Patent ID: 6844830
Filing Date: 2005-01-18
Classification: H04N

Abstract:
1. A two-dimensional subband coding equipment which separates original data two-dimensionally arrayed in two directions, namely, in X and Y directions, into X- and Y-directional low- and high-frequency band component subbands, the equipment comprising: an X-directional subband transform means for calculating X-directional low-frequency band data that are X-directional low-frequency band components of the two-dimensionally arrayed original data and X-directional high-frequency band data that are X-directional high-frequency band components of the two-dimensionally arrayed original data to provide two-dimensionally arrayed X-directional low- and high-frequency band data; a Y-directional subband transform means for calculating X- and Y-directional low-frequency band data that are Y-directional low-frequency band components of the two-dimensionally arrayed X-directional low-frequency band data, X-directional low-frequency band and Y-directional high-frequency band data that are Y-directional high-frequency band components of the two-dimensionally arrayed X-directional low-frequency band data, X-directional high-frequency band and Y-directional low-frequency band data that are Y-directional low-frequency band components of the two-dimensionally arrayed high-frequency band data, and X- and Y-directional high-frequency band data that are Y-directional high-frequency band components of the two-dimensionally arrayed X-directional high-frequency band data to provide two-dimensionally arrayed X- and Y-directional low-frequency band data, X-directional low-frequency band and Y-directional high-frequency band data, X-directional high-frequency band and Y-directional low-frequency band data, and X- and Y-directional high-frequency band data; and a control means which controls data to be supplied to the X-directional subband transform means and Y-directional subband transform means; the X-directional subband transform means being supplied, for each transform, with a predetermined number of original data arrayed in the X direction in the two-dimensional array, and calculating one X-directional low-frequency band data and one X-directional high-frequency band data on the basis of the supplied predetermined number of X-directionally arrayed original data; the Y-directional subband transform means being supplied, for each transform, with a predetermined number of X-directional low- or high-frequency band data, arrayed in the Y direction in the two-dimensional array, and calculating one X- and Y-directional low-frequency band data and one X-directional low-frequency band and Y-directional high-frequency band data on the basis of the supplied predetermined number of Y-directionally arrayed X-directional low-frequency band data, and also one X-directional high-frequency band and Y-directional low-frequency band data and one X- and Y-directional high-frequency band data on the basis of the supplied predetermined number of Y-directionally arrayed X-directional high-frequency band data; the control means supplying the predetermined number of original data to the X-directional subband transform means in the Y-direction; and also, the control means supplying the predetermined number of Y-directionally arrayed X-directional low-frequency band data and predetermined number of Y-directionally arrayed X-directional high-frequency band data to the Y-directional subband transform means in the output sequence of the X-directional subband transform means, and also the X-directional low- and high-frequency band data alternately to the Y-directional subband transform means at each transform by the Y-directional subband transform means.