/*
* compute cornerness
*/
bool harrisCorners::getCornerness(const channel& fxx,
const channel& fxy,
const channel& fyy,
const float scale,
channel& cornerness,
float& maxCornerness) const {
// we can assume that all channels are connected, but try it out if not
if ((fxx.getMode() != channel::Connected) ||
(fxy.getMode() != channel::Connected) ||
(fyy.getMode() != channel::Connected)) {
setStatusString("Channels not contigous in getCornerness");
return false;
}
if (fxx.empty() || fxy.empty() || fyy.empty()) {
cornerness.clear();
maxCornerness = 0.0f;
return false;
}
int i;
const int end = fxx.rows()*fxx.columns();
const float *const pfxx = &fxx.at(0);
const float *const pfxy = &fxy.at(0);
const float *const pfyy = &fyy.at(0);
cornerness.resize(fxx.size(),0,false,false);
float* pcor = &cornerness.at(0);
float det,trace,txx,txy,tyy,c;
float maxc = 0.0f;
for (i=0;i<end;++i) {
txx=pfxx[i];
txy=pfxy[i];
tyy=pfyy[i];
det=txx*tyy - txy*txy;
trace=txx+tyy;
c = det-scale*trace*trace;
pcor[i]=c;
if (c>maxc) {
maxc=c;
}
}
maxCornerness = maxc;
return true;
}
bool hessianFunctor::classicXY(const channel& src, channel& xy) const {
if (src.columns() < 3) {
setStatusString("width less than 3");
xy.clear();
return false;
}
if (src.rows() < 3) {
setStatusString("height less than 3");
xy.clear();
return false;
}
if (src.getMode()!=channel::Connected) {
setStatusString("src must be Connected");
xy.clear();
return false;
}
const int width = src.columns();
const int height = src.rows();
xy.resize(height,width,0.f,false,false);
float* fpxy = &xy.at(0,0);
const float* fpSrc = &src.at(0,0);
const float* rowy;
const float* colx;
float* pidxy;
const int w1 = width-1;
const int w2 = width-2;
const int last = (height-1)*width; // index of begin of last row
const int lastRow = -w1; // offset from actual column pointer to
// last row
const int nextRow = width+1; // offset from actual column pointer to
// next row
const int nextRow2 = width+2; // offset from actual column pointer to
// next row + 1
// top-left corner
fpxy[0]=(fpSrc[0]-fpSrc[1]-fpSrc[width]+fpSrc[nextRow]);
// top
pidxy = &fpxy[1];
for (colx=&fpSrc[0],rowy=&fpSrc[w1];
colx<rowy;
++colx,++pidxy) {
*pidxy=(*colx - colx[2] - colx[width] + colx[nextRow2]);
}
// top-right corner
fpxy[w1]=(fpSrc[w2]-fpSrc[w1]-fpSrc[w2+width]+fpSrc[w1+width]);
// main loop (begin at coordinates (1,0)
pidxy = &fpxy[width];
const float *const rowEnd = &fpSrc[last];
for (rowy=&fpSrc[width];
rowy<rowEnd;
rowy+=width) {
// left side
*pidxy=(rowy[-width] - rowy[lastRow] - rowy[width] + rowy[nextRow]);
++pidxy;
// middle
const float *const colEnd = &rowy[w2];
for (colx=rowy;
colx<colEnd;
++colx,++pidxy) {
*pidxy=(colx[-width] - colx[-w2] - colx[width] + colx[nextRow2]);
}
// right side
*pidxy=(colx[-width] - colx[lastRow] - colx[width] + colx[nextRow]);
++pidxy;
}
// bottom-left corner
fpxy[last]=(fpSrc[last+1]-fpSrc[last]);
// bottom
pidxy = &fpxy[last+1];
const float *const colEnd = &rowEnd[w2];
for (colx=rowEnd;
colx<colEnd;
++colx,++pidxy) {
*pidxy=(colx[-width] - colx[-w2] - *colx + colx[2]);
}
// bottom-right corner
fpxy[last+w1]=(fpSrc[last-2]-fpSrc[last-1]-fpSrc[last+w2]+fpSrc[last+w1]);
return true;
};
