Abstract: In a recording system, a sequence of image signals obtained from a sequence of images are used to generate and record a sequence of recordable signals on a read only memory. Efficient coding of the received sequence of image signals is carried out through the use of a given parameter which is adaptively and dynamically changed, preferably manually, through a parameter controller acting as the interactive device. The image signals are repeatedly subjected to the efficient coding process. The process uses a sequence of predictive signals to produce coded signals. The predictive signals are displayed on a monitor display device to be monitored by an operator. The operator changes the attributes of the parameter until an optimum image is obtained. The optimum parameter is stored on a magnetic tape.

Abstract: In an image recording system for use in recording a sequence of coded signals on a recording medium, such as a CD-ROM in response to a sequence of image signals divisible into a succession of frames each of which is subdivided into a plurality of splits, the image signals are selectively subjected to interframe coding and intraframe coding in a coder to be coded into first and second error signals, respectively, under control of a coding control circuit. The intraframe coding may be carried out about a selected split at every frame, at every preselected period, or at predetermined positions of each scene. The second and the first error signals are rearranged into the coded signals by delaying the second error signal relative to the first error signal. Such a second error signal serves to reproduce an initial image on reproducing the coded signals and enables a reverse reproduction, a quick search, a high speed reproduction, and the like in a reproducing system.

Abstract: In a teleconferencing system, a video encoder at the transmit end of the system includes a frame memory for storing video samples of a frame of a motion-picture signal and reading video samples at frame intervals. For still-picture transmission, an encoder circuit translates video samples read out of each successively shifted location of the frame memory which corresponds to at least one scanning line period of the frame into a signal representative of an intraframe correlation between adjacent video samples and generates a signal of a constant value during remaining line periods of the frame. For motion-picture transmission, video samples of the motion-picture signal for at least one scanning line period are translated into a signal representative of the intraframe correlation and video samples of remaining line periods of each successive frame are translated into a signal representative of the interframe correlation between successive frames.

Abstract: In an image coding system having a plurality of coding characteristics, such as quantization characteristics, information of a digital image signal sequence is monitored in each of a number of predetermined intervals by forming a histogram of a sequence of coefficients which is calculated from the digital image signal sequence in accordance with each of the coding characteristics. The amount of information is calculated by summing up the coefficients in relation to every one of the coding characteristics. An optimum one of the coding characteristics is indicated by the coding control circuit to code the coefficient sequence into a sequence of coded signals in accordance with the optimum coding characteristic. The coefficient sequence in each frame may be divided into a sequence of blocks each of which is judged to be either valid or invalid in relation to each coding characteristic. Results of judgement may be included in the amount of information.

Abstract: In an image communication system, an input image sequence is converted into a block-formatted sequence. A data compression signal indicative of the amount of moving blocks in the block-formatted sequence is generated to individually control a plurality of vector quantizers each having a particular frequency band and a memory containing output vectors. The output vectors of each of the vector quantizers is representative of inverse orthogonal transform of a code table of optimum quantized vectors in the particular frequency band, the optimum quantized vectors being orthogonal transform of interframe differential training image sequences. The output vectors is retrievable from the memory as a function of an interframe differential image sequence, or prediction error.

Abstract: A motion compensation difference interframe or intra-frame coding system includes a block data redundancy compression and coding unit, a PIXEL data coding unit and a prediction data generator unit. The block data redundancy compression and coding unit codes a motion compensated (MC) difference between an input image in a block and a motion predicted image from the prediction data generator unit, and transmits coded data to a receiver. The PIXEL data coding unit receives an error between the MC difference and a decoded MC difference from the block data redundancy compression and coding unit, rearranges the error in PIXEL data and codes the PIXEL error, when the error is greater than a predetermined value. The PIXEL coded data is also transmitted to the receiver. The prediction data generator unit generates predicted block data of the motion of the image. The redundancy compression and coding unit may include a filter circuit rejecting pulse components contained in the MC difference.

