Hi Bob,
Thanks for the quick response!
We're building libtiff v4.6.0 with libjpeg-turbo v3.0.0. In fact, we worked
extensively with the libjpeg-turbo maintainer to enable lossless support for
8-, 12-, and 16-bit images. And I modified our JPEG source code to work with
the new jpeg12_read_scanlines, jpeg16_read_scanlines, etc. functions in
libjpeg-turbo.
A few things to note that might be clues:
1. Previously in our libjpeg v6b, we had heavily patched it with Ken
Murchison's lossless patch to enable lossless support. But by working with the
libjpeg-turbo maintainer to enable lossless support in libjpeg-turbo, we're now
able to use libjpeg-turbo in place of our heavily patched libjpeg v6b. And
because libjpeg-turbo allows run-time bit depth selection, we're able to use
the same libjpeg-turbo library for the three bit-depths (instead of compiling
it into three different bit-depth-specific libraries).
2.
I didn't do anything special when configuring libtiff v4.6.0 to build with
libjpeg-turbo, other than to make sure I saw the "dual mode" configuration
specification – if I remember correctly when I built libtiff v4.6.0, when it
looked for libjpeg-turbo it made sure some dual mode configuration was set to
enable 8- and 12-bit modes. Is there a config setting I might have missed that
enables working with 16-bit images?
3.
I'm also now building libtiff dynamically with libjpeg-turbo (instead of the
previous static linking with libjpeg v6.b).
4.
In our MATLAB imread test that's failing with the TIFF file that has the
"linearRaw" subIFD, there's a note that even with libtiff built with libjpeg
v6b, it was only able to decode the first 10 tiles of the linearRaw subIFD –
for the rest of the tiles, it was returning uninitialized memory.
Unfortunately the developer who wrote that test is out of office and I don't
know the backstory on where that TIFF file came from, or why libtiff built with
libjpeg v6b was only able to decode the first 10 tiles of the subIFD.
If you think of anything or if i missed a libtiff config setting for reading
16-bit images, please let me know. I'm really puzzled as to what's going on.
I'm also reaching out to the libjpeg-turbo maintainer for help with this.
Thank you!
ellen
________________________________
From: Bob Friesenhahn <[email protected]>
Sent: Monday, February 5, 2024 3:28 PM
To: Ellen Johnson <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: [Tiff] error reading linearRaw subIFD from a TIFF file with
libtiff built with libjpeg-turbo?
On Mon, 5 Feb 2024, Ellen Johnson via Tiff wrote:
> Our imread function successfully reads the main image and the second subIFD.
> But when reading the first subIFD, something goes awry – it ends up calling
> libtiff's TIFFReadTile function in tif_read.c, which then calls
> TIFFReadEