[Openexr-devel] newbie questions: alpha-only files and linear conversion on save

[Paul Miller]

Hi guys. I'm adding EXR support to our up-coming cross-platform rotoscoping 
system (Silhouette Roto).

I have two questions:

1) what is the proper way to set up the header for an "alpha-only" image?

2) when saving generic linear color data (ie. 0-255), is it sufficient to 
just normalize to 0-1 and stuff the components into the output half types? 
This seems to work ok when reading the image back in, as long as I adjust 
the gamma to 1.0. If I should apply the output gamma correction, can 
someone post a code snippet?

Thanks!