Do you have sources for each those, especially the uni-directional resizing? The...

avidal · on July 13, 2012

The technique is called Seam Carving: https://en.wikipedia.org/wiki/Seam_carving

It effectively eliminates the least interesting line when performing a resize, allowing you, for example, to resize a skyline by eliminating the uninteresting smaller buildings and gaps.

lilyball · on July 14, 2012

There's even an iOS app called Liquid Scale that will do this right on your iPhone.

http://www.savoysoftware.com/liquidscale/

There may be others but I haven't run across them.

scriptproof · on July 14, 2012

They are usable implementations of all these graphic algos. See: http://www.scriptol.com/programming/graphic-algorithms.php