opencv 修改像素為透明色

import os

import cv2


img = cv2.imread("./test.bmp")

# 轉成透明度圖片
img = cv2.cvtColor(img, cv2.COLOR_BGR2BGRA)

width, height, channel = img.shape

for i in range(width):
    for j in range(height):
        b,g,r,a = img[i][j]
        # 把白色像素改成透明色
        if r == 255 and g == 255 and b == 255:
            # print(r,g,b)
            img[i][j] = [0,0,0,0]

img = cv2.resize(img, (256, 256))

cv2.imwrite("test.png", img)
cv2.waitKey(100000)