In Tk, you can use the -subsample option in the copy() method call from a Photo widget to shrink any type of image you have loaded. This only allows for integer reduction ratios as far as I can tell, but is better than nothing. See an example of this in this node-- but note I've had little luck solving the memory issues. Your mileage may vary. This should not run afoul of any patents since you are only loading the image from a gif file, and not creating a new gif.