Patent ID: 6839386
Filing Date: 2005-01-04
Classification: H04N

Abstract:
1. A picture decoding apparatus for decoding the moving picture information of a second resolution from the compressed picture information of a first resolution obtained on predictive encoding in terms of a pre-set pixel or macroblock block as a unit and on orthogonal transform in terms of a pre-set pixel block or as a unit, said second resolution being lower than said first resolution, said picture decoding apparatus comprising: inverse orthogonal transform means for inverse orthogonal transforming each coefficient of the orthogonal transform block of orthogonal transformed compressed picture information; addition means for summing the transformed compressed picture information obtained on inverse orthogonal transform by said inverse orthogonal transform means to motion compensated reference picture information to output said moving picture information of the second resolution; storage means for memorizing the moving picture information output by said addition means as reference picture information; first motion compensation means for motion compensating the macroblock of the reference picture information motion-predicted in accordance with a motion prediction system associated with interlaced scanning; and second motion compensation means for motion compensating the macroblock of the reference picture information motion-predicted in accordance with a motion prediction system associated with sequential scanning; said inverse orthogonal transform means inverse orthogonal transforming four coefficients of a low range in the horizontal direction and eight coefficients in the vertical direction in respective coefficients in an orthogonal transform block of the compressed picture information, and further comprises a 4×8 matrix composed of a transposed order four IDCT matrix and a 4×4 zero-matrix for executing a discrete cosine transform in the horizontal direction and an 8×8 matrix composed of an order eight inverse DCT matrix for executing a discrete cosine transform in the vertical direction.