1mlib_ImageGradientMxN(3MLIBm)ediaLib Library Functionmslib_ImageGradientMxN(3MLIB)
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6 mlib_ImageGradientMxN - MxN gradient filter
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9 cc [ flag... ] file... -lmlib [ library... ]
10 #include <mlib.h>
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12 mlib_status mlib_ImageGradientMxN(mlib_image *dst, const mlib_image *src,
13 const mlib_d64 *hmask, const mlib_d64 *vmask, mlib_s32 m, mlib_s32 n,
14 mlib_s32 dm, mlib_s32 dn, mlib_s32 cmask, mlib_edge edge);
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18 The mlib_ImageGradientMxN() function performs edge detection by comput‐
19 ing the magnitude of the image gradient vector in two orthogonal direc‐
20 tions using MxN gradient filtering.
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23 It uses the following equation:
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25 dst[x][y][i] = ( SH(x,y,i)**2 + SV(x,y,i)**2 )**0.5
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29 where SH() and SV() are the horizontal and vertical gradient images
30 generated from the corresponding channel of the source image by corre‐
31 lating it with the supplied orthogonal (horizontal and vertical) gradi‐
32 ent masks.
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35 The function takes the following arguments:
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37 dst Pointer to destination image.
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40 src Pointer to source image.
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43 hmask Pointer to horizontal mask in row-major order.
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46 vmask Pointer to vertical mask in row-major order.
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49 m Width of the convolution kernel. m > 1.
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52 n Height of the convolution kernel. n > 1.
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55 dm X coordinate of the key element in the convolution kernel. 0 ≤
56 dm < m.
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59 dn Y coordinate of the key element in the convolution kernel. 0 ≤
60 dn < n.
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63 cmask Channel mask to indicate the channels to be convolved, each
64 bit of which represents a channel in the image. The channels
65 corresponding to 1 bits are those to be processed. For a sin‐
66 gle channel image, the channel mask is ignored.
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69 edge Type of edge condition. It can be one of the following:
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71 MLIB_EDGE_DST_NO_WRITE
72 MLIB_EDGE_DS_FILL_ZERO
73 MLIB_EDGE_DST_COPY_SRC
74 MLIB_EDGE_SR_EXTEND
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79 The function returns MLIB_SUCCESS if successful. Otherwise it returns
80 MLIB_FAILURE.
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83 See attributes(5) for descriptions of the following attributes:
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88 ┌─────────────────────────────┬─────────────────────────────┐
89 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
90 ├─────────────────────────────┼─────────────────────────────┤
91 │Interface Stability │Committed │
92 ├─────────────────────────────┼─────────────────────────────┤
93 │MT-Level │MT-Safe │
94 └─────────────────────────────┴─────────────────────────────┘
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97 mlib_ImageGradientMxN_Fp(3MLIB), mlib_ImageGradient3x3(3MLIB),
98 mlib_ImageGradient3x3_Fp(3MLIB), attributes(5)
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102SunOS 5.11 2 Mar 2007 mlib_ImageGradientMxN(3MLIB)