cv::Vec3b determinePixelValueByConv(cv::Mat& neigbourhood){
	int coeffs[3][3] = { { -1, -1, -1 }, { -1, 8, -1 }, { -1, -1, -1 } };

	cv::Mat_<cv::Vec3b> _neigbourhood = neigbourhood;
	cv::Vec3b centralPixel = _neigbourhood(1, 1);
	cv::Vec3b outputPixel = cv::Vec3b();

	for (int k = 0; k < 3; k++){
		int product_sum = 0;
		for (int i = 0; i < _neigbourhood.rows; ++i){
			for (int j = 0; j < _neigbourhood.cols; ++j){
				product_sum += (_neigbourhood(i, j)[k] * coeffs[i][j]);
			}
		}
		outputPixel[k] = cutToRange((int)(product_sum));
	}
	
	return outputPixel;

}



cv::Mat edgingConvolution(cv::Mat& I){
	cv::Mat imageCopy = shallowCopy(I);
	cv::Mat_<cv::Vec3b> _I = I;

	for (int i = 1; i < I.rows - 1; i++){
		for (int j = 1; j < I.cols - 1; j++){
			cv::Mat neigbourhood = imageCopy(cv::Rect(j - 1, i - 1, 3, 3));
			cv::Vec3b outputPixel = determinePixelValueByConv(neigbourhood);
			_I(i, j)[0] = outputPixel[0];
			_I(i, j)[1] = outputPixel[1];
			_I(i, j)[2] = outputPixel[2];
		}
	}
	I = _I;
	return I;

}