- 2007.07.03 19:04 "Re: [Tiff] BigTIFF extension?", by Stephen Carlsen
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2007.07.03 19:09 "Re: [Tiff] BigTIFF extension?", by Bob Friesenhahn
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2007.07.04 15:58 "Re: [Tiff] BigTIFF extension?", by Phil Harvey
- 2007.07.04 11:37 "Re: [Tiff] BigTIFF extension?", by Phil Harvey
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2007.07.04 17:13 "[Tiff] 16-Bit-Per-Channel Lossless Compression", by Stephen Carlsen
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2007.07.04 17:24 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
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2007.07.04 17:26 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
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2007.07.04 17:49 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Stephen Carlsen
- 2007.07.04 18:00 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Joris Van Damme
- 2007.07.04 20:37 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
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2007.07.05 10:56 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andrey Kiselev
- 2007.07.05 12:03 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
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2007.07.05 17:58 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Stephen Carlsen
- 2007.07.04 18:02 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Joris Van Damme
- 2007.07.05 18:30 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Joris Van Damme
- 2007.07.06 01:46 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Chris Cox
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2007.07.04 17:49 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Stephen Carlsen
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2007.07.04 17:26 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
- 2007.07.04 17:28 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Michael Wolf
- 2007.07.04 17:36 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andrew Brooks
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2007.07.04 17:24 "Re: [Tiff] 16-Bit-Per-Channel Lossless Compression", by Andy Cave
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2007.07.04 15:58 "Re: [Tiff] BigTIFF extension?", by Phil Harvey
- 2007.07.03 19:17 "Re: [Tiff] BigTIFF extension?", by Andy Cave
- 2007.07.04 11:53 "Re: [Tiff] BigTIFF extension?", by Phil Harvey
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2007.07.04 20:52 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.04 21:04 "Re: [Tiff] BigTIFF extension", by Toby Thain
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2007.07.05 05:07 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 08:09 "Re: [Tiff] BigTIFF extension", by Andy Cave
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2007.07.05 13:40 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 21:00 "Re: [Tiff] BigTIFF extension", by Chris Cox
- 2007.07.05 21:19 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 22:13 "Re: [Tiff] BigTIFF extension", by Bob Friesenhahn
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2007.08.06 22:48 "RE: [Tiff] Transparency ... associated or unassociated alpha is morecompatible?", by Chris Cox
- 2007.08.06 22:32 "RE: [Tiff] Transparency ... associated or unassociated alpha is morecompatible?", by Chris Cox
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2007.08.06 22:48 "RE: [Tiff] Transparency ... associated or unassociated alpha is morecompatible?", by Chris Cox
- 2007.07.06 12:36 "Re: [Tiff] BigTIFF extension", by Gary McGath
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2007.07.05 21:00 "Re: [Tiff] BigTIFF extension", by Chris Cox
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2007.07.05 13:40 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 08:09 "Re: [Tiff] BigTIFF extension", by Andy Cave
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2007.07.05 16:26 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 04:19 "RE: [Tiff] BigTIFF extension", by Kemp Watson
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2007.07.04 16:56 "[Tiff] BigTIFF extension", by Kemp Watson
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2007.07.04 17:35 "Re: [Tiff] BigTIFF extension", by Andrew Brooks
- 2007.07.04 18:13 "Re: [Tiff] BigTIFF extension", by John Aldridge
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2007.07.04 18:25 "Re: [Tiff] BigTIFF extension", by Phil Harvey
- 2007.07.04 18:52 "Re: [Tiff] BigTIFF extension", by Toby Thain
- 2007.07.04 19:17 "Re: [Tiff] BigTIFF extension", by Frank Warmerdam
- 2007.07.05 20:31 "Re: [Tiff] BigTIFF extension", by Chris Cox
- 2007.07.05 15:14 "[Tiff] BigTIFF - Aware Aperio version diff", by Kemp Watson
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2007.07.04 17:35 "Re: [Tiff] BigTIFF extension", by Andrew Brooks
- 2007.07.05 04:54 "RE: [Tiff] BigTIFF extension", by Stephen Carlsen
- 2007.07.05 16:32 "RE: [Tiff] BigTIFF extension", by Kemp Watson
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2007.07.04 16:56 "[Tiff] BigTIFF extension", by Kemp Watson
- 2007.07.05 18:56 "Re: [Tiff] BigTIFF extension", by Toby Thain
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2007.07.05 04:19 "RE: [Tiff] BigTIFF extension", by Kemp Watson
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2007.07.05 05:07 "Re: [Tiff] BigTIFF extension", by Joris Van Damme
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2007.07.05 10:06 "Re: [Tiff] BigTIFF extension", by John Aldridge
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2007.07.05 13:23 "[Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Gary McGath
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2007.07.05 13:56 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Joris Van Damme
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2007.07.05 14:14 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Gary McGath
- 2007.07.05 14:39 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Joris Van Damme
- 2007.07.05 15:26 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Andrey Kiselev
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2007.07.05 14:14 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Gary McGath
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2007.07.05 13:56 "Re: [Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Joris Van Damme
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2007.07.05 13:23 "[Tiff] Re: Tiff Digest, Vol 38, Issue 12", by Gary McGath
- 2007.07.05 16:51 "Re: [Tiff] BigTIFF extension", by Andrew Brooks
- 2007.07.09 16:11 "Re: [Tiff] BigTIFF extension", by Stephen Carlsen
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2007.07.04 21:04 "Re: [Tiff] BigTIFF extension", by Toby Thain
2007.08.06 22:48 "RE: [Tiff] Transparency ... associated or unassociated alpha is morecompatible?", by Chris Cox
Bob;
Yes, I know.
I'd like to have some way to specify un-premultiplied/unmatted transparency, but it would be a major change to TIFF. (adding new alpha channel types helps, but it would require changes to a lot of software before it would work correctly)
"Correct according to the original Targa specifications" and "what most users of the TGA format expect and understand" are completely different things... Photoshop tries to follow the format specs., but sometimes users don't follow the specs, much less understand the specs.
Chris
Cc: Tiff List
Subject: RE: [Tiff] Transparency... associated or unassociated alpha is morecompatible?
On Mon, 6 Aug 2007, Chris Cox wrote:
> PNG and SGI RGB support associated alpha (aka transparency), just not premultiplied.
Thanks for correcting my wrong use of terms. It is a pity that TIFF
does not provide a way to specify associated alpha which is not
premultiplied.
> TGA is supposed to support associated alpha (transparency), but most
> users of TGA don't seem to understand the difference and get
> transparency and general (unassociated) alpha channels confused.
> When Photoshop 7 shipped with transparency support in TGA format,
> the users got so confused that Adobe had to go back to using
> unassociated alpha. The TGA users still can't agree on what they
> want, much less what they understand.
That is interesting to know. As far as I am aware, GraphicsMagick
handles alpha correctly (according to written specification) for TGA
files. I spent quite a bit of time double checking it and fixing
things.
Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/