Find small image coordinates within a large image

Asked Oct 23 '14 at 17:36

Active Oct 23 '14 at 21:42

Viewed 820 times

enter image description here I have 2 images. One is a smaller version of the other and has also been cropped in all sides. I need to find the exact location of the smaller image inside the large one. Using OpenCV Homography function I managed to achieve it only if both images had the same scale: http://docs.opencv.org/doc/tutorials/features2d/feature_homography/feature_homography.html#feature-homography

For images with different scales, I suppose I need to downscale the large image to match the smaller one, but how can I find the scaling factor ?

edited Oct 23 '14 at 21:42

asked Oct 23 '14 at 17:36

Musti Rabin

e.g. by testing for "each" scaling factor in a loop. – Micka Oct 23 '14 at 19:34
Please add images to illustrate the problem. – karlphillip Oct 23 '14 at 21:02
You can also use a recognition approach, for instance as described in [this answer](http://stackoverflow.com/a/10169025/1633399). – BConic Oct 24 '14 at 09:06
If you use SIFT or SURF (as in your link), it should work since the descriptors are scale-invariant. – Dennis Oct 24 '14 at 11:07
how is this related to image-stitching?! – Samer Oct 31 '14 at 16:09

0 Answers0