There's standalone utility catimg (https://github.com/posva/catimg) written in C. It supports animation and 2x "retina" resolution using unicode symbols.
Here's blog post about it: http://posva.net/shell/retro/bash/2013/05/27/catimg/
For those that are interested, I've also released my approach to imagery in the terminal (Python):
I would also be happy to accept pull requests from you, adding true color support to hiptext.