HOG (Histograms of Oriented Gradients) type quick feature extracting method

The invention discloses a HOG (Histograms of Oriented Gradients) type quick feature extracting method, and belongs to the technical field of computer die recognition. The method comprises the steps of 1, preprocessing an image; 2, calculating gradient of each pixel of the image, and dividing the image into cells and blocks; 3, calculating the HOG of each cell; 4, normalizing the HOG of each cell in each block; 5, collecting the HOG in each block, and combining into the HOG feature of the image; when calculating the HOG of each cell, each cell is divided into four sub-cells, the sub-cell adjacent to any cell M is selected from other cells in M blocks, and then all pixels in the cell M and all pixels in the selected sub-cells are subjected to tri-interpolation so as to obtain the HOG of the cell M. With the adoption of the method, the feature extracting speed can be greatly increased whole ensuring the effectiveness of the features.