python生成指定尺寸的缩略图,先对图片进行缩小,然后进行裁剪,直到生成规定的尺寸
def MakeThumb(path, sizes=(75, 32, 16)): """ 缩略图生成程序 by Neil Chen sizes 参数传递要生成的尺寸,可以生成多种尺寸 """ base, ext = os.path.splitext(path) try: im = Image.open(path) except IOError: return mode = im.mode if mode not in ('L', 'RGB'): if mode == 'RGBA': # 透明图片需要加白色底 alpha = im.split()[3] bgmask = alpha.point(lambda x: 255-x) im = im.convert('RGB') # paste(color, box, mask) im.paste((255,255,255), None, bgmask) else: im = im.convert('RGB') width, height = im.size if width == height: region = im else: if width > height: delta = (width - height)/2 box = (delta, 0, delta+height, height) else: delta = (height - width)/2 box = (0, delta, width, delta+width) region = im.crop(box) for size in sizes: filename = base + "_" + "%sx%s" % (str(size), str(size)) + ".jpg" thumb = region.resize((size,size), Image.ANTIALIAS) thumb.save(filename, quality=100) # 默认 JPEG 保存质量是 75, 不太清楚。可选值(0~100)