Abstract: In a predictive encoder for use particularly in a conference television system, a signal processing unit is used in producing a prediction signal and comprises three prediction circuits (22, 23, 31) and a selection circuit (24) coupled to the prediction circuits. The prediction circuits are for producing an inframe, an interframe, and a background prediction signals, respectively. Those signals are produced by processing an original signal at instants which precede a current instant and are different from one another. The selection circuit is for selecting one of the inframe, the interframe, and the background prediction signals. Therefore, it is possible to produce the prediction signal suitably predictive of the original signal. The signal processing circuit serves equally well in a predictive decoder.

Abstract: In coding a digital video signal representative of successive pictures by using correlation between the successive pictures, each picture is divided into a predetermined number of blocks of picture elements. An original motion vector is used to represent a movement of each block between two pictures. The digital video signal is predictively coded by using the original motion vector to produce a coded signal. An on-off control signal is produced in order to determine whether or not subsampling is carried out at each of the blocks. A part of the coded signal is subsampled into a subsampled signal with reference to the on-off control signal and a remaining part is left as it is as a non-subsampled signal. The subsampled and the non-subsampled signals are code-converted into a converted code signal. The original motion vector and the on-off control signal are code-converted into a converted motion vector signal and a converted control signal which is distinguishable from the converted motion vector signal.

Abstract: A code conversion system for picture signals, e.g., television signals. In accordance with this system, an operation is made to select a coding parameter by using N scanning lines of the picture signal as a unit so as to encode the picture signal by using the coding parameter. When coding operations with respect to the picture signal carried out every N scanning lines are repeated in succession to provide the same coding result, an operation is made to encode a repetition number of the coding operations, thus providing a code conversion system suitable for a low transmission bit rate of picture signals. Particularly, this system is greatly practicable when applied to a predictive coding system.

Abstract: In order to encode image signals using interframe correlation while maintaining high data compression as well as high resulting images, a motion compensated interframe prediction error is orthogonally transformed and then is subject to quantization. Thereafter, the quantized error signal undergoes inverse orthogonal transformation. In order to compensate for distortions caused by the quantization, a difference between the inversely orthogonally transformationed error signal and the original prediction error signal is quantized. By selecting the quantization characteristics, the influence or contribution of the orthogonal transformation can be controlled continuously.

Abstract: A video signal compression circuit for encoding a video signal to reduce the quantity of video information that is transmitted without loss of information and a video signal decompressing circuit for recovering the video signal from its compressed coded form. The encoding circuit includes means for detecting the motion contained in the video signal to generate motion vectors which are representative of this motion. Each picture frame produced from the transmitted video signal is divided into many block units. The motion vectors are generated according to the order of the block units rather than according to the order in which the video signal is transmitted. Thereafter, the vectors are reconverted to the order of the input video signal. The input video signal and the converted motion vectors are used for generating a prediction error signal which indicates motion in the video signal. The prediction error signal is encoded using a variable length coding scheme.

Abstract: On encoding a cluster and run sequence comprising clusters of non-zero signal elements and runs of zero signal elements into a code sequence with application of a compression encoding scheme selectively to the clusters and without application of the encoding scheme to the runs, a mode code is used to indicate application of the encoding scheme to each selected cluster and to represent a zero signal element next preceding the selected cluster in a next preceding run. In the code sequence, the mode code next precedes a succession of amplitude codes representative of the selected cluster and next succeeds a run length code preferably representative of that run length of the next preceding run from which the next preceding zero signal element is reduced. Alternatively, the mode code may indicate switching between application and non-application of the encoding scheme to partial sequences each of which starts with a cluster next succeeded by a run.

