Image signal analysis

An image signal analyzing system accomplishes shape analysis for processing or coding an image, by space division using two orthogonal representative vectors, or by differential representative vectors given by the difference between representative vectors. With such a system, inner products between mean separated blocks produced by a mean separating unit and a differential representative vector set stored in a memory 9 are computed by inner product computing units 12, 12', 12" disposed in a binary tree shape having n stages. Positive/negative signs expressing the resulting inner products are held, as indexes, by n index holding means 14, 14', 14", and an index representing the shape of input image information is obtained from the n index holding means 14, 14', 14".