초록 ▼

The invention relates to an automatic image analysis method in which two images which have been recorded at different instants are analyzed and a transformation function is determined on the basis of the shifts of image sections, which transformation function describes the shift from one image to an

The invention relates to an automatic image analysis method in which two images which have been recorded at different instants are analyzed and a transformation function is determined on the basis of the shifts of image sections, which transformation function describes the shift from one image to another. In order to enable exact determination of this shift, corresponding image sections are determined in the two images by histogram analysis.

대표청구항 ▼

[ We claim:] [1.] An automatic image analysis method for analyzing a first image and a second image of the same object, the first and the second images comprising pixels having image values, the method comprising:defining a plurality of image sections (A.sub.1, A.sub.2, . . . A.sub.n) which subdivid

[ We claim:] [1.] An automatic image analysis method for analyzing a first image and a second image of the same object, the first and the second images comprising pixels having image values, the method comprising:defining a plurality of image sections (A.sub.1, A.sub.2, . . . A.sub.n) which subdivide an image region (F) to be processed in the first image,determining for each image section in the first image an optimum shift (v.sub.x, v.sub.y) from the first image to the second image, rein, for a particular image section, the optimum shift is selected to be that particular shift (v.sub.x, v.sub.y) for which a difference histogram associated with the particular image section and with the particular shift has the narrowest frequency maximum or maxima, the optimum shift being limited to be within a search area, and rein the difference histogram associated with a particular image section and with a particular shift is determined by (i) shifting the particular image section in the first image by the particular shift from its position in the first image to a shifted image section in the second image, (ii) forming a difference image section having pixels with difference image values determined by subtracting image values of first pixels in the particular image section from image values of corresponding second pixels in the shifted image section, a first pixel in the particular image section in the first image corresponding to a second pixel in the shifted image section in the second image if the positions of the two pixels differ by the particular shift, and (iii) forming the difference histogram as a histogram of the frequencies of the difference image values of pixels in the difference image section, anddetermining an affine transformation function (X, Y) from the first image to the second image approximating the optimum shifts (y.sub.x, v.sub.y) determined for the image sections.