AWARE [SYSTEMS]
AWare Systems, , Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
April 2012

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
Archive maintained by AWare Systems



New Datamatrix section



Valid HTML 4.01!



Thread

2012.04.24 16:26 "YCbCr/JPEG issue in 4.0.1", by John Evans
2012.04.24 16:44 "Re: YCbCr/JPEG issue in 4.0.1", by Frank Warmerdam
2012.04.24 19:03 "Re: YCbCr/JPEG issue in 4.0.1", by John Evans
2012.04.24 19:19 "Re: YCbCr/JPEG issue in 4.0.1", by Even Rouault
2012.04.27 15:35 "Re: YCbCr/JPEG issue in 4.0.1", by Charles Auer
2012.04.27 17:07 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme
2012.04.27 18:57 "Re: YCbCr/JPEG issue in 4.0.1", by John Evans
2012.04.28 01:58 "Re: YCbCr/JPEG issue in 4.0.1", by Charles Auer
2012.05.02 09:51 "Re: YCbCr/JPEG issue in 4.0.1", by Charles Auer
2012.05.03 21:58 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme
2012.04.28 09:28 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme
2012.04.28 09:46 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme
2012.04.28 15:10 "Re: YCbCr/JPEG issue in 4.0.1", by Charles Auer
2012.04.28 16:26 "Re: =?windows-1256?q?YCbCr/JPEG_issue_in_4=2E0=2E1=FE?=", by Charles Auer
2012.05.01 12:52 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme

2012.04.28 09:28 "Re: YCbCr/JPEG issue in 4.0.1", by Joris Van Damme

Charles,

> Yes, I confess, I am one of those lazy JPEGCOLORMODE = 1 people.

I don't agree with the term 'lazy'. It boils down to bad library
design, rather then lazy library usage.

As YCbCr can be combined with any compression mode, and subsampling
can be combined with one/some/all colorspaces depending on your point
of view, and any compression mode, it's actually the TIFF container
codec that should be responsible for subsampling/desubsampling, and
the TIFF RGBA interface part that should be responsible for converting
from RGB to YCbCr and the other way around, rather then partly
delegating the task to a particular subcodec and failing to support
combinations with other subcodecs, and/or partly delegating the task
to the TIFF library user.

Actually, encoding/decoding TIFF should be viewed as a pipeline. TIFF
is not Thousands of Incompatible File Formats, because rather then
providing support for all possible combinations, the codec ought to
freely chain independent support for different features. Subsampling
and desubsampling, as well as color conversions, are simply parts of
the chained pipeline of freely combinable features, and should be
supported as such, independently of other features such as a
particular compression or decompression. That's how TIFF is more like
5+5+5+5+5 = a manageable number of combinable features, rather then
5*5*5*5*5 = an unfeasible number of incompatible formats. This concept
should be at the heart of any TIFF codec. All required support for
subsampling and desubsampling as well as any color conversions, is
merely part of this.


Best regards,

Joris