AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

2017.05.27 15:03 "Re: [Tiff] Unassociated alpha channel", by Aaron Boxer

Note: Perhaps the problem is with my image viewer, which can't handle the opacity in the TIFF file?

On Sat, May 27, 2017 at 11:01 AM, Aaron Boxer <boxerab@gmail.com> wrote:

> Hi Folks,

>
> I have a JPEG 2000 image with unassociated alpha channel.
>
> When I decompress to TIFF using my JP2 library, I set the

> EXTRASAMPLE_UNASSALPHA flag for this channel. The resulting image is a > black M with black background.

>
> If I force the tag to EXTRASAMPLE_ASSOCALPHA, I get a white background.
>

> I've attached the three files. The file with unassociated alpha looks odd > to me. So, I wanted to verify that libtiff handles unassociated alpha

> channels without any knows problems.
>
> Thanks!
>
> Aaron
>
>