The efficiency with which a video signal is encoded is increased by examining successive blocks of M picture elements to determine which K pels have frame differences which do not exceed a predetermined threshold. The values of these K pels are intentionally altered, and the pels are applied to a transform circuit which generates N.ltoreq.M corresponding coefficient values. Only N-K of the coefficient values, and a code indicating the unchanged pel locations are then encoded for transmission. Th...

A picture signal transmission system for transmitting after coding a picture signal obtained by scanning at least one picture to be transmitted, in which a difference between a representative level value of each picture element unit formed by at least one picture element and a forecast value obtained in accordance with a predetermined rule and based on a representative level value of adjacent ones of said picture element units is detected, and in which first level information and second level in...

A video signal transmission system for reduced bandwidth transmission defines each picture frame to include at least two picture element series A.sub.ij, B.sub.ij, . . . A regularly selective transmitter selects the video picture element signals of a given series, in succession for all such series, in corresponding, successive picture frame periods, the selected signals being predictively coded for transmission. In the receiver, a frame memory stores the predictively coded signals for all pictur...

When a video signal is encoded using differential pulse code modulation (DPCM) techniques, the frequency of occurrence of the various quantizer output or representative levels is non-uniform; usually, low levels occur more frequently than high levels, and this characteristic can be used to advantage by applying the DPCM output to a variable length encoder before transmission. The present invention increases this advantage by intentionally forcing the quantizer output to particular levels when do...

A picture transmission system for transmitting a video signal of compressed bandwidth, in which the transmitting station is provided with: means for dividing a picture to be transmitted into a plurality of blocks and regularly scanning and extracting video signals at corresponding sampling points in the respective blocks in a predetermined order; a frame memory for storing video signals of one frame; means for comparing picture elements of the video signals from the scanning and extracting means...

A receiver for receiving non-redundant pulse coded lines of a TV waveform. The non-redundant lines are received along with address information identifying the position of the respective lines in a TV frame. The address information controls the writing of the pulse coded lines into a frame memory. The entire contents of the frame memory is read out at the normal frame rate and converted into analog video information.

Immunity to transmission errors and worthwhile bandwidth reduction are achieved by distributing the difference signal, developed in differentially coding an image signal, over a spatially large interval or area, and transmitting the coded distributed signal instead of the image or differential signal. Line or frame image difference signals are, accordingly, dispersed by transformation prior to coding, e.g., by quantizing, and transmission, preferably by means of the Fourier, Hadamard, or other u...

In an encoding system for use with video signals, the velocity of a subject between two frames is estimated and used to predict the location of the subject in a succeeding frame. Differential encoding between this prediction and the actual succeeding frame are used to update the prediction at the receiver. As only the velocity and the updating difference information need be transmitted, this provides a reduction in the communication channel capacity required for video transmission. The scheme ma...

The system encodes a high rate digital video signal conveying picture elements into a low rate digital signal conveying words representative of some picture elements. The system comprises a frame store, a movement detector for detecting the movement area in one frame with respect to the preceding frame, a predictor, a bit distributing circuit for selecting the picture elements to be transmitted, a PCM encoder which encodes the DPCM words of the selected elements according to a quantization law a...

A technique for converting video information into sequences of digital words in a form which can be readily accepted by a computer. The generated digital words exclude some information content of the video signals which is not necessary for certain pattern recognition and control purposes. In accordance with the preferred embodiment of the invention, there is provided a clock having a rate which is in synchronism with the video line and field information. A comparator is provided for comparing t...