Abstract: An encoding/decoding system for sequentially encoding input digital signals and sequentially decoding the encoded signals on the basis of the frequency of occurrence of the input digital signals, thereby improving an encoding efficiency. In a variable length encoding/decoding system, sequential lists of encoded values are used in an encoder and sequential lists of decoded values are stored in a decoder for utilizing the frequency of occurrence of the signals. In a vector quantization encoding/decoding system, the frequency of occurrence of input image signals is used to produce code books for storing vectors that are adjacent to an input vector and to form a block using the input image signals located in the same area in consecutive frames.

Abstract: A subnyquist sampling filter which results in less loss of picture resolution. An adaptive prefilter perform low-pass filter processing on a series of picture signals sampled in the form of a square lattice in a direction in which it has been determined that the degree of change of the picture signal at the periphery of an extracted picture element is a minimum. An adaptive interpolation filter performs interpolation processing on the picture signal obtained by subnyquist sampling with a subsampler the picture signal output from the adaptive prefilter in the direction where the degree of change of the picture signal level at the periphery of the abstracted picture elements is a minimum.

Abstract: A transformation coding device which applies high by efficient coding to a digital image signal, and in which a plurality of quantization characteristics are prepared and one quantization characteristic is adaptively selected in accordance with a predicted distortion for an input signal and a sequence of transformation coefficients, thereby allowing the quantization to be performed in accordance with statistical properties of an input signal to be implemented, and at the same time, allowing a signal to be efficiently compressed.

Abstract: An interframe video data coding and decoding apparatus utilizes a differential amplitude suppression circuit in combination with a block encoder and a motion detector to non-linearly suppress amplitude values of interframe differential block data based on a motion detection threshold value determined by an encoding control circuit. The determined threshold value is based on the amount of encoded data being stored in a transmission buffer memory. The suppressed amplitude differential block data is added to corresponding blocks in a frame memory to update the contents of the frame memory during each frame of input video data. In another embodiment, vector quantization encoders are utilized to transmit a motion vector index with encoded frame differential data.

Abstract: Various filter circuits for processing digitized color television signals are disclosed. Particularly, there are disclosed several embodiments of a luminance/chrominance signal separating filter with which separated, digitized luminance and chrominance are derived with a minimum amount of interference therebetween by determining the direction from a given point in which there is a minimum amount of change in the digitized image signal. Also, there is disclosed a subnyquist sampling filter which operates upon this same principle.

Abstract: A picture signal encoding and decoding apparatus which transmits a digital picture signal by encoding, and receives and decodes an incoming encoded signal comprises a configuration in which a condition not to make a receiving buffer overflow can be controlled on the transmitting side, and a plurality of quantizers are prepared and a proper quantizing characteristic is selected and used according to the sequence of transformed coefficients and the size of a motion vector. Therefore, it is not necessary to prepare a receiving buffer of a large capacity or a high speed decoding circuit, so that the apparatus can be manufactured at a low cost and the stability of operation is improved and also a signal can be compressed efficiently owing to the realization of quantization corresponding to a statistical characteristic of an input signal.

Abstract: In an image coding and decoding device, input digital image signals are divided into blocks of prescribed size, and coding processing is performed on differential signals taken between the input block signal and interframe forcasting signals thereby enabling efficient transmission to be performed.

Abstract: In an interframe adaptive quantization encoding apparatus to perform efficient encoding of video signals using vector quantization method, analog signals raster-scanned from the left to the right on the screen and from the upper side to the lower side are converted into digital signals, the digital signals per every m picture elements x n lines are made a block and the block data is subjected to mean value separation in a vector quantization encoder thereby input vector is formed, inner product between the input vector and output vector read from a code book ROM is estimated by an inner product operation circuit, and maximum value of the inner product is estimated by a maximum inner product detection circuit and made amplitude coefficient, thereby efficient encoding is performed.

Abstract: A vector quantizer for quantizing the vector of image and audio information, the vector quantizer being capable of efficiently encoding a compensation predictive error signal at a reduced bit rate by performing adaptive vector quantization after judging the significance of the compensation predictive error signal in blocks, and capable of movement compensation inter-frame vector encoding in which variable-length encoding of movement vector is facilitated and information production control is achieved easily.

Abstract: A vector quantizer receives a plurality of input signals in block form and operates to determine an output vector having the least distortion with respect to an input vector by various techniques. A coded output or output vector codetable address is output from a coder of the device for receipt by a decoder which constructs a proper output vector signal.