问题描述

png图像有的可能包含透明通道，包含透明通道的png格式图像转换成jpg格式图像时，会出现异常的颜色值。非通过直接修改扩展名的方法，读取后又保存的。直接通过修改扩展名的方法读取保存后没有异常，但是本质没改变。

对应图像属性

解决方法

img_path = '/special_data'out_path = '/special_data_jpg'for img_name in os.listdir(img_path):img = Image.open(os.path.join(img_path, img_name))print(img_name, img.mode)img_name_base, img_name_ext = os.path.splitext(img_name)if img_name_ext in ['.png', '.PNG']:if img.mode == 'RGBA':img_arr = np.array(img)img_white = np.ones((img_arr.shape[0], img_arr.shape[1], 3), np.uint8) * 255alpha = img_arr[:, :, 3]alpha = alpha[:, :, np.newaxis] / 255.img_out = img_arr[:, :, :3] * alpha + img_white * (1 - alpha)img_out = np.clip(img_out, 0, 255)img_out = img_out.astype(np.uint8)save_img = Image.fromarray(img_out)elif img.mode == 'P':img = img.convert('RGBA')img_arr = np.array(img)img_white = np.ones((img_arr.shape[0], img_arr.shape[1], 3), np.uint8) * 255alpha = img_arr[:, :, 3]alpha = alpha[:, :, np.newaxis] / 255.img_out = img_arr[:, :, :3] * alpha + img_white * (1 - alpha)img_out = np.clip(img_out, 0, 255)img_out = img_out.astype(np.uint8)save_img = Image.fromarray(img_out)else:if img.mode in ['1', 'L']:save_img = img.convert('RGB')elif img.mode == 'CMYK':img = ImageCms.profileToProfile(img, 'USWebCoatedSWOP.icc', 'sRGB Color Space Profile.icm',renderingIntent=0, outputMode='RGB')save_img = imgelse:save_img = imgoutput_img_name = os.path.splitext(img_name)[0] + '.jpg'print(save_img.mode)save_img.save(os.path.join(out_path, output_img_name))