Example #1
0
static void InitGradMagAndOrientMats(
    MAT&         magmat,    // out: grad mag mat
    MAT&         orientmat, // out: grad ori mat
    const Image& img)       // in:  ROI scaled to current pyramid level
{
    const int nrows = img.rows, nrows1 = img.rows-1;
    const int ncols = img.cols, ncols1 = img.cols-1;
    const double bins_per_degree = BINS_PER_HIST / 360.;

    magmat.create(nrows, ncols);
    orientmat.create(nrows, ncols);

    for (int y = 0; y < nrows1; y++)
    {
        const byte* const buf    = (byte*)(img.data) + y     * ncols;
        const byte* const buf_x1 = (byte*)(img.data) + y     * ncols + 1;
        const byte* const buf_y1 = (byte*)(img.data) + (y+1) * ncols;

        double* const magbuf    = Buf(magmat)    + y * ncols;
        double* const orientbuf = Buf(orientmat) + y * ncols;

        for (int x = 0; x < ncols1; x++)
        {
            const byte   pixel  = buf[x];
            const double xdelta = buf_x1[x] - pixel;
            const double ydelta = buf_y1[x] - pixel;

            magbuf[x] = sqrt(SQ(xdelta) + SQ(ydelta));

            double orient =
                RadsToDegrees(atan2(ydelta, xdelta)); // -180 <= orient < 180
            if (orient < 0)
                orient += 360;                        // 0 <= orient < 360
            orientbuf[x] = orient * bins_per_degree;  // 0 <= orient < BINS_PER_HIST
        }
    }
    // fill bottom and right edges
    magmat.row(nrows1) = 0;
    magmat.col(ncols1) = 0;
    orientmat.row(nrows1) = 0;
    orientmat.col(ncols1) = 0;
}
Example #2
0
static void ZapSmallEigs(
    MAT& eigvals,         // io
    MAT& eigvecs)         // io
{
    const double min = eigvals(0) / 1e6;
    CV_Assert(min > 0);
    for (int eig = 0; eig < NSIZE(eigvals); eig++)
        if (eigvals(eig) < min)
        {
            eigvals(eig) = 0;
            eigvecs.row(eig) = 0; // set all eigenvector elems to 0
        }
}