Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

Visualizing HOG

Carl Vondrick, Aditya Khosla, Hamed Pirsiavash, Tomasz Malisiewicz, and Antonio Torralba have developed a HOG visualization technique called HOGgles (HOG goggles). For a summary of HOGgles, as well as links to code and publications, refer to Carl Vondrick's MIT web page at http://www.cs.columbia.edu/~vondrick/ihog/index.html. As one of their test images, Vondrick et al. use the following photograph of a truck:

Vondrick et al. produce the following visualization of the HOG descriptors, based on an approach from Dalal and Triggs' earlier paper:

Then, applying HOGgles, Vondrick et al. invert the feature description algorithm ...