POV-Ray : Newsgroups : povray.programming : Is this a bug? Server Time
19 Apr 2024 00:45:13 EDT (-0400)
  Is this a bug? (Message 1 to 4 of 4)  
From: Anthony D  Baye
Subject: Is this a bug?
Date: 8 May 2007 15:15:01
Message: <web.4640cb2fed94f1b46de1e3230@news.povray.org>
I think I've discovered a bug in the output of Targa files under windows XP.

I'm currently writing a small command line utility to work with .tga files
created in POV, and I've been trying to test some of the lower-level
functions by having it print out a list of files in a given directory and
show the type-code (2 or 10 for POV output) their bit-depth, and
resolution.

The documentation states that I can force POV to output targa files by using
the command line flag +Fxn, so I've been trying it with +FT8, +FT16, +FT24,
and +FT32, but no matter what depth I specify, POV always outputs a 24-bit
targa file.

I tried creating other bit-depths in Photoshop, and those work fine.  Also,
the 32-bit (w/ alpha channel) render I ported over from my Macintosh reads
the correct depth.

Any input you can provide on this matter will be greatly appreciated.

Regards,

ADB


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From: Warp
Subject: Re: Is this a bug?
Date: 8 May 2007 15:55:43
Message: <4640d5bf@news.povray.org>
Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> The documentation states that I can force POV to output targa files by using
> the command line flag +Fxn, so I've been trying it with +FT8, +FT16, +FT24,
> and +FT32, but no matter what depth I specify, POV always outputs a 24-bit
> targa file.

  Actually the documentation only mentions PNG and PPM as supporting bit
depths other than 24 bpp:

"Most of these formats output 24 bits per pixel with 8 bits for each
of red, green and blue data. PNG and PPM allow you to optionally
specify the output bit depth from 5 to 16 bits for each of the red,
green, and blue colors, giving from 15 to 48 bits of color information
per pixel. The default output depth for all formats is 8 bits/color
(16 million possible colors), but this may be changed for PNG and PPM
format files by setting Bits_Per_Color=n or by specifying +FNn or
+FPn, where n is the desired bit depth."

-- 
                                                          - Warp


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From: Anthony D  Baye
Subject: Re: Is this a bug?
Date: 8 May 2007 17:05:02
Message: <web.4640e5bbc0eb7a166de1e3230@news.povray.org>
Warp <war### [at] tagpovrayorg> wrote:
>   Actually the documentation only mentions PNG and PPM as supporting bit
> depths other than 24 bpp:
>
> "Most of these formats output 24 bits per pixel with 8 bits for each
> of red, green and blue data. PNG and PPM allow you to optionally
> specify the output bit depth from 5 to 16 bits for each of the red,
> green, and blue colors, giving from 15 to 48 bits of color information
> per pixel. The default output depth for all formats is 8 bits/color
> (16 million possible colors), but this may be changed for PNG and PPM
> format files by setting Bits_Per_Color=n or by specifying +FNn or
> +FPn, where n is the desired bit depth."
>
> --
>                                                           - Warp

Alright.  I was wondering because one of the renders I brought over from my
Mac is  32-bit, but it's also type 10, rather than type 2, which means that
it's also Run-length encoded (I suspect the difference has to do with an
alpha-channel)

Regards,

ADB


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From: Thorsten Froehlich
Subject: Re: Is this a bug?
Date: 8 May 2007 18:46:52
Message: <4640fddc$1@news.povray.org>
Anthony D. Baye wrote:
> Alright.  I was wondering because one of the renders I brought over from my
> Mac is  32-bit, but it's also type 10, rather than type 2, which means that
> it's also Run-length encoded (I suspect the difference has to do with an
> alpha-channel)

No, it has to do with the "compression" setting on the Mac side. POV-Ray can
do RLE and regular Targa iirc.

	Thorsten


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