//! Calculate Haar wavelet responses in y direction
float haarY(int row, int column, int s)
{
return(COpenSURF.Area(img, column - s / 2, row, s, s / 2)
- 1 * COpenSURF.Area(img, column - s / 2, row - s / 2, s, s / 2));
}
void buildDet()
{
// Compute value for each position in the scale-space image.
int lobe, border, step;
float Dxx = 0, Dyy = 0, Dxy = 0, scale;
int ixdet = 0;
for (int o = 0; o < octaves; o++)
{
// calculate filter border for this octave
border = (3 * COpenSURF.cvRound(COpenSURF.pow(2.0f, o + 1) * (intervals) + 1) + 1) / 2;
step = init_sample * COpenSURF.cvRound(COpenSURF.pow(2.0f, o));
for (int i = 0; i < intervals; i++)
{
// calculate lobe length (filter side length/3)
lobe = COpenSURF.cvRound(COpenSURF.pow(2.0f, o + 1) * (i + 1) + 1);
scale = 1.0f / COpenSURF.pow((float)(3 * lobe), 2);
for (int r = border; r < i_height - border; r += step)
{
for (int c = border; c < i_width - border; c += step)
{
/***
* Dyy = COpenSURF.Area(img, c - (lobe - 1), r - ((3 * lobe - 1) / 2), (2 * lobe - 1), lobe)
* - 2 * COpenSURF.Area(img, c - (lobe - 1), r - ((lobe - 1) / 2), (2 * lobe - 1), lobe)
+ COpenSURF.Area(img, c - (lobe - 1), r + ((lobe + 1) / 2), (2 * lobe - 1), lobe);
+
+
+ Dxx = COpenSURF.Area(img, c - ((3 * lobe - 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1))
+ - 2 * COpenSURF.Area(img, c - ((lobe - 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1))
+ COpenSURF.Area(img, c + ((lobe + 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1));
+
+ Dxy = COpenSURF.Area(img, c - lobe, r - lobe, lobe, lobe)
+ COpenSURF.Area(img, c + 1, r + 1, lobe, lobe)
+ - COpenSURF.Area(img, c - lobe, r + 1, lobe, lobe)
+ - COpenSURF.Area(img, c + 1, r - lobe, lobe, lobe);
***/
{
float dyy0 = COpenSURF.Area(img, c - (lobe - 1), r - ((3 * lobe - 1) / 2), (2 * lobe - 1), lobe);
float dyy1 = COpenSURF.Area(img, c - (lobe - 1), r - ((lobe - 1) / 2), (2 * lobe - 1), lobe);
float dyy2 = COpenSURF.Area(img, c - (lobe - 1), r + ((lobe + 1) / 2), (2 * lobe - 1), lobe);
Dyy = dyy0 - 2 * dyy1 + dyy2;
}
{
float dxx0 = COpenSURF.Area(img, c - ((3 * lobe - 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1));
float dxx1 = COpenSURF.Area(img, c - ((lobe - 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1));
float dxx2 = COpenSURF.Area(img, c + ((lobe + 1) / 2), r - (lobe - 1), lobe, (2 * lobe - 1));
Dxx = dxx0 - 2 * dxx1 + dxx2;
}
{
float dxy0 = COpenSURF.Area(img, c - lobe, r - lobe, lobe, lobe);
float dxy1 = COpenSURF.Area(img, c + 1, r + 1, lobe, lobe);
float dxy2 = COpenSURF.Area(img, c - lobe, r + 1, lobe, lobe);
float dxy3 = COpenSURF.Area(img, c + 1, r - lobe, lobe, lobe);
Dxy = dxy0 + dxy1 - dxy2 - dxy3;
}
// Normalise the filter responses with respect to their size
Dxx *= scale;
Dyy *= scale;
Dxy *= scale;
// Get the sign of the laplacian
int lap_sign = (Dxx + Dyy >= 0 ? 1 : -1);
// Get the determinant of hessian response
float res = (Dxx * Dyy - 0.9f * 0.9f * Dxy * Dxy);
res = (res < thres ? 0 : lap_sign * res);
// calculate approximated determinant of hessian value
m_det[(o * intervals + i) * (i_width * i_height) + (r * i_width + c)] = res;
ixdet += 1;
if (res > 0)
{
}
}
}
}
}
}
