Patent ID: 8237805
Filing Date: 2012-08-07
Classification: G06T

Abstract:
1. An image processing device comprising: an image receiving section that receives a first photographic image and a second photographic image of a same examination object, the first and second photographic images being imaged at imaging times different from each other; a time difference acquiring section that acquires a time difference between the imaging times of the first and second photographic images; a processing section that (a) determines a plurality of reference image portions in the first photographic image each of which is composed of a same number of pixels and has a same predetermined shape, (b) determines a plurality of search ranges in the second photographic image each of which is composed of more than the same number of pixels, and which have respectively centers at a plurality of positions in the second photographic image corresponding to positions of centers of the same predetermined shapes of the plurality of reference image portions respectively, (c) obtains two or more comparison image portions in each of the plurality of search ranges each comparison image portion of which is composed of a same number of pixels as the same number of pixels in each of the plurality of reference image portions and has the same predetermined shape, (d) obtains a sum of differences between pixel values of pixels in each of the two or more comparison image portions in the each of the plurality of search ranges, and pixel values of pixels in one of the plurality of reference image portions that has a center at a position in the first photographic image corresponding to a position of a center of the each of the plurality of search ranges, (e) determines, as a matching image portion, one of the two or more comparison image portions which has the smallest sum of differences of the two or more comparison image portions, (f) obtains a vector which connects a center of the matching image portion and the center of the each of the plurality of search ranges, and (g) performs a matching processing on the second photographic image to match the second photographic image with the first photographic image by locally deforming the second photographic image by amounts of local deformation along local deformation directions each of which is calculated by using the obtained vector as a first approximation to the each of the amounts of local deformation along the local deformation directions; and a parameter setting section that sets, to the processing section as the same number which represent a number of pixels composing each of the plurality of reference image portions, a number that is varied in accordance with the time difference in such a manner that the larger the time difference is, the smaller the number is.