Size of Matrix OpenCV

opencv opencv-mat
Lakshmi Narayanan picture Lakshmi Narayanan · Dec 25, 2012 · Viewed 233k times · Source

I know this might be very rudimentary, but I am new to OpenCV. Could you please tell me how to obtain the size of a matrix in OpenCV?. I googled and I am still searching, but if any of you know the answer, please help me.

Size as in number of rows and columns.

And is there a way to directly obtain the maximum value of a 2D matrix?

Answer

Michael O picture Michael O · Dec 25, 2012 
cv:Mat mat;
int rows = mat.rows;
int cols = mat.cols;

cv::Size s = mat.size();
rows = s.height;
cols = s.width;

Also note that stride >= cols; this means that actual size of the row can be greater than element size x cols. This is different from the issue of continuous Mat and is related to data alignment.

Related questions

How to crop a CvMat in OpenCV?

I have an image converted in a CvMat Matrix say CVMat source. Once I get a region of interest from source I want the rest of the algorithm to be applied to that region of interest only. For that I …

Read More
How to find out what type of a Mat object is with Mat::type() in OpenCV

I am kind of confused with type() method of Mat object in OpenCV.If I have following lines: mat = imread("C:\someimage.jpg"); type = mat.type(); and type = 16. How do I find out what type of mat matrix is?.I …

Read More
Concatenate Mat in OpenCV

I have a couple of images in Mat objects all with same dimensions I'd like to create one bix cv::Mat object to hold them all So the dimension of the new matrix is: widthNew = widthOld x number of matrices, …

Read More