mlib_ImageGradientMxN(3MLIB) mediaLib Library Functions mlib_ImageGradientMxN(3MLIB)
NAME
mlib_ImageGradientMxN - MxN gradient filter
SYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>
mlib_status mlib_ImageGradientMxN(mlib_image *dst, const mlib_image *src,
const mlib_d64 *hmask, const mlib_d64 *vmask, mlib_s32 m, mlib_s32 n,
mlib_s32 dm, mlib_s32 dn, mlib_s32 cmask, mlib_edge edge);
DESCRIPTION
The mlib_ImageGradientMxN() function performs edge detection by computing the magnitude of the image gradient vector in two orthogonal
directions using MxN gradient filtering.
It uses the following equation:
dst[x][y][i] = ( SH(x,y,i)**2 + SV(x,y,i)**2 )**0.5
where SH() and SV() are the horizontal and vertical gradient images generated from the corresponding channel of the source image by corre-
lating it with the supplied orthogonal (horizontal and vertical) gradient masks.
PARAMETERS
The function takes the following arguments:
dst Pointer to destination image.
src Pointer to source image.
hmask Pointer to horizontal mask in row-major order.
vmask Pointer to vertical mask in row-major order.
m Width of the convolution kernel. m > 1.
n Height of the convolution kernel. n > 1.
dm X coordinate of the key element in the convolution kernel. 0 <= dm < m.
dn Y coordinate of the key element in the convolution kernel. 0 <= dn < n.
cmask Channel mask to indicate the channels to be convolved, each bit of which represents a channel in the image. The channels corre-
sponding to 1 bits are those to be processed. For a single channel image, the channel mask is ignored.
edge Type of edge condition. It can be one of the following:
MLIB_EDGE_DST_NO_WRITE
MLIB_EDGE_DS_FILL_ZERO
MLIB_EDGE_DST_COPY_SRC
MLIB_EDGE_SR_EXTEND
RETURN VALUES
The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
mlib_ImageGradientMxN_Fp(3MLIB), mlib_ImageGradient3x3(3MLIB), mlib_ImageGradient3x3_Fp(3MLIB), attributes(5)
SunOS 5.11 2 Mar 2007 mlib_ImageGradientMxN(3MLIB)