09_OpenCV彩色图片直方图
import cv2
import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline
img = cv2.imread('computer.jpeg', 1)
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
plt.imshow(img)
plt.show()
plot绘制直方图
plt.hist(img.ravel(), 256) #ravel() 二维降一维 256灰度级的分组情况 plt.show()
# plot绘制opencv返回的直方图值
histb = cv2.calcHist([img], [0], None, [256], [0, 255]) plt.plot(histb, color='b') plt.show()
