A feature method that counts edge directions in small parts of an image.
HOG is like a sidewalk sketch artist for photos. It skips the pretty face and notes which way the outlines bend.
It helped old-school vision spot walkers and objects. It turns edges into clues a computer can use.
Computer Vision
HOG gives Computer Vision useful clues from image edges.
Feature-engineering
HOG is a hand-made feature for turning pictures into numbers.
Object Detection
HOG was often used to find people in early Object Detection.
SVM
HOG finds outline clues, and an SVM judges the class.