void pyramid(Node * node)
{
	Image image = node->image;
	int N = max(image.width,image.height);
	
	if (N > 2)
	{
		int width = image.width / 2;
		int height = image.height / 2;
		node->min = new Node(width / 2, height /2);
		node->max = new Node(width / 2, height /2);
		node->middle = new Node(width / 2, height /2);
		for (int i = 0; i < width; i++)
			for (int j = 0; j < height; j++)
			{
				node->min.image[i,j] = min(image[i * 2, j * 2],image[i * 2 + 1, j * 2],image[i * 2, j * 2 + 1],image[i * 2 + 1, j * 2 + 1]);
				node->max.image[i,j] = max(image[i * 2, j * 2],image[i * 2 + 1, j * 2],image[i * 2, j * 2 + 1],image[i * 2 + 1, j * 2 + 1]);
				node->middle.image[i,j] = (image[i * 2, j * 2]+image[i * 2 + 1, j * 2]+image[i * 2, j * 2 + 1]+image[i * 2 + 1, j * 2 + 1]) / 4;
			}
		pyramid(node->min);
		pyramid(node->max);
		pyramid(node->middle);
	}
	return;
}