<flame>
Why can't Photoshop get PNG files right?  Not only does it seem to have no
way to view my palette when I'm editing a "indexed color" image, but when I
save as PNG, it saves as a 8-bit/sample RGB file!  Isn't that kind of
missing the point?!
</flame>

What tool (running under Windows NT) can I use to find out what palette I
ended up with in a GIF file?  That is, I need to know which color index is
which RGB value, so I can set up my "transmit" modifiers properly in the
image_map statement.

Better yet, how can I put them in the order I want in the first place, so I
don't have to re-do it every time I edit the file?

Do I need to write a BMP/TGA to PNG converter that takes an optional palette
file as input to guide the conversion, or does something like that already
exist?

--John

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I haven't use paletted images for awhile, but with paint shop pro you can edit
the palette and read what colors are assigned to which index.  You can even load
a palette you would like to use.  It'll save PNG images to 256 colors too.

demoville is www.jasc.com

-Mike

John M. Dlugosz wrote:

> <flame>
> Why can't Photoshop get PNG files right?  Not only does it seem to have no
> way to view my palette when I'm editing a "indexed color" image, but when I
> save as PNG, it saves as a 8-bit/sample RGB file!  Isn't that kind of
> missing the point?!
> </flame>
>
> What tool (running under Windows NT) can I use to find out what palette I
> ended up with in a GIF file?  That is, I need to know which color index is
> which RGB value, so I can set up my "transmit" modifiers properly in the
> image_map statement.
>
> Better yet, how can I put them in the order I want in the first place, so I
> don't have to re-do it every time I edit the file?
>
> Do I need to write a BMP/TGA to PNG converter that takes an optional palette
> file as input to guide the conversion, or does something like that already
> exist?
>
> --John

Post a reply to this message

><flame>
>Why can't Photoshop get PNG files right?  Not only does it seem to have no
>way to view my palette when I'm editing a "indexed color" image, but when I
>save as PNG, it saves as a 8-bit/sample RGB file!  Isn't that kind of
>missing the point?!
></flame>


Have you had a look at the help files? What version are you using? Mine
(5.5) does this (saving) just fine, and I can see the palette any time I
want.

>What tool (running under Windows NT) can I use to find out what palette I
>ended up with in a GIF file?  That is, I need to know which color index is
>which RGB value, so I can set up my "transmit" modifiers properly in the
>image_map statement.

Have you tried "exporting" it as a GIF instead of saving it as a GIF after
color reduction?

>Better yet, how can I put them in the order I want in the first place, so I
>don't have to re-do it every time I edit the file?

You've got me there. I know of a BMP utility for making startup screens that
allows this, but no other program. You can also save the palette and use it
for other images later on.

>Do I need to write a BMP/TGA to PNG converter that takes an optional
palette
>file as input to guide the conversion, or does something like that already
>exist?


The more the merrier...

Post a reply to this message

The Gimp, for NT look at:
http://www.gimp.org/~tml/gimp/win32/

Ingo

John M. Dlugosz <joh### [at] dlugoszcom> schreef in berichtnieuws
37e5a9df@news.povray.org...
> What tool (running under Windows NT) can I use to find out what
palette I
> ended up with in a GIF file?  That is, I need to know which color
index is
> which RGB value, so I can set up my "transmit" modifiers properly in
the
> image_map statement.
>
> Better yet, how can I put them in the order I want in the first place,
so I
> don't have to re-do it every time I edit the file?
>
> Do I need to write a BMP/TGA to PNG converter that takes an optional
palette
> file as input to guide the conversion, or does something like that
already
> exist?
>
> --John
>

Post a reply to this message

Mike <pov### [at] aolcom> wrote in message news:37E5AA0C.85AFFA82@aol.com...
> I haven't use paletted images for awhile, but with paint shop pro you can
edit
> the palette and read what colors are assigned to which index.  You can
even load
> a palette you would like to use.  It'll save PNG images to 256 colors too.

I've not touched PSP in a long time, either.  Their newer version added more
serious features, but also changed things so I no longer knew how to operate
it.  Meanwhile, it chokes when I print large images, so I gave up using it
even for light duity work.

So, if you don't use paletted images, what do you use for POV image maps?
Photoshop refuses to save as anything other than native format if the image
has transparant patches <sigh>.

