1IM_DIF_STD(3) Library Functions Manual IM_DIF_STD(3)
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6 im_dif_std - calculate the mean and the standard deviation of the dif‐
7 ference image for a given displacement vector
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10 #include <vips/vips.h>
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12 int im_dif_std(im, xp, yp, xs, ys, dx, dy, mean, std)
13 IMAGE *im;
14 int xp, yp, xs, ys;
15 int dx, dy;
16 double *mean, *std;
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20 im_dif_std() calculates the mean and the standard deviation of the dif‐
21 ference image created by the displacement vector (dx,dy) on the box
22 (xp,yp;xs,ys) defined on the image pointed by im. More specifically
23 the difference image is of an image given the dispacement vector (dx,
24 dy) is defined as follows: For each point of the original image, the
25 start of the vector (dx,dy) is set on that point. The difference image
26 at this point is defined as the difference of the values pointed by the
27 vector (end value - start value). The function returns the mean and
28 the standard deviation of the difference images measured on the area
29 (xp,yp;xs,ys) of im.
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31 Input im should be one band unsigned char image and it should have been
32 set by a call to im_mmapin(3) or im_setbuf(3).
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36 The function returns 0 on success and -1 on error.
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39 im_cooc_matrix(3), im_glds_matrix(3)
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42 N. Dessipris
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45 N. Dessipris - 10/05/1991
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49 10 May 1991 IM_DIF_STD(3)