영상에 Impulse Noise 넣기

p=0.2, imax=255, imin=0

int AddImpulseNoise(CRaster& raster, double p, int imax, int imin, CRaster& noised) {
    srand(unsigned(time(NULL)));
    CSize sz = raster.GetSize();
    p = max(min(p, 1),0); //noise probability;
    int np = int(p * sz.cx * sz.cy);
    // clone;
    noised = raster;
    imax = max(min(255, imax), 0); //maximum impulse value;
    imin = min(max(0, imin), 255); //minimum impulse value;
    for (int count = 0, turn = 0; count < np; count++) {
        //x in [0, sz.cx - 1];
        int x = int((sz.cx - 1) * double(rand()) / RAND_MAX); 
        //y in [0, sz.cy - 1];
        int y = int((sz.cy - 1) * double(rand()) / RAND_MAX); 
        if (turn == 0) {
            turn = 1;
            noised.SetPixel(x, y, imax);
        } else {
            turn = 0;
            noised.SetPixel(x, y, imin);
        }
    }
    return 1;
}