python hog 特征提取

代码说明：

import cv2 import numpy as np import math import matplotlib.pyplot as plt class Hog_descriptor(): def __init__(self, img, cell_size=16, bin_size=8): self.img = img self.img = np.sqrt(img / np.max(img)) self.img = img * 255 self.cell_size = cell_size self.bin_size = bin_size self.angle_unit = 360 / self.bin_size # assert type(self.bin_size) == int, "bin_size should be integer," # assert type(self.cell_size) == int, "cell_size should be integer," # assert type(self.angle_unit) == int, "bin_size should be divisible by 360" def extract(self): height, width = self.img.shape gradient_magnitude, gradient_angle = self.global_gradient() gradient_magnitude = abs(gradient_magnitude) cell_gradient_vector = np.zeros((int(height / self.cell_size), int(width / self.cell_size), self.bin_size)) for i in rang