OpenImageIO/oiio — pull request #572 by lgritz (2013-04-13 03:20:36+00:00)
Title: Add/subtract cleanup

IBA and oiiotool cleanup of add & sub

* Implement IBA::sub
* More robust handling of "full/display" rois in IBAprep
* Refactor oiiotool --add and --sub to allow different image sizes and handle pixel and display windows properly.
* Clarify comments
* Testsuite tests for add & sub