Mat 픽셀값 접근 (at)

Mat LeftImg = imread("1L.jpg");

for (int i = 0 ; i < LeftImg.cols ; i++)
{
	for (int j = 0 ; j < LeftImg.rows ; j++)
	{
		if(	LeftImg.at<Vec3b>(j,i)[0] <= 10 ||
			LeftImg.at<Vec3b>(j,i)[1] <= 10 ||
			LeftImg.at<Vec3b>(j,i)[2] <= 10 )
		{ 
			LeftImg.at<Vec3b>(j,i)[0] = 255; //Blue
			LeftImg.at<Vec3b>(j,i)[1] = 255; //Green
			LeftImg.at<Vec3b>(j,i)[2] = 255; //Red
		}
		else
		{
			break;
		}
	}
}