1IM_SGLDS_MATRIX(3)         Library Functions Manual         IM_SGLDS_MATRIX(3)
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NAME

6       im_glds_matrix,     im_glds_asm,     im_glds_contrast,    im_glds_mean,
7       im_glds_entropy - calculate the spatial grey  level  difference  matrix
8       and features on it
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SYNOPSIS

11       #include <vips/vips.h>
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13       int im_glds_matrix(im, m, xp, yp, xs, ys, dx, dy)
14       IMAGE *im, *m;
15       int xp, yp, xs, ys;
16       int dx, dy;
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18       int im_glds_asm(m, asmoment)
19       IMAGE *m;
20       double *asmoment;
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22       int im_glds_contrast(m, contrast)
23       IMAGE *m;
24       double *contrast;
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26       int im_glds_entropy(m, entropy)
27       IMAGE *m;
28       double *entropy;
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30       int im_glds_mean(m, mean)
31       IMAGE *m;
32       double *mean;
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DESCRIPTION

36       im_glds_matrix() creates a 256 by 1 one channel spatial grey level dif‐
37       ference matrix (sglds) of the box determined by the parameters (xp, yp;
38       xs,  ys)  within  the  image  pointed  by the IMAGE descriptor im.  The
39       matrix is written onto the IMAGE descriptor m.  The displacement vector
40       is  determined  by (dx, dy).  The user must ensure that there is enough
41       border pixels around the box within im  dictated  by  the  displacement
42       vector  (dx,dy)  or  else  the  program  fails.  im  should be one-band
43       unsigned char.
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45       All entries of the sgld matrix are double normalised to the  number  of
46       pairs involved.  This function is a direct implementation of the paper:
47       Haralick R.  M., Shanmugan K. and Dinstein I., 'Textural  features  for
48       image classification', IEEE Transactions on Systems, Man, and Cybernet‐
49       ics, Vol.  SMC-3, No 6, Nov. 1973, pp 610-621.
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51       im_glds_asm() calculates the angular second moment of the co-occurrence
52       matrix  held by m.  The result is returned into the location pointed by
53       asmoment.
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55       im_glds_contrast() calculates the contrast of the sglds matrix held  by
56       m.  The result is returned into the location pointed by contrast.
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58       im_glds_entropy() calculates the entropy of the sglds matrix held by m.
59       The result is returned into the location pointed by entropy.
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61       im_glds_mean() calculates the mean of the sglds matrix held by m.   The
62       result is returned into the location pointed by mean.
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RETURNED VALUES

65       All functions returns 0 on success and -1 on error.
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SEE ALSO

68       im_cooc_matrix(3)
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71       N. Dessipris
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AUTHOR

74       N. Dessipris - 10/05/1991
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78                                  10 May 1991               IM_SGLDS_MATRIX(3)
Impressum