Source formatting
Do not test performance descriptors on match
Adds gaussian blur utility
Uses four channel grayscale on sobel
Fixes window offsets to not access float array indexes;
Fixes image offsets cache to avoid generating different descriptors for different image sizes;
Uses Brief-64 by default
Adds Brief reciprocal match to remove matches outliers by testing matches on both directions
Updates demos
Fixes breaking on reciprocal matching on empty keypoints
Exposes fast threshold as parameter
Build
Adds example tracking using Brief with Fast