Abstract: The invention provides a recording and/or reproduction apparatus and a recording and/or reproduction method by which information can be recorded or reproduced accurately onto or from any of a plurality of record layers of an optical disk. In the recording and/or reproduction method, after an optical disk is started, an optimum focus offset position for a predetermined record layer of the optical disk is searched for. This searching is performed by varying an offset value stepwise and searching for an offset value with which the amplitude of a tracking error signal exhibits a maximum value. After an optimum focus offset position is searched out, the value of it is stored. Similar processing is performed also for any other record layer. When an instruction to reproduce a predetermined record layer is developed in step, focus jumping to the record layer is performed. Then, an optimum focus offset value searched out and stored in advance is read out and added to a focus error signal.

Abstract: The present invention provides digital signal encoding method and apparatus, a digital signal recording medium, and digital signal decoding method and apparatus which improve error correcting capabilities and reduce redundancy with a simple structure when the digital signal is encoded and decoded by adding an error correction code. By increasing the code length, the correction parity number, and the interleave constraint length more than the compact disc standard when the digital signal is encoded by adding an error correction code, the redundancy can be reduced and the size of data that can be recorded can be increased.

Abstract: An encoder considers a frame representing a picture as comprised of areas. For each area, the encoder decides which of frame-based or field-based orthogonal transformation will be most efficient at reducing spatial redundancy in that area. For each area, the encoder decides which of frame-based or field-based predictive encoding will be most efficient at reducing temporal redundancy in that area. The encoder encodes each area of the picture frame using the most efficient orthogonal transformation technique and using the most efficient predictive encoding technique to produce an encoded signal. A decoder decodes the encoded signal. The encoded signal is recorded on a recording medium, transmitted over a transmission channel, or broadcast.

Abstract: A motion detecting apparatus in which when pixels within a search range formed of a predetermined number of pixels and pixels within a reference data block the number of which is smaller than the predetermined number of pixels in the search range, are compared on the basis of the arrangement state thereof, a processing circuit processes sums of difference absolute values of respective pixels within the reference data block and corresponding pixels within the search range formed at every search range, to thereby detect a motion state on the basis of the sums. Respective pixels within the search range are input to the processing circuit at a set time and pixels within the search range are input to the processing circuit at the set time, thereby being sequentially processed with corresponding pixels within the data block.

Abstract: An apparatus for coding a moving picture in which one frame is comprised of two fields, includes a coder such that, with respect to all blocks in a frame, the odd field (the first field) and the even field (second field) are divided into blocks, thus permitting motion prediction of the second field from the first field, a coder means adapted for switching, every macro block, whether or not a frame is divided into the first field and the second field to generate block data to adaptively switch these coders every frame, thereby making it possible to obtain a picture of a high picture quality with a lesser quantity of information, to reduce the scale of hardware, and to reduce the capacity of a decoder.

Abstract: A motion vector detecting apparatus using the minimum residual difference between corresponding picture elements from two consecutive frames and an interpolation circuit to develop a moving vector with half-picture-element pitch accuracy. A residual difference is obtained by comparing each frame of an image signal fed into the apparatus with each previous frame. A solution vector is obtained by taking the minimum value of the absolute values of the residual differences. The solution vector is adjusted by a correction value, which is determined by interpolating extreme values in the vicinity of this solution vector and taking a minimum therefrom, to obtain the half-picture-element pitch solution vector.

Abstract: In connection with compression-coding of video signals on the basis of inter-frame correlation, a single reference table is used for variable length encoding of inter-frame motion vectors established on the basis of various motion vector value ranges and degrees of accuracy. A reference table is provided for variable length encoding motion vectors based on a particular value range and degree of accuracy. In order to use the same table for motion vectors based on a larger value range than that for which the table was designed, the value of a motion vector to be encoded is divided to form a quotient and a remainder. An addition bit code is formed on the basis of the remainder and is appended to a variable length code which corresponds in the reference table to the quotient so that a variable length code value is formed for the motion vector based on the larger range.

Abstract: An apparatus for detecting motion of blocks by block matching of detecting a matching degree of corresponding positions between pictures. The device comprises integrators 12 each having a calculating unit for calculating picture positions taking into account a motion vector and an angle of motion between blocks subjected to matching and an accumulator for finding and accumulating absolute values of differences for the respective picture positions, and a decision circuit 13 for collecting outputs of the integrators 12 for each of macro-blocks as a unit and finding the smallest of the integrator outputs. With the present apparatus, not only the motion vector but also the angle of motion can be detected. Therefore, if the apparatus is applied to a picture encoding and decoding system, motion compensation may be achieved effectively for pictures not only performing a translatory movement but also changing in the angle of motion.

Abstract: Video signal transmitting system in which digital video signal are divided into groups of predetermined frames. Digital video signals of at least one frame are intraframe coded and then transmitted. Remaining digital video signals are interframe coded with reference to the intraframe coded digital video signals, and intraframe coded digital video signals of a subsequent group of frames and are then transmitted. A motion vector from a predetermined reference frame is detected. Video signals are interframe coded by the motion vector to transmit the video signals. A motion vector from a first frame which is a plurality of frames away from the reference frame is converted to a motion vector for a one frame interval between the reference frame and the first frame. The motion vector is optimized, and is then transmitted.