private static Mat convertTo(Mat mat, int depth) {
		if (mat.depth() == depth) {
			return mat;
		}
		Mat result = new Mat();
		mat.convertTo(result, depth);
		return result;
	}
Guided Image Filter for Color Image
@param origI guidance image (should be a gray-scale/single channel image)
@param p filtering input image (should be a gray-scale/single channel image)
@param r local window radius
@param eps regularization parameter
@param s blocks number, s * s
@param depth image depth
@return filtered image
src/main/java/com/isaac/utils/Filters.java