone, or by using the two field motion vectors in conjunction with their respective absolute error values. By using the disclosed methods, a motion estimation part for generating frame motion vector is not necessary. Only two field motion estimation parts are required to determine the field motion vectors, the frame motion vector is then approximated using the two field motion vectors. The cost and complexity of a digital video encoder system is thereby reduced.

Content based video compression system

Abstract: A content based method of compressing a segment of video is implemented in two stages. In a spatial integration stage, figures are represented in terms of compact models. In a temporal integration stage, which uses the information from the spatial integration stage, constructs, i.e., world images and data describing relationships between world images and frames, are generated. In operation, each frame in a series of frames is preprocessed to tessellate any moving figures and to obtain motion data for the moving figures and for the image background. The figure motion data is stored in a manner so as to associate the motion data with the original frame. Frame information identifying the size and position of each frame with respect to a background world image is also stored. Each tessellated figure is compared to the original frame to produce a template for each moving figure and a template for the background. Each template is compared to a world image that is associated with that template so that material common to both can be cut and the remaining material added to form a new world image. The steps are repeated until all frames in the segment are processed. The resulting world image data, figure motion data, and frame information are output for transmission or storage. The world image data may be compressed prior to transmission or storage.

Apparatus and method for detecting frame synchronization pattern/word in bit-stuffed digital data frame

Abstract: A frame sync acquisition mechanism accurately locates a frame synchronization word within successive selectively bit-stuffed frames of data by not only looking for the frame sync word in the two expected alternative frame sync word locations based upon either the addition of stuff bits or the lack of such stuff bits, but also selectively examining a pair of additional potential locations, one of which precedes and the other of which succeeds the two expected alternative frame sync word locations. If an exact match with the frame sync word is located in either of the expected locations, that location is selected as the reference for the next succeeding frame. During the search of the next successive frame and for every succeeding frame, an attempt is made to initially match the frame sync word with in either of these expected locations. If unable to do so, the search is expanded to encompass the entire window of location uncertainty, so as to include the two additional locations. During this expanded search, that location which yields the smallest number of bit errors is declared as the reference location for the next succeeding frame. If there is a failure to find an exact match over the course of a plurality of successive frames, an out-of-sync condition is declared, and the frame sync acquisition of mechanism is re-initialized.

Frame synchronizing device

Abstract: A frame synchronizing device for discriminating a time slot location for each channel of time-division multiplexed signals is disclosed. The frame synchronizing device according to the invention processes time-division multiplexed signals in parallel in a STM-4C(Synchronous Transport Module-4 Concatenation) of the Broadband Integrated Service Digital Network according to the ITU-T recommendation, such that the searching of frame synchronization can be achieved by detecting frame bytes on data being received at a high speed in the STM-4C structure to align the bytes based on the detected time interval, converting the frame data into the 8-bits parallel data and then detecting, in sequence, the frame bytes at a lower speed clock being divided by 8, thereby providing a simplified, less power consumptive frame synchronizing device in the STM-4C structure according to the ITU-T recommendation.

Information encoding method and apparatus, information decoding method and apparatus and recording medium

Abstract: A method of encoding information of an input signal using a fixed number of bits for each unit time frame. Part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame is contained in the encoded information of the first frame. This eliminates fluctuations in the sound quality due to bit surplus/shortage resulting from quantization for achieving efficient encoding and decoding.