Feature point identification and regional registration in sequences of non-structured texture images

The authors propose a new methodology for identification of feature points in non-structured texture images and suggest how they can be used to perform regional registration when precise (pixel-wise) registration is not possible. The specific motivation behind this work is the analysis of sequences of mammographic images of the same patient with the objective of detecting changes indicative of cancer. Because of intractability of precise mammogram registration the authors propose regional mammogram registration and comparison by using feature points. This paper focuses on extraction and pairing of the feature points. The proposed technique is tested on 50 mammogram pairs and verified by visual inspection involving three human subjects, an experienced radiologist and two casual observers