--John

Post a reply to this message

TonyB <ben### [at] panamaphoenixnet> wrote in message
news:37e619f6@news.povray.org...
> Have you had a look at the help files? What version are you using? Mine
> (5.5) does this (saving) just fine, and I can see the palette any time I
> want.

Thanks -- I'm using 5.0.2, and could not find any interesting new features
in their brocure to intice me to spend three figures to upgrade =again=.  I
suppose these details, which were not mentioned, comes under the general
category of "better for Web images".

So how do you view the palette?  Maybe I just missed it.

> Have you tried "exporting" it as a GIF instead of saving it as a GIF after
> color reduction?

It doesn't make any difference -- that is, it doesn't prompt me to use a
defined palette.

> You've got me there. I know of a BMP utility for making startup screens
that
> allows this, but no other program. You can also save the palette and use
it
> for other images later on.

I'm thinking it would be comparitivly simple to write a utility to modify
the palette in a PNG file, since it doesn't require decoding/reencoding the
image data at all.  Have a simple program that will find the pallette entry
with the specified RGB values, and add an Alpha to it, or otherwise change
the entry to whatever you like.  Then you can paint with special key colors
not otherwise found in the image, and then run this tool.  If POV respects
Alpha in paletted PNG's, it wouldn't matter which index it was, as the info
would be entirely contained within the image.

FWIW, I suspect that "export as GIF" in Photshop builds the palette in the
order in which it sees the colors, so the "background" color is probably
index 0.  I've not tested that in detail, though.


--John

Post a reply to this message

> I've not touched PSP in a long time, either.  Their newer version added more
> serious features, but also changed things so I no longer knew how to operate
> it.  Meanwhile, it chokes when I print large images, so I gave up using it
> even for light duity work.

I still use version 5 almost daily for things like screen capture, browsing, and
batch conversion.  I don't use it much for detail work or, like you mention,
large images because it isn't all that efficient with memory.  It also doesn't
save alpha channels with images for some strange reason.

> So, if you don't use paletted images, what do you use for POV image maps?
> Photoshop refuses to save as anything other than native format if the image
> has transparant patches <sigh>.

I tend to stick with alpha channels for specifying transparency since it's alot
less work and you can get smooth results that way.  I will still use GIF images
and the filter all keyword when I want specific filtering effects like stained
glass.  The docs say you can have different transparency levels set for each
color in a paletted PNG image, but nothing I have supports that (I use
photopaint and PSP).

So, in short, I pretty much stick to 32-bit targa or PNG images with alpha
channels for 99% of my image mapping.

-Mike

Post a reply to this message

Mike wrote:
> I still use version 5 almost daily for things like screen capture, browsing, and
> batch conversion.  I don't use it much for detail work or, like you mention,
> large images because it isn't all that efficient with memory.  It also doesn't
> save alpha channels with images for some strange reason.
[snip]
> glass.  The docs say you can have different transparency levels set for each
> color in a paletted PNG image, but nothing I have supports that (I use
> photopaint and PSP).

Really? I have PSP 5 also, and it both saves alpha channels and does
paletted PNG images. And I upgraded shortly after that version came
out, so mine is still one of the earliest releases. Maybe you've got 
a buggy intermediate version? (I hate when they start fiddling to 
try and "fix" stuff...) Just to make sure it wasn't some
inconsistency between the PNG support of POV and PSP, I just tried 
a test both ways, and both paletted PNG and alpha channel info 
exported by PSP seems to work fine in POV image_maps. 

Charles
-- 
http://www.enter.net/~cfusner
"...Then darkness took me, and I strayed out of thought and time,
 and I wandered far on roads that I will not tell..." 
                              -The Two Towers, JRR Tolkien

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Mike <pov### [at] aolcom> wrote in message news:37E6FC4B.8185541D@aol.com...

> So, in short, I pretty much stick to 32-bit targa or PNG images with alpha
> channels for 99% of my image mapping.

Using Paint Shop Pro to create?

Post a reply to this message

> Really? I have PSP 5 also, and it both saves alpha channels and does
> paletted PNG images. And I upgraded shortly after that version came
> out, so mine is still one of the earliest releases. Maybe you've got
> a buggy intermediate version? (I hate when they start fiddling to
> try and "fix" stuff...)

I figured it was fixed in an update, but I just haven't gotten around to updating
mine.  I bought it right after it came out, so it's possible there are bugs in what
I'm using.

-Mike

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