int width;                  // width of the image
int height;                 // height of the image
byte image[width*height];   // current image
byte updatingMask[*height]; // updating mask (1==updating allowed)

int subsamplingFactor = 16; // amount of random subsampling

int numberOfSamples = 20;   // number of samples per pixel
byte samples[width*height][numberOfSamples]; // background model

for (int p = 0; p < width*height; p++) 
	if (updatingMask[p] == 1) { // updating is allowed

		// eventually updates the model of p (in-place updating)
		int randomNumber = getRandomIntegerIn(1, subsamplingFactor);
		if (randomNumber == 1) { // random subsampling
			// randomly selects a sample in the model to be replaced 
			int randomNumber = getRandomIntegerIn(0, numberOfSamples - 1);
			samples[p][randomNumber] = image[p];
		}

		// eventually diffuses in a neighboring model (spatial diffusion)
		int randomNumber = getRandomIntegerIn(1, subsamplingFactor);
		if (randomNumber == 1) { // random subsampling
			// chooses a neighboring pixel randomly
			q = getPixelLocationFromTheNeighborhoodOf(p);
			// diffuses the current value in the model of q
			// (uncomment the following check to inhibit diffusion across the border of the updating mask)
			// if (updatingMask[q] == 1) {
				int randomNumber = getRandomIntegerIn(0, numberOfSamples - 1);
				samples[q][randomNumber] = image[p];
			// }
		}

	} // end of "if"
} // end of "for"