Python-OpenCV 图像处理（十一）：直方图方向投影

 import cv2

    
 import numpy as np
    
 from matplotlib import pyplot as plt
    
  
    
 __author__ = "zxsuperstar"
    
 __email__ = "zxsuperstar@163.com"
    
  
    
 """
    
 直方图方向投影， HSV和RGB色彩空间
    
 """
    
 def hist2d_demo(image):
    
     hsv = cv2.cvtColor(image,cv2.COLOR_BGR2HSV)
    
     hist = cv2.calcHist([image],[0,1],None,[180,256],[0,180,0,256])
    
     cv2.imshow("hist2d",hist)
    
     plt.imshow(hist,interpolation="nearest")
    
     plt.title("2d histogram")
    
     plt.show()
    
  
    
  
    
 def back_projection_demo():  #直方图反向投影
    
     sample = cv2.imread("t.jpg")
    
     target = cv2.imread("t2.jpg")
    
     roi_hsv = cv2.cvtColor(sample,cv2.COLOR_BGR2HSV)
    
     target_hsv = cv2.cvtColor(target, cv2.COLOR_BGR2HSV)
    
  
    
     cv2.imshow("sample",sample)
    
     cv2.imshow("target",target)
    
  
    
     roihist = cv2.calcHist([roi_hsv],[0,1],None,[32,32],[0,180,0,256])
    
     cv2.normalize(roihist,roihist,0,255,cv2.NORM_MINMAX) #归一化
    
     dst = cv2.calcBackProject(target_hsv,[0,1],roihist,[0,180,0,256],1)
    
     cv2.imshow("backproject",dst)
    
  
    
  
    
 if __name__ == "__main__":
    
     src = cv2.imread("t.jpg") #blue green red
    
     # cv2.namedWindow("image", cv2.WINDOW_AUTOSIZE)
    
     cv2.imshow("image",src)
    
     
    
     # hist2d_demo(src)
    
     back_projection_demo()
    
     cv2.waitKey(0)
    
     cv2.destroyAllWindows()