I use this code to delete the border of an image using PIL:

```
def RemoveBlackBorders(img):
    bg = Image.new(img.mode, img.size, img.getpixel((0,0)))
    diff = ImageChops.difference(img, bg)
    diff = ImageChops.add(diff, diff, 2.0, -100)
    bbox = diff.getbbox()
    if bbox:
        return img.crop(bbox)

```

from [here](https://stackoverflow.com/questions/10615901/trim-whitespace-using-pil/10616717#10616717)

And I use this to process all images contained in a folder:

```
def CropImages():
    global FOLDER
    for i in range(1, len(os.listdir(FOLDER))+1):
        image = FOLDER + "\\" + str(i) + ".jpg"
        img = Image.open(image)
        img = RemoveBlackBorders(img)
        img.save(image, "JPEG")

```

Everything works fine and the program does his job. The problem is that if in the folder there is a full black image (which is detected as "border"), the program stuck giving me the error:

```
 AttributeError: 'NoneType' object has no attribute 'save'

```

None of the images in the folder get cropped, even if the black image is the last one of the series. Is there a way to skip this image or delete it (which would be better)?