[daala] Number of components, is there room for alpha?

[Thomas Daede]

Daala has a technique for inter-plane prediction, called Chroma from
Luma. You can read more about it here:

http://people.xiph.org/~xiphmont/demo/daala/demo4.shtml

This technique will also work for any other channels, e.g. Alpha from
Luma. While there is no alpha plane support yet, it would just consist
of increasing the maximum number of planes, and adding read/write
support for alpha-containing files.

On 05/01/2015 05:04 AM, Frédéric Kayser - CryoPNG wrote:
> Hello,
> I took a peek at the BGP (Better Portable Graphics) http://bellard.org/bpg/ specs and and it turns out the way transparency was added is not really convincing.
> Could a still image format based on Daala offer something better at this level? Like a fourth component for alpha that would have its own quality settings and that would be really integrated with the other components (no large independent alpha blob recorded beside the main image).
> 
> Cheers
>