Hi,
How can I extract a patch from an image, by knowing the image file to which it belongs? The patch is given with its center (the patch has the shape of an ellipse), its orientation, its scale, and its affine transformation with respect to a unit circle, and a set of descriptors.Any hints or code sample? Thanks!
First you will need to determine the bounding rectangle for the ellipse. Here is the sample code for it,
Rect patch = your_ellipse.boundingRect();
Secondly to extract the patch you will need to extract the ROI of the patch. Here is the sample code for it,
Mat ROI(image,patch);
Hope it helps.
Thanks, it was a good starting point. Actually I was thinking about something like this http://nashruddin.com/OpenCV_Circular_ROI , where the region of interest can be a circle, ellipse or any shape. The only thing in this solution not suitable for my case, is that the extracted circle patch has a color, and I would like to be just an image part. Do you have any suggestions for this?
I don't think its possible. The extracted region will always need to be a square or a rectangle. What you can do is to extract the rectangular region and then apply a binary mask with your shape to the rectangular region. The output will be such that all the pixels within your shape has colour and everything outside the shape will be black.
Asked: 2012-10-10 11:32:29 -0600
Seen: 4,009 times
Last updated: Oct 10 '12
