Using Mat::at(i,j) in opencv for a 2-D Mat object
Img_mat
is a 3 channeled image. Each channel consists of pixel values uchar
in data type.
So with split(Img_mat, BGR)
the Img_mat
is split into 3 planes of blue, green and red which are collectively stored in a vector BGR
. So BGR[0]
is the first (blue) plane with uchar
data type pixels...hence it will be
int dataB = (int)BGR[0].at<uchar>(i,j);
int dataG = (int)BGR[1].at<uchar>(i,j);
so on...
You have to specify the correct type for cv::Mat::at(i,j)
. You are accessing the pixel as int
, while it should be a vector of uchar
. Your code should look something like this:
IplImage* img = 0;
img = cvLoadImage("nature.jpg");
if(img != 0)
{
Mat Img_mat(img);
std::vector<Mat> BGR;
split(Img_mat, BGR);
Vec3b data = BGR[0].at<Vec3b>(i,j);
// data[0] -> blue
// data[1] -> green
// data[2] -> red
}