5-7 灰度直方图均衡化

# 本质: 统计每个像素灰度 出现的概率 0-255 p
# 累计概率
# 1 0.2 0.2 第一个灰度等级它出现的概率是0.2
# 2 0.3 0.5 第二个灰度等级它出现的概率是0.3
# 3 0.1 0.6 第三个灰度等级它出现的概率是0.1
# 256
# 100 0.5 255*0.5 = new 



import cv2
import numpy as np
import matplotlib.pyplot as plt
img = cv2.imread(‘image0.jpg‘,1)
imgInfo = img.shape
height = imgInfo[0]
width = imgInfo[1]
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
count = np.zeros(256,np.float)
for i in range(0,height):
    for j in range(0,width):
        pixel = gray[i,j]
        index = int(pixel)
        count[index] = count[index]+1
for i in range(0,255):
    count[i] = count[i]/(height*width)
# 计算累计概率
sum1 = float(0)
for i in range(0,256):
    sum1 = sum1+count[i]
    count[i] = sum1
print(count)

cv2.waitKey(0)