opencv/modules/imgproc/src/canny.cpp
2013-10-05 14:54:00 +04:00

339 lines
11 KiB
C++

/*M///////////////////////////////////////////////////////////////////////////////////////
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#include "precomp.hpp"
#if defined (HAVE_IPP) && (IPP_VERSION_MAJOR >= 7)
#define USE_IPP_CANNY 1
#else
#undef USE_IPP_CANNY
#endif
#ifdef USE_IPP_CANNY
namespace cv
{
static bool ippCanny(const Mat& _src, Mat& _dst, float low, float high)
{
int size = 0, size1 = 0;
IppiSize roi = { _src.cols, _src.rows };
ippiFilterSobelNegVertGetBufferSize_8u16s_C1R(roi, ippMskSize3x3, &size);
ippiFilterSobelHorizGetBufferSize_8u16s_C1R(roi, ippMskSize3x3, &size1);
size = std::max(size, size1);
ippiCannyGetSize(roi, &size1);
size = std::max(size, size1);
AutoBuffer<uchar> buf(size + 64);
uchar* buffer = alignPtr((uchar*)buf, 32);
Mat _dx(_src.rows, _src.cols, CV_16S);
if( ippiFilterSobelNegVertBorder_8u16s_C1R(_src.data, (int)_src.step,
_dx.ptr<short>(), (int)_dx.step, roi,
ippMskSize3x3, ippBorderRepl, 0, buffer) < 0 )
return false;
Mat _dy(_src.rows, _src.cols, CV_16S);
if( ippiFilterSobelHorizBorder_8u16s_C1R(_src.data, (int)_src.step,
_dy.ptr<short>(), (int)_dy.step, roi,
ippMskSize3x3, ippBorderRepl, 0, buffer) < 0 )
return false;
if( ippiCanny_16s8u_C1R(_dx.ptr<short>(), (int)_dx.step,
_dy.ptr<short>(), (int)_dy.step,
_dst.data, (int)_dst.step, roi, low, high, buffer) < 0 )
return false;
return true;
}
}
#endif
void cv::Canny( InputArray _src, OutputArray _dst,
double low_thresh, double high_thresh,
int aperture_size, bool L2gradient )
{
Mat src = _src.getMat();
CV_Assert( src.depth() == CV_8U );
_dst.create(src.size(), CV_8U);
Mat dst = _dst.getMat();
if (!L2gradient && (aperture_size & CV_CANNY_L2_GRADIENT) == CV_CANNY_L2_GRADIENT)
{
//backward compatibility
aperture_size &= ~CV_CANNY_L2_GRADIENT;
L2gradient = true;
}
if ((aperture_size & 1) == 0 || (aperture_size != -1 && (aperture_size < 3 || aperture_size > 7)))
CV_Error(CV_StsBadFlag, "");
if (low_thresh > high_thresh)
std::swap(low_thresh, high_thresh);
#ifdef HAVE_TEGRA_OPTIMIZATION
if (tegra::canny(src, dst, low_thresh, high_thresh, aperture_size, L2gradient))
return;
#endif
#ifdef USE_IPP_CANNY
if( aperture_size == 3 && !L2gradient &&
ippCanny(src, dst, (float)low_thresh, (float)high_thresh) )
return;
#endif
const int cn = src.channels();
Mat dx(src.rows, src.cols, CV_16SC(cn));
Mat dy(src.rows, src.cols, CV_16SC(cn));
Sobel(src, dx, CV_16S, 1, 0, aperture_size, 1, 0, cv::BORDER_REPLICATE);
Sobel(src, dy, CV_16S, 0, 1, aperture_size, 1, 0, cv::BORDER_REPLICATE);
if (L2gradient)
{
low_thresh = std::min(32767.0, low_thresh);
high_thresh = std::min(32767.0, high_thresh);
if (low_thresh > 0) low_thresh *= low_thresh;
if (high_thresh > 0) high_thresh *= high_thresh;
}
int low = cvFloor(low_thresh);
int high = cvFloor(high_thresh);
ptrdiff_t mapstep = src.cols + 2;
AutoBuffer<uchar> buffer((src.cols+2)*(src.rows+2) + cn * mapstep * 3 * sizeof(int));
int* mag_buf[3];
mag_buf[0] = (int*)(uchar*)buffer;
mag_buf[1] = mag_buf[0] + mapstep*cn;
mag_buf[2] = mag_buf[1] + mapstep*cn;
memset(mag_buf[0], 0, /* cn* */mapstep*sizeof(int));
uchar* map = (uchar*)(mag_buf[2] + mapstep*cn);
memset(map, 1, mapstep);
memset(map + mapstep*(src.rows + 1), 1, mapstep);
int maxsize = std::max(1 << 10, src.cols * src.rows / 10);
std::vector<uchar*> stack(maxsize);
uchar **stack_top = &stack[0];
uchar **stack_bottom = &stack[0];
/* sector numbers
(Top-Left Origin)
1 2 3
* * *
* * *
0*******0
* * *
* * *
3 2 1
*/
#define CANNY_PUSH(d) *(d) = uchar(2), *stack_top++ = (d)
#define CANNY_POP(d) (d) = *--stack_top
// calculate magnitude and angle of gradient, perform non-maxima supression.
