OpenCV Error: Assertion failed (i < src.channels()) in cvSplit

Question

i am running a basic application using openCV for C++. I am attempting to split the image into rgb components using cvSplit() as below:

CvMat* mat;

//initialize mat

CvMat* b = cvCreateMat(mat->rows, mat->cols, CV_8UC1);
CvMat* g = cvCreateMat(mat->rows, mat->cols, CV_8UC1);
CvMat* r = cvCreateMat(mat->rows, mat->cols, CV_8UC1);
cvSplit(mat, b, g, r, NULL );

It builds just fine, but when I attempt to run it, I get the following error:

OpenCV Error: Assertion failed (i < src.channels()) in cvSplit, file /home/username/Downloads/OpenCV-2.4.0/modules/core/src/convert.cpp, line 1196
terminate called after throwing an instance of 'cv::Exception'

What does this error mean, and how can I solve the problem?

Answer 1

The IplImage you are using to create the Mat should be in color. You need three channels to be able to use cvSplit . You can check this with IplImage->nChannels in your debugger.