Abstract: A digital video signal reproducing apparatus is arranged such that when a low frequency component of a reproduced signal is extracted, the reproduced signal forms a reproduced image plane. When a low frequency component of a reproduced signal is extracted but a high frequency component thereof is not extracted, the low frequency component thus extracted is compared with a low frequency component of a previously or subsequently reproduced signal. If the two low frequency components are substantially equal to each other, the reproduced signal is concealed to form a reproduced image plane, and if not substantially equal to each other, the reproduced signal forms a reproduced image plane without being concealed.

Abstract: In an orthogonal transfrom coding apparatus for performing high efficiecy coding using orthogonal transformation, a plurality of quantizers are provided; the coded amount of data of the plurality of quantizers are respectively calculated; an optimum quantizer to make the amount of data less than a specific value is selected to quantize the coded amount of data, and the quantized values are encoded in a variable-length form and the transmitted.

Abstract: A decimation or interpolation filter is selectively used for decimation or interpolation of pixel data of a chrominance component of a video signal, In general, the chrominance signal and the luminance signal are closely related to each other and their edge pattern data coincide with each other when reproduced on a picture screen. A filter device for decimation or interpolation of the chrominance signal is arranged to perform a number of filtering actions depending on the presence or absence and location of edge pattern data. The present, absence, and location of the edge pattern data is detected using a luminance signal which is neither decimated nor interpolated.

Abstract: In an orthogonal transform coding apparatus for performing high efficiency coding using orthogonal transformation, a plurality of quantizers are provided; the coded amount of data of the plurality of quantizers are respectively calculated; an optimum quantizer to make the amount of data less than a specific value is selected to quantize the coded amount of data, and the quantized values are encoded in a variable-length form and .[.the.]. .Iadd.then .Iaddend.transmitted.