[gdal-dev] Giventiff with colortable, how do i assign one of the colors to be an alpha channel

[Isaac Gerg]

To be clear, suppose I want to make the red bow in the image below as a
tiff file with transparency. But instead of using RGBA, can tiff create it
with indexed color?

http://d241yswl6yg9sc.cloudfront.net/remove-background2/4.png

Isaac


On Wed, Jan 16, 2013 at 3:40 PM, Isaac Gerg <isaac.gerg at gergltd.com> wrote:

> Even,
>
> I am confused.  You said in your first response to me that TIFF does not
> support indexed colormaps of RGBA. Am I understanding you correctly -- it
> sounds like it is not possible to create an indexed color TIFF that has
> background transparency.  Is this correct?
>
> Isaac
>
>
> On Wed, Jan 16, 2013 at 3:23 PM, Even Rouault <
> even.rouault at mines-paris.org> wrote:
>
>> Le mercredi 16 janvier 2013 21:21:29, Isaac Gerg a écrit :
>> > I mispoke.
>> >
>> > rgb2pct.py will work but only on RGB images -- no colortables.  When I
>> use
>> > it on a RGBA image, the transparency is no longer preservered.
>>
>> Combine it with the first hints I gave
>>
>
>
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