Function GetMagsAndOrients_GeneralCase

jni/stasm/hat.cpp:160–193

// to 0 and thus contributes nothing later in TrilinearAccumulate.

static void GetMagsAndOrients_GeneralCase(
    vec_double&       mags,         // out
    vec_double&       orients,      // out
    const int         ix,           // in: x coord of center of patch
    const int         iy,           // in: y coord of center of patch
    const int         patchwidth,   // in
    const MAT&        magmat,       // in
    const MAT&        orientmat,    // in
    const vec_double& pixelweights) // in
{
    const int halfpatchwidth = (patchwidth-1) / 2;
    int ipix = 0;
    for (int x = iy - halfpatchwidth; x <= iy + halfpatchwidth; x++)
    {
        const double* const magbuf    = Buf(magmat)    + x * magmat.cols;
        const double* const orientbuf = Buf(orientmat) + x * orientmat.cols;

        for (int y = ix - halfpatchwidth; y <= ix + halfpatchwidth; y++)
        {
            if (x < 0 || x >= magmat.rows || y < 0 || y >= magmat.cols)
            {
                mags[ipix] = 0;    // off image
                orients[ipix] = 0;
            }
            else                   // in image
            {
                mags[ipix]    = pixelweights[ipix] * magbuf[y];
                orients[ipix] = orientbuf[y];
            }
            ipix++;
        }
    }
    CV_DbgAssert(ipix == NSIZE(mags));
}

// Calculate the image patch gradient mags and orients for
// an image patch that is entirely in the image boundaries.