A comparison of image features for registering LWIR and visual images

Abstract

This paper presents a comparison of several established and recent image feature-descriptors to register long wave infra-red images in the 8–14 m band to visual band images. The feature descriptors were chosen to include robust algorithms, SURF and SIFT — and fast algorithms, BRISK and BFROST. To evaluate the feature-descriptors a ground truth was created by determining the intrinsic and extrinsic camera calibration parameters for the cameras and using this to photogrammetrically relate pixel positions between the images. The inlier results of each feature descriptor for the top 20%, 50% and 100% of the matches (based on match strength) were used to create a homography. The average pixel error between the homography reprojected feature points and the photogrammetric reprojection was used as the error. The results show that none of the descriptors perform well in standard form, with BFROST faring slightly better than the other algorithms. This suggests a need to modify the algorithms to detect physical/structural features and de-emphasise textural features.