Opencv Image Matching C

Brute force matcher is simple.
Opencv image matching c. In opencv we use humoments to calculate the hu moments of the shapes present in the input image. Cross platform c python and java interfaces support linux macos windows ios and android. A tutorial for feature based image alignment using opencv. Basics of brute force matcher.
Feature matching between images in opencv can be done with brute force matcher or flann based matcher. We will see how to match features in one image with others. C based iris image verification code using opencv. The image above is the result r of sliding the patch with a metric tm ccorr normed the brightest locations indicate the highest matches.
Template matching is a method for searching and finding the location of a template image in a larger image. Let us discuss step by step approach for calculation of hu moments in opencv. Fortunately we don t need to do all the calculations in opencv as we have a utility function for hu moments. And the closest one.
It takes the descriptor of one feature in first set and is matched with all other features in second set using some distance calculation. As you can see the location marked by the red circle is probably the one with the highest value so that location the rectangle formed by that point as a corner and width and height equal to the patch image is considered the match. The original version is based on c style opencv whereas this version is based on c. C and python example code is shared.
Bf matcher matches the descriptor of a feature from one image with all other features of another image and returns the match based on the distance. It simply slides the template image over the input image as in 2d convolution and compares the template and patch of input image under the template image. It is slow since it checks match with all the features. This iris verification algorithm is originally based on a biometric system for iris osiris version 4 1 developed by telecom sud paris.
Opencv is a highly optimized library with focus on real time applications.