Abstract: A video signal compression circuit for encoding a video signal to reduce the quantity of video information that is transmitted without loss of information, and a video signal decompressing circuit for recovering the video signal from its compressed coded form. The encoding circuit includes means for dividing the video signal of each television frame into blocks, each block including a plurality of picture elements distributed over several scan lines. The information in each block is analyzed to detect image movement in that block and a movement detection signal corresponding to each block is produced. Thereafter, the movement detection signal is rearranged to have a time sequence which corresponds to the sequential order of the picture elements in the original video signal. With the help of the rearranged movement detection signal, the original video signal is coded in accordance with a predictive-coding scheme into a form which allows it to be transmitted over a television signal carrier.

Abstract: In an adaptive predictive coding apparatus for coding an input television signal so as to perform predictive coding by determining an optimum prediction function among a plurality of prediction functions for each of a plurality of blocks obtained by dividing up a frame of the input television signal, each of the blocks having a plurality of picture elements, and to perform selection of quantizing characteristic and coding control such as subline and subsample coding, data necessary for representing a given prediction function of the plurality of prediction functions and data necessary for representing a prediction error amount per the block for the given prediction function are evaluated. Sums of evaluated data are compared to produce, on a block by block basis, one of the prediction functions which provides a minimal sum as an optimum prediction function.

Abstract: In an adaptive predictive coding system for television signals in which one optimum prediction function is selected in block unit from a plurality of prediction functions alloted to a plurality of blocks each consisting of a plurality of picture elements which divide each frame for the television signal and the optimum prediction function is used for predictive coding of the television signal, a motion vector is determined in accordance with both motion vector information and prediction error information, so that the efficiency of coding can be remarkably improved especially where the transmission speed is low.

Abstract: A coded video signal transmitting and receiving system comprises in combination a coding apparatus using a plurality of prediction functions and provided for a transmitter, a decoding apparatus provided for a receiver, and a coded signal transmission path, whereby a coded video signal transmitted from the coding apparatus via the transmission path is received at the decoding apparatus and decoded thereby. In the coding apparatus, from a video signal received in time series, two dimensional blocks each consisting of a plurality of picture elements which extend over a plurality of scanning lines are formed, and the video signal is delivered out in a different sequence from that of the input time series. A predictive error value per block with respect to arbitrary one of the plurality of prediction functions associated with each block is generated, and a prediction function to generate a subsequent prediction error value is designated by use of part or all of prediction error values.

Abstract: A television signal coder of the type which makes use of correlations to compress the amount of information transmitted. n fields are selected for every m fields (m, n being positive integers; m>n), and a predicted signal level for each picture element in the n fields is represented by an interpolated value of the respective spatially corresponding picture elements in the preceding and succeeding fields. The prediction error which is the difference between the interpolated value and each corresponding picture element is coded and transmitted. The signal for the remaining (m-n) fields are coded and transmitted according to conventional coding systems.

Abstract: A predictive encoder produces a prediction error signal in response to an autocorrelated signal, such as a television broadcast signal. The encoder includes a prediction signal producing circuit for producing several prediction signals for each sample element of the autocorrelation signal. The several prediction signals comprise preferably a single intraframe prediction signal and a group of interframe or interfield prediction signals. The group of prediction signals are compared with the sample element of the autocorrelation signal to produce a selection signal indicative of which one of the group gives the best approximation of the autocorrelated signal. The prediction signal of the group giving the best approximation along with the intraframe prediction signal are selected out of the total number of prediction signals. A further selection is made between the two first selected prediction signals according to a prediction error signal.

Abstract: A television signal coding system is designed to avoid any increase in the volume of information transmitted resulting from transmission of unnecessary picture elements, while at the same time reducing the volume of address information required. The picture elements are compared one by one between successive frames, and the magnitude of the frame-to-frame differences is compared with a predetermined threshold value to determine whether the change is significant or not. A predetermined number of consecutive picture elements forms a unit region. A line of horizontal scan is divided into regions, each including a predetermined number of unit regions, and for each of such regions the decision is made as to whether it includes at least one significant unit region or not. Each of the significant regions is further divided, and for each of the resulting divisions the decision is made as to whether it is significant or not.