图像处理11：添加logo

把 OpenCV 的标志放到另一幅图像上。如果使用加法，颜色会改变，如果使用混合，会得到透明效果，但是我不想要透明。如果是矩形可以象上一章那样使用 ROI。但是他不是矩形。但是我们可以通过下面的按位运算实现：

import cv2import numpy as npimg1 = cv2.imread('F:/beauty.jpg')img2 = cv2.imread('F:/logo.jpg')# I want to put logo on top-left corner, So I create a ROIrows,cols,channels = img2.shaperoi = img1[0:rows, 0:cols ]# Now create a mask of logo and create its inverse mask alsoimg2gray = cv2.cvtColor(img2,cv2.COLOR_BGR2GRAY)ret, mask = cv2.threshold(img2gray, 10, 255, cv2.THRESH_BINARY)#参数可以改变提取logo的颜色mask_inv = cv2.bitwise_not(mask)# Now black-out the area of logo in ROIimg1_bg = cv2.bitwise_and(roi,roi,mask = mask_inv)# Take only region of logo from logo image.img2_fg = cv2.bitwise_and(img2,img2,mask = mask)# Put logo in ROI and modify the main imagedst = cv2.add(img1_bg,img2_fg)img1[0:rows, 0:cols ] = dstcv2.imshow('res',img1)cv2.waitKey(0)cv2.destroyAllWindows()

结果图：