Abstract: A signal recording apparatus includes a quantizer for quantizing a signal employing a quantization step. The apparatus further includes a quantization information creator for creating plural pieces of quantization information to specify the quantization step, an encoder for generating an encoded signal from the quantized signal, and a recorder for recording a compressed signal having data containing the plural pieces of quantization information and the encoded signal.

Abstract: An image signal encoding device has at least encoding means of dividing a luminescence signal and color-difference signals of image signals into macro blocks having a plurality of sub macro blocks and encoding data of the macro blocks with use of any one of a plurality of compression modes of which compression rate is different each other, wherein the total numbers of sub macro blocks in the each macro block are the same for the use of the all kinds of compression modes.

Abstract: A video signal shuffling device forms a segment with blocks having a given offset value in horizontal and vertical directions from a given starting point uniquely determined on the screen, the offset value being identical in every region. The segment is formed in a unit of one frame or two frames. The shuffling device divides one frame comprising blocks into a plurality of regions. A coding device determines a final priority as well as a final quantizer thereby quantizing a segment and providing the segment with a variable-length-coding based on a first priority, coding-quantity obtained from a plurality of quantizers, second priority and a quantizer. A coding device and its decoder, the coding device carries out a hierarchical coding by only a motion vector in a compressed stream at a lower resolution side and by agreeing a motion detected and a DCT block size with a size on the screen.

Abstract: It was impossible to easily carry recorded images and sound by using a low-capacity memory medium and to receive them in the open air.

Abstract: When recording/reproducing a digital video signal having 1080 effective lines, an MPEG stream can be extracted on the reproducing side with a simple structure and without causing serious deterioration of the image quality, and without wastefully consuming the capacity of the recording medium. To achieve this object, a macro block assembling circuit (semi-MPEG) 20 in the compression circuit 10 assembles macro blocks having 16 lines and macro blocks having 8 lines from the digital video signal. A DCT circuit (MPEG) 22 applies field DCT or frame DCT defined by the MPEG standard to the macro blocks with 16 lines and applies only the frame DCT defined by the MPEG standard to the macro blocks with 8 lines.

Abstract: An image signal encoding device has at least encoding means of dividing a luminescence signal and color-difference signals of image signals into macro blocks having a plurality of sub macro blocks and encoding data of the macro blocks with use of any one of a plurality of compression modes of which compression rate is different each other,

Abstract: A signal recording apparatus, has

Abstract: In a recording and reproducing apparatus with image coding for compression coding of digital video signals and for recording and reproducing the compressed code, digital video signals are divided on a screen into coding blocks which are overlapped so as to share boundary pixels. DCT coefficient data in each coding block are divided into a plurality of groups, and coefficient data in two coding blocks overlapping on the screen are recorded to separate regions on a recording medium. When an error has occurred during a reproducing process, the state of the error occurrence is analyzed and an error correction responsive to the state of error occurrence is performed on coefficient data that has been lost due to the error. Thus, a stable, successful reproduced image can be obtained even if an error occurs during the recording and reproducing process.

Abstract: A coding apparatus for image compression which includes a transformer that transforms image data into a plurality of transform coefficients arranged in a matrix; a quantizer that quantizes each of the transform coefficients into a coefficient data of a predetermined number of bits; a data divider that divides the coefficient data into a fixed-length data part and a variable-length data part and a variable-length encoder that encodes the variable-length data part into a variable-length code.

Abstract: Coefficient data in two coding blocks which overlap on a video screen are recorded in distant regions on a recording medium, the distant regions not being directly adjacent to one another. Error detected coefficient data during reproduction are corrected with reference to the feature that the overlapped pixels between the two coding blocks are equal.

Abstract: An image compression-coding device includes a level conversion circuit for adaptively reducing the amplitude of the quantification coefficient data based on statistical characteristics of the quantification coefficient data. The device further includes a selection circuit for selectively outputting either the quantification coefficient data after the level conversion or the quantification coefficient data before the level conversion, so that the image compression-coding device outputs a smaller amount of variable-length codes.