SummedAreaTableRegion.cpp

/* -*-c++-*- */

#include "SummedAreaTableRegion"
#include "SummedAreaTable"

/**
 * A subregion in a SummedAreaTable.
 */
double SatRegion::getRegionWeight() const {
    double f00 = _sat->I1(_x, _y);
    double f10 = _sat->I1(_x + _w, _y);
    double f01 = _sat->I1(_x, _y + _h);
    double f11 = _sat->I1(_x + _w, _y + _h);

    return _sum * (f00 + f10 + f01 + f11) * 0.25;
}

double SatRegion::getCornerDeviation() const {
    const Vec2d c = centroid();
    const double fav = _sat->I1(c[0], c[1]);

    double f00fav = _sat->I1(_x, _y) - fav;
    double f10fav = _sat->I1(_x + _w, _y) - fav;
    double f01fav = _sat->I1(_x, _y + _h) - fav;
    double f11fav = _sat->I1(_x + _w, _y + _h) - fav;

    f00fav *= f00fav;
    f10fav *= f10fav;
    f01fav *= f01fav;
    f11fav *= f11fav;

    return 0.5 * sqrt(f00fav + f10fav + f01fav + f11fav);
}

void SatRegion::create(const int x, const int y, const uint w, const uint h,
                       const SummedAreaTable* sat) {
    _x = x;
    _y = y;
    _w = w;
    _h = h;
    _sat = sat;

    _sum = _sat->sum(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                     y + (h - 1));

    _r = _sat->sumR(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                    y + (h - 1));

    _g = _sat->sumG(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                    y + (h - 1));

    _b = _sat->sumB(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                    y + (h - 1));

    _sum2 = _sat->sum2(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                       y + (h - 1));

    _sum3 = _sat->sum3(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                       y + (h - 1));

    _sum4 = _sat->sum4(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                       y + (h - 1));

    _sum5 = _sat->sum5(x, y, x + (w - 1), y, x + (w - 1), y + (h - 1), x,
                       y + (h - 1));
}