title: Feature detection in OpenCV to merge two images
body: <p>Is it somehow possible to merge two images captured by searching for identical features in OpenCV in both images?
  My images will always contain sheets of papers which are too big to be captured in one single frame thus I need to take two or more frames - the images are captured so that there is some overlapping area, see:</p>
  
  <p>Top picture: <a href="http://i.imgur.com/0tvGVKG.jpg" rel="nofollow">http://i.imgur.com/0tvGVKG.jpg</a></p>
  
  <p>Bottom picture: <a href="http://i.imgur.com/nmlO4gL.jpg" rel="nofollow">http://i.imgur.com/nmlO4gL.jpg</a></p>
  
  <p>IDEA: Restrict features to only move up/down and not to the right etc.. Even more so, the length of all vectors between two identical features in both images has to be more or less identical, as the area is overlapping. OpenCV also only has to look at the very bottom of picture one and at the very top of picture two for overlapping features. All the other areas are NOT of interest...</p>
  
  <p>Edit: Okay I found some sources about this finally with some good links in the answers: <a href="https://stackoverflow.com/questions/10855825/how-to-find-overlapping-region-between-images-in-opencv">how to find overlapping region between images in opencv?</a></p>