** REQUIRES OPENCV MANAGER ** https://play.google.com/store/apps/details?id=org.opencv.engine

This app compares the reference image to the images in the added list. It uses ORB feature detector with BRIEF descriptor extractors. It uses BRUTEFORCE_HAMMING method to match the descriptors. Also, based on preference, app can also check the homography of the matched keypoints with LMED (least of median squares) and remove the outliners to give a better result.

How to use:
1 - Move the vision wherever you want, take pics along the way by using ADD button.
2 - You can also take a reference picture, that you want to be recognized. When you click it, it will be shown on the right of the camera view.
3 - When you are done, and make sure you have added images and have a reference image, click the Find Match button. It will calculate the keypoints of each image and the reference image and apply the matching algorithm.
4 - After matching and comparing, it will show the best match among all matches.
5 - You can also use Homography Off/On switch to provide more accurate results.
6 - Also, you can use Images only/with matches switch to show which keypoints are matched. REMEMBER, you have to click find match again to see the effect of Homography and Matches switch.

This app is still in development, actually being used by another project but I put it on for cool demonstration!

Source code available: https://github.com/mustafaakin/image-matcher