OpenCV 3 Computer Vision Application Programming Cookbook - Third Edition

Describing and matching local intensity patterns

The SURF and SIFT keypoint detection algorithms, discussed in Chapter 8 , Detecting Interest Points, define a location, an orientation, and a scale for each of the detected features. The scale factor information is useful for defining the size of a window of analysis around each feature point. Thus, the defined neighborhood would include the same visual information no matter at what scale of the object to which the feature belongs has been pictured. This recipe will show you how to describe an interest point's neighborhood using feature descriptors. In image analysis, the visual information included in this neighborhood can be used to characterize each feature point in order to make each point ...