US Patent 8160368 Image feature extraction method and image compression method

The image feature extraction method of the present invention includes: the step of performing k2 dividing process at least once on a given image so as to convert the given image into a multi-divided image, where the k2 dividing process comprises the steps of: a) creating matrix T based on image matrix X; b) computing singular values of the matrix T; c) determining whether or not minj|σj−σj−1|>ε; d) if the result of the determination in the step c) is “No”, returning to the step c) subsequent to computing the singular values of the enlarged matrix Tα; e) if the result of the determination in the step c) is “Yes”, obtaining U which satisfies T=USVT; f) obtaining matrix T1=UTT; and g) creating image matrix X1 based on matrix T1.