Abstract: A magnetic recording and/or reproducing apparatus in which the decoding error rate is to be lowered through realization of the high-performance encoding and the high efficiently decoding. To this end, a magnetic recording and/or reproducing apparatus 50 includes, in its recording system, an error correction coder 51 for error correction encoding input data, an interleaver 52 for interleaving data supplied from the error correction coder 51 for re-arraying the data sequence, a modulation encoder 53 for modulation encoding the data from the interleaver 52 in a predetermined fashion and an interleaver 54 for interleaving the data from the modulation encoder 53 for re-arraying the data sequence.

Abstract: A magnetic recording and/or reproducing apparatus which achieves high performance encoding and high efficiency decoding to lower the decoding error rate. A magnetic recording and/or reproducing apparatus 50 includes, in its recording system, an error correction coder 51 for error correction coding input data and an interleaver 52 for scrambling the sequence of data supplied from the error correction coder 51.

Abstract: A magnetic recording and/or reproducing apparatus performing efficient decoding to lower a decoding error rate. A magnetic recording and/or reproducing apparatus 50 includes a modulation SISO decoder 63 for modulation decoding data modulation-encoded in a predetermined fashion by a modulation coder 52. In the magnetic recording and/or reproducing apparatus 50, the modulation SISO decoder 63 is a soft input soft output (SISO) type modulation decoder fed with a soft input signal and issuing a soft output signal. The modulation SISO decoder 63 is fed with a trellis soft output signal D64 supplied from a trellis SISO decoder 62 to find a soft decision value for an error correction coding data D52 fed to the modulation coder 52 of the recording system to generate a modulated soft decision signal D65. The modulation SISO decoder 63 routes the so-generated modulated soft decision signal D65 to a downstream side error correction soft decoder 64.

Abstract: To carry out error correction coding and decoding according to a serially concatenated coded modulation system with a small circuit scale and high performance. A coding apparatus 1 is designed so that an interleaver 20 interleaves order of bits so that all weights are coded by a convolutional coder 30 with respect to data comprising a series of 3 bits supplied from a convolutional coder 10; the convolutional coder 30 makes as small as possible the total value of the hamming distance of input bit between passes to be the minimum Euclidean distance with respect to data of 3 bits supplied from the interleaver 20; and a multi-value modulation mapping circuit 40 causes the hamming distance of input bits in the convolutional coder 30 as the distance between signal point on the I/Q plane is smaller to subject data of 3 bits supplied from the convolutional coder 30 to mapping.

Abstract: Error correction coding and decoding according to a serial concatenated modulation system are carried out under high code rate. A coding apparatus 1 comprises three convolutional coders 10, 30 and 50 for carrying out convolutional operation; two interleavers 20 and 40 for rearranging order of data input; and a multi-value mapping circuit 60 for carrying out mapping of a single point on the basis of a predetermined modulation system. The coding apparatus 1 carries out convolutional operation whose code rate is “⅔” as coding of extrinsic codes by a convolutional coder 10, and carries out convolutional operation whose code rate is “1” as coding of inner codes by a convolutional coder 50, and a multi-value modulation mapping circuit 60 applies mapping to a transmission symbol of a 8 PSK modulation system to output it as a single code transmission symbol.

Abstract: Branch metric is calculated by a branch metric calculating circuit 21 on the basis of an input signal. ACS processing to select path of high likelihood on the basis of the branch metric to output state metric is carried out by an ACS circuit 22. Select information obtained by this ACS processing is stored into a path memory circuit 25. Normalization processing of all state metrics are carried out by a normalization circuit 23 on the basis of whether or not only one state metric outputted by the ACS processing is a set value determined in advance. The normalized state metrics are stored into a state metric memory circuit 24. Maximum likelihood decoding judgment processing for selecting maximum likelihood path is carried out by a maximum likelihood decoding judgment circuit 26 on the basis of select information stored in the path memory circuit 25.

Abstract: The feature points of the input video signal are detected by canny edge detecting method, the coordinates of the feature points detected are chain coded, the length of the region, including the feature points, of which edge intensity is the specified value or more in the edge intensity maximum change direction at the feature point coordinates obtained when the feature point is detected, are code, and the chain-coded data and the region length coded data are then multiplexed. Thereby, the amount of bits required for coding of the coordinates information can be reduced, as a result the total amount of codes can be reduced.

Abstract: A device for encoding turbo codes for use in satellite communications. Input data including termination bits are supplied to a series of interleaver circuits. Coding circuits perform convolution operations on data output from the respective interleavers, thereby obtaining coded data. The encoding process automatically results in terminated coded data. Thus, termination circuits are unnecessary. The determination of substitute positions by the respective interleavers through arithmetic computations makes it unnecessary to provide separate memory to store substitute position information.

Abstract: In a picture encoding and decoding method and apparatus, an object contour can be chain coded precisely even in the case where noise exists in the vicinity of object contour, and the object contour branched off can be coded with small quantity of codes. In the case where the branched part occurs in a feature point chain, by multiplexing branch code D1 to chain codes S23 and S22 and expressing as a tree structured feature point chain including the branch part of the object contour, an increase in number of chains can be controlled and the efficient chain coding can be conducted. Moreover, since the terminal branch chains having no branch point in the chain become the objects of thresholding, only noise elements can be effectively eliminated without cutting off the feature point chain showing the object contours.

Abstract: An image encoding method for encoding moving images, comprising the steps of:detecting characteristic points of a moving image;encoding a chain generated based on information relating to the characteristic points in such a manner as to generate chain encoded data, with the chain corresponding to an outline of the image;detecting motion of the chain and generating information corresponding to the motion; andmultiplexing the chain encoded data and the motion information.

Abstract: In an image signal coding and decoding method in which feature points in an image signal are detected and information concerned with sets of continuous feature points is chain-coded, the quantity of information is reduced without deterioration of image quality. An image signal coding and decoding method in which components of a direction displacement between the direction of transition from a feature point two feature points before a current feature point to a preceding feature point and the direction of transition from the preceding feature point to the current feature point are detected and subjected to entropy coding.

Abstract: The feature points of the input video signal are detected by canny edge detecting method, the coordinates of the feature points detected are detected is chain coded, the length of the region, including the feature points, of which edge intensity is the specified value or more in the edge intensity maximum change direction at the feature point coordinates obtained when the feature point is detected, are coded. The chain-coded data and the region length coded data are then multiplexed. Thereby, the amount of bits required for coding of the coordinates information can be reduced, as a result the total amount of codes can be reduced.

Abstract: In a picture encoding and decoding method and apparatus, an object contour can be chain coded precisely even in the case where noise exists in the vicinity of object contour, and the object contour branched off can be coded with small quantity of codes. In the case where the branched part occurs in a feature point chain, by multiplexing branch code D1 to chain codes S23 and S22 and expressing as a tree structured feature point chain including the branch part of the object contour, an increase in number of chains can be controlled and the efficient chain coding can be conducted. Moreover, since the terminal branch chains having no branch point in the chain become the objects of thresholding, only noise elements can be effectively eliminated without cutting off the feature point chain showing the object contours.