// fill the map with one of the following values:
// 0 - the pixel might belong to an edge
// 1 - the pixel can not belong to an edge
// 2 - the pixel does belong to an edge
for (int i = 0; i <= src.rows; i++)
{
int* _norm = mag_buf[(i > 0) + 1] + 1;
if (i < src.rows)
{
short* _dx = dx.ptr<short>(i);
short* _dy = dy.ptr<short>(i);
if (!L2gradient)
{
for (int j = 0; j < src.cols*cn; j++)
_norm[j] = std::abs(int(_dx[j])) + std::abs(int(_dy[j]));
}
else
{
for (int j = 0; j < src.cols*cn; j++)
_norm[j] = int(_dx[j])*_dx[j] + int(_dy[j])*_dy[j];
}
if (cn > 1)
{
for(int j = 0, jn = 0; j < src.cols; ++j, jn += cn)
{
int maxIdx = jn;
for(int k = 1; k < cn; ++k)
if(_norm[jn + k] > _norm[maxIdx]) maxIdx = jn + k;
_norm[j] = _norm[maxIdx];
_dx[j] = _dx[maxIdx];
_dy[j] = _dy[maxIdx];
}
}
_norm[-1] = _norm[src.cols] = 0;
}
else
memset(_norm-1, 0, /* cn* */mapstep*sizeof(int));
// at the very beginning we do not have a complete ring
// buffer of 3 magnitude rows for non-maxima suppression
if (i == 0)
continue;
uchar* _map = map + mapstep*i + 1;
_map[-1] = _map[src.cols] = 1;
int* _mag = mag_buf[1] + 1; // take the central row
ptrdiff_t magstep1 = mag_buf[2] - mag_buf[1];
ptrdiff_t magstep2 = mag_buf[0] - mag_buf[1];
const short* _x = dx.ptr<short>(i-1);
const short* _y = dy.ptr<short>(i-1);
if ((stack_top - stack_bottom) + src.cols > maxsize)
{
int sz = (int)(stack_top - stack_bottom);
maxsize = maxsize * 3/2;
stack.resize(maxsize);
stack_bottom = &stack[0];
stack_top = stack_bottom + sz;
}
int prev_flag = 0;
for (int j = 0; j < src.cols; j++)
{
#define CANNY_SHIFT 15
const int TG22 = (int)(0.4142135623730950488016887242097*(1<<CANNY_SHIFT) + 0.5);
int m = _mag[j];
if (m > low)
{
int xs = _x[j];
int ys = _y[j];
int x = std::abs(xs);
int y = std::abs(ys) << CANNY_SHIFT;
int tg22x = x * TG22;
if (y < tg22x)
{
if (m > _mag[j-1] && m >= _mag[j+1]) goto __ocv_canny_push;
}
else
{
int tg67x = tg22x + (x << (CANNY_SHIFT+1));
if (y > tg67x)
{
if (m > _mag[j+magstep2] && m >= _mag[j+magstep1]) goto __ocv_canny_push;
}
else
{
int s = (xs ^ ys) < 0 ? -1 : 1;
if (m > _mag[j+magstep2-s] && m > _mag[j+magstep1+s]) goto __ocv_canny_push;
}
}
}
prev_flag = 0;
_map[j] = uchar(1);
continue;
__ocv_canny_push:
if (!prev_flag && m > high && _map[j-mapstep] != 2)
{
CANNY_PUSH(_map + j);
prev_flag = 1;
}
else
_map[j] = 0;
}
// scroll the ring buffer
_mag = mag_buf[0];
mag_buf[0] = mag_buf[1];
mag_buf[1] = mag_buf[2];
mag_buf[2] = _mag;
}
// now track the edges (hysteresis thresholding)
while (stack_top > stack_bottom)
{
uchar* m;
if ((stack_top - stack_bottom) + 8 > maxsize)
{
int sz = (int)(stack_top - stack_bottom);
maxsize = maxsize * 3/2;
stack.resize(maxsize);
stack_bottom = &stack[0];
stack_top = stack_bottom + sz;
}
CANNY_POP(m);
if (!m[-1]) CANNY_PUSH(m - 1);
if (!m[1]) CANNY_PUSH(m + 1);
if (!m[-mapstep-1]) CANNY_PUSH(m - mapstep - 1);
if (!m[-mapstep]) CANNY_PUSH(m - mapstep);
if (!m[-mapstep+1]) CANNY_PUSH(m - mapstep + 1);
if (!m[mapstep-1]) CANNY_PUSH(m + mapstep - 1);
if (!m[mapstep]) CANNY_PUSH(m + mapstep);
if (!m[mapstep+1]) CANNY_PUSH(m + mapstep + 1);
}
// the final pass, form the final image
const uchar* pmap = map + mapstep + 1;
uchar* pdst = dst.ptr();
for (int i = 0; i < src.rows; i++, pmap += mapstep, pdst += dst.step)
{
for (int j = 0; j < src.cols; j++)
pdst[j] = (uchar)-(pmap[j] >> 1);
}
}
void cvCanny( const CvArr* image, CvArr* edges, double threshold1,
double threshold2, int aperture_size )
{
cv::Mat src = cv::cvarrToMat(image), dst = cv::cvarrToMat(edges);
CV_Assert( src.size == dst.size && src.depth() == CV_8U && dst.type() == CV_8U );
cv::Canny(src, dst, threshold1, threshold2, aperture_size & 255,
(aperture_size & CV_CANNY_L2_GRADIENT) != 0);
}
/* End of file. */