[theora] NHW Image codec - improvement of precision

Raphael Canut nhwcodec at gmail.com
Wed Jul 25 07:50:17 PDT 2012

Hi again,

I have improved precision of my codec (on the encoder and decoder).I have
also improved the -h1 quality setting.-Source code and binaries at

I am still trying to improve precision of my codec, with keeping my
low-complexity (fast) approach.
I do not totally use the reference (and impressive) block prediction with
different modes + residual coding scheme, but I just apply residual coding
on the first order wavelet "image" (for example for a 512x512 image, I just
code the errors on the 256x256 wavelet "high-resolution" part), hence the
lack of precision.I try to compensate it with a little more neatness of the
wavelet 5/3 filterbank, but that's right that precision seems visually more

Any opinion on this approach or on the codec in general is very welcome.

Many thanks again,
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/theora/attachments/20120725/9386a3d4/attachment.htm 

More information about the theora mailing list