MATLAB sub2ind / ind2sub in OpenCV / C ++

Question

Are there any functions in OpenCV that are equal to MATLAB sub2ind and ind2sub ? I need both functions for my C ++ application. If OpenCV does not have these functions, are there any C ++ libraries that provide equivalent functionality?

Answer 1

You can write them yourself:

 int sub2ind(const int row,const int col,const int cols,const int rows) { return row*cols+col; } void ind2sub(const int sub,const int cols,const int rows,int &row,int &col) { row=sub/cols; col=sub%cols; } 

Answer 2

Here is my code for a 2D matrix. I tested it.

 cv::Mat Utilities::Sub2Ind(int width, int height, cv::Mat X, cv::Mat Y) { /*sub2ind(size(a), rowsub, colsub) sub2ind(size(a), 2 , 3 ) = 6 a = 1 2 3 ; 4 5 6 rowsub + colsub-1 * numberof rows in matrix*/ std::vector<int> index; cv::transpose(Y,Y); cv::MatConstIterator_<int> iterX = X.begin<int>(), it_endX = X.end<int>(); cv::MatConstIterator_<int> iterY = Y.begin<int>(), it_endY = Y.end<int>(); for (int j = 0; j < X.cols; ++j,++iterX) { //running on each col of y matrix for (int i =0 ;i < Y.cols; ++i,++iterY ) { int rowsub = *iterY; int colsub = *iterX; int res = rowsub + ((colsub-1)*height); index.push_back(res); } int x = 5; } cv::Mat M(index) ; return M; }