Detect keypoints in images without corners I am trying to achieve a pattern matching between an image and a scene in which the image is. I am having problems with some images that does not contain corners, since SURF is not able to find keypoints.

Does anybody know any algorithm or method for retrieving keypoints in images without corners? In other words: how can I find an image inside another when this image does not contain corners?

I am using Matlab. Thank you in advance,
The computer vision system toolbox in Matlab includes Feature Detection, Extraction, and Matching. The line, edges, histogram of oriented gradients are all included other than the corner features. And there is also an example on point feature matching in the toolbox (the names are called corners but they are actually not).