OpenCV用BGR通道顺序将图像文件读到内存

OpenCV用BGR通道顺序将图像文件读到内存，在做图像处理之前，要用cvtColor()函数将颜色通道顺序进行转化，否则处理会出错。范例程序如下：

import numpy as np
import matplotlib.pyplot as plt 
import matplotlib.patches as patches
import cv2, math

filename = r'images\2.jpg'
im_bgr = cv2.imread(filename)
im_rgb = cv2.cvtColor(im_bgr, cv2.COLOR_BGR2RGB) #将opencv的BGR通道顺序转换为RGB

fig, ax = plt.subplots(1,2)
ax[0].imshow(im_rgb)
ax[0].set_title("RGB:Original")

ax[1].imshow(im_bgr)
ax[1].set_title("BGR:OpenCV Channel orders")
plt.show()

运行结果： BGR vs RGB