olooney

'''
PIL's Image.thumbnail() returns an image that fits inside of a given size (preserving aspect ratios)
but the size of the actual image will vary and is certainly not guaranteed to be the requested size.
This is often inconvenient since the size of the returned thumbnail cannot be predicted. The django-thumbs
library solves this for square thumbnails by cropping the image to a square and then resizing it. However,
this only works for exact squares.

This function generalizes that approach to work for thumbnails of any aspect ratio. The returned thumbnail
is always exactly the requested size, and edges (left/right or top/bottom) are cropped off to adjust to
make sure the thumbnail will be the right size without distorting the image.