import cv2
import os
import numpy as nproot = "./test"
for file in os.listdir(root):# 读取图片image = cv2.imread(os.path.join(root, file), cv2.IMREAD_UNCHANGED)new = np.zeros((image.shape[0], image.shape[1], image.shape[2]), np.uint8)# 检查图片是否为RGBA格式print(image.shape)if image.shape[2] == 4:print("图片是RGBA格式")# 获取透明度通道new[:, :, :3] = image[:, :, :3]else:print("图片不是RGBA格式")# 广播机制new[:, :, 3] = 30cv2.imwrite("./test/alpha30.png", new)# for i in image.shape[0]:#     for j in image.shape[1]:#         new[i][j][3] = 30