直接看下面python代码
def save_png():
image_path = 'src.png'
img = cv2.imread(image_path, cv2.IMREAD_UNCHANGED)
img[63,63,:] = [255,0,0,128]
print(img)
cv2.imwrite('dst.png', img, [int(cv2.IMWRITE_PNG_COMPRESSION), 9])
cv2.namedWindow('win', 0)
cv2.imshow('win', img)
cv2.waitKey(0)
参考
https://blog.csdn.net/litdaguang/article/details/45438297
https://www.jianshu.com/p/7fcfc6253c81
