Patent ID: 6256343
Filing Date: 2001-07-03
Classification: H04N

Abstract:
A video coding method of obtaining a local motion vector block by block using a block of a first kind obtained by dividing an input picture of a current frame into a plurality of blocks and a reference picture of a previous frame, quantizing transform coefficients derived by orthogonal transforming a predictive error signal between a prediction picture obtained by performing motion compensation using the reference picture and a picture of the block image of the first kind by using a quantizing parameter which is set to be smaller as the average value of a quantizing step width is narrowed, and coding the motion vector and the quantized transform coefficients,in a step of obtaining the local motion vector of the block of the first kind by a first block matching process performed between the reference picture with blocks corresponding to a plurality of candidate local motion vectors and the block of the first kind,in the case where a value obtained by subtracting a first integer from the sum of absolute-value or the sum of square-value of predictive error signals in the block is used as an evaluation value when the candidate motion vector is zero, the evaluation values for the plurality of candidate motion vectors are compared, and a candidate motion vector for which the evaluation value is the minimum is used as a local motion vector of the block,a plurality of values are used as the first integer in accordance with the value of the quantizing parameter, the first integer is controlled by the quantizing parameter in such a manner that two values as the first integer for two different quantizing parameters are set so that the value of the first integer corresponding to the smaller quantizing parameter is smaller than or equal to the value of the first integer corresponding to the larger quantizing parameter.