png格式:不属于压缩性。 png转换成jpg： from PIL import Imageimport cv2 as cvimport osdef PNG_JPG(PngPath): img = cv.imread(PngPath, 0) w, h = img.shape[::-1] infile = PngPath outfile = os.path.splitext(infile)[0] + ".jpg" img = Image.open(infile) img = img.resize((int(w / 2), int(h / 2)), Image.ANTIALIAS) try: if len(img.split()) == 4: # prevent IOError: cannot write mode RGBA as BMP r, g, b, a = img.split() img = Image.merge("RGB", (r, g, b)) img.convert('RGB').save(outfile, quality=70) os.remove(PngPath) else: img.convert('RGB').save(outfile, quality=70) os.remove(PngPath) return outfile except Exception as e: print("PNG转换JPG 错误", e) 转换一张图片： #############转换一张图片#################import osimg='img.png'Path='./'if img.endswith('.png'): PngPath= Path + img PNG_JPG(PngPath) 转换多张图片： ################转换多张图片#####################import ospath_root = os.getcwd()Path='/home/jovyan/work/data/gyx/competition/train_2/'img_dir = os.listdir(Path)for img in img_dir: if img.endswith('.png'): PngPath= Path + img PNG_JPG(PngPath)img_dir = os.listdir(Path)for img in img_dir: print(img)