Patent ID: 7139315

Claim:
A motion picture decoding apparatus comprising: a coefficient reducing circuit for removing orthogonal transform coefficients for high horizontal frequencies from a certain sized block of orthogonal transform coefficients obtained from an input signal, thereby reducing the number of transform coefficients to half; an inverse orthogonal transformation circuit for performing an inverse orthogonal transform operation by using the transform coefficients reduced by the coefficient reducing circuit, thereby obtaining, on a block-by-block basis, first reconstructed image data or time-axis prediction error data horizontally compressed to ½; an adder for generating first reconstructed image data horizontally compressed to ½, based on the time-axis prediction error data provided by the inverse orthogonal transformation circuit and on predetermined reference image data; an Hadamard transformation coding circuit for quantizing, based on Hadamard transformation, the first reconstructed image data provided by the inverse orthogonal transformation circuit or the adder, thereby generating second reconstructed image data, the amount of which data is reduced bitwise to ½ from that of the first reconstructed image data; and one or more than one reference image memories for storing second reconstructed image data which is included in the second reconstructed image data provided by the Hadamard transformation coding circuit and is needed for generating the reference image data, the motion picture decoding apparatus wherein the second reconstructed image data stored in the reference image memory is used for generating the reference image data corresponding to the first reconstructed image data.