Matlab to OpenCV Mat

The Code

int matlab2opencv(cv::Mat &img, const mxArray *&mat){
mwSize num_dims = mxGetNumberOfDimensions(mat);
const mwSize *dims = mxGetDimensions(mat);

//for (int i = 0; i < num_dims; i++){
//  mexPrintf("%d-th:%d\n", i, dims[i]);
//}

if (num_dims != 3 || dims[2] != 3){
mexPrintf("error image dimensions!\n");
return EXIT_FAILURE;
}

if (!mxIsSingle(mat)){
mexPrintf("the input matrix must be double with value in [0,1].");
return EXIT_FAILURE;
}

int rows = dims[0];
int cols = dims[1];
int nchs = 3;

img.create(rows, cols, CV_32FC3);

float *mat_data = (float*)mxGetData(mat);
float *mat_temp_ptr = NULL;

int layer_size = rows*cols;

for (int ch = 0; ch < nchs; ch++){
mat_temp_ptr = mat_data + ch*layer_size;
int rd = 2 - ch;
for (int c = 0; c < cols; c++){
for (int r = 0; r < rows; r++){
img.at<cv::Vec3f>(r, c)[rd] = mat_temp_ptr[c*rows+r];
}
}
}

return EXIT_SUCCESS;
}