1、显示直方图

用到了matlab画图模块matplotlib

还没安装的话：

pip install matplotlib

用到了函数

典型代码如下

#引入opencv模块

import cv2 as cv

#引入numpy模块

import numpy as np

#引入sys模块

import sys

#引入matplotlib模块

from matplotlib import pyplot as plt

#绘制直方图

def image_hist(img):

color = ('blue','green','red')

for i,color in enumerate(color):

hist = cv.calcHist([img],[i],None,[256],[0,256])

plt.plot(hist,color=color)

plt.xlim([0,256])

plt.show()

def img_test():

img = cv.imread('E:/chenopencvblogimg/lena.jpg')

#判断是否读取成功

if img is None:

print("Could not read the image,may be path error")

return

cv.namedWindow("origin Pic",cv.WINDOW_NORMAL)

cv.imshow("origin Pic",img)

image_hist(img)

#让显示等待键盘输入维持在那里，否则程序跑完就闪退啦！

cv.waitKey(0)

#销毁窗口

cv.destroyAllWindows()

if __name__ == '__main__':

sys.exit(img_test() or 0)

2、直方图均衡化

#引入opencv模块

import cv2 as cv

#引入numpy模块

import numpy as np

#引入sys模块

import sys

#引入matplotlib模块

from matplotlib import pyplot as plt

#直方图均衡化，用在灰度图上

def euqal_hist(img):

gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)

dst = cv.equalizeHist(gray)

return dst

def img_test():

img = cv.imread('E:/chenopencvblogimg/equalhist.jpg')

#判断是否读取成功

if img is None:

print("Could not read the image,may be path error")

return

cv.namedWindow("origin Pic",cv.WINDOW_NORMAL)

cv.imshow("origin Pic",img)

img_show = euqal_hist(img)

cv.namedWindow("equal_hist",cv.WINDOW_NORMAL)

cv.imshow("equal_hist",img_show)

#让显示等待键盘输入维持在那里，否则程序跑完就闪退啦！

cv.waitKey(0)

#销毁窗口

cv.destroyAllWindows()

if __name__ == '__main__':

sys.exit(img_test() or 0)

这幅测试图的效果是夸张的好

3.局部直方图均衡化

注意：参数可以自己选择和设置，可以不用默认！！！

#引入opencv模块

import cv2 as cv

#引入numpy模块

import numpy as np

#引入sys模块

import sys

#引入matplotlib模块

from matplotlib import pyplot as plt

#直方图均衡化，用在灰度图上

def euqal_hist(img):

gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)

dst = cv.equalizeHist(gray)

return dst

#局部直方图均衡化，用在灰度图上

def clahe_hist(img):

gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)

clahe = cv.createCLAHE()

#clahe = cv.createCLAHE(clipLimit=2.0,tileGridSize=(8,8))

dst = clahe.apply(gray)

return dst

def img_test():

img = cv.imread('E:/chenopencvblogimg/equalhist.jpg')

#判断是否读取成功

if img is None:

print("Could not read the image,may be path error")

return

cv.namedWindow("origin Pic",cv.WINDOW_NORMAL)

cv.imshow("origin Pic",img)

img_show = euqal_hist(img)

cv.namedWindow("equal_hist",cv.WINDOW_NORMAL)

cv.imshow("equal_hist",img_show)

img_show = clahe_hist(img)

cv.namedWindow("clahe_hist",cv.WINDOW_NORMAL)

cv.imshow("clahe_hist",img_show)

#让显示等待键盘输入维持在那里，否则程序跑完就闪退啦！

cv.waitKey(0)

#销毁窗口

cv.destroyAllWindows()

if __name__ == '__main__':

sys.exit(img_test() or 0)