possible lanczos replacement
Hello David:
I notice the 'Gamma' versions of these enlargers introduce haloing
around some edges, while the non-gamma versions do not (or it's too
little to see). A naive conversion may be the cause of this
difference. If you could utilize the profile attached to the image,
and generate or load a linear one, you could use LittleCMS to do the
conversion in an assuredly correct way.
The main weaknesses of "our" methods are:
--haloing (but they have less haloing than Lanczos)
--aliasing (but IBFNBQH shows less, although still more than Lanczos, which is more blurry)
--memory usage (an temporary int16 "copy" of the input image has to be created)
Although I have hunches, I still do not understand perfectly how icc profiles
affect enlargement artifacts. (This being said, a monotone method, like nearest
neighbour, bilinear or non-interpolatory B-splines, should
not be affected much by gamma obliviousness; bicubic, Lanczos, EANBQH and
IBFNBQH are NOT monotone.)
This is something I'll have to experiment with.
Thank you for your comments,
Nicolas Robidoux