[ptx] nona, gimp-2, TIFF_mask multilater tiff files

[Ed Halley]

On Wed, 2004-01-07 at 08:01, Bruno Postle wrote:
> gimp-2 pre1 has just been released, and according to the release
> notes it has "Support for multipage TIFFs [Andrey Kiselev]".
> 
> I thought I would try it with the nona TIFF_mask output.
> 
> The file loads but with a couple of problems:
> 
> -  All file offsets are ignored, each layer is fitted to the top
>    left corner and the overall image is resized to the dimensions of
>    the first layer.  This is not so bad, it just means that the
>    image needs to be resized and the layers dragged to fit.
> 
> -  The masks are loaded as alpha-channels with no pixel information
>    remaining in the fully transparent areas, so there is no way to
>    blend the images by hand as there would be if the masks were
>    loaded as layer masks.

I was afraid of that.  If the same notes were added to bug 66886
http://bugzilla.gnome.org/show_bug.cgi?id=66886 then we may be able to
get Sven to support these extra details before it's finalized.  I put in
a searchable comment on that bug, but haven't run the CVS version. 

However, not having seen either version of the TIFF code, how does the
tiff loader know which images are meant as masks and which are meant as
layers?  To tiff, they're just images, right?  Maybe any single-channel
image is a mask, when it follows/precedes a like-sized multi-channel
image?

-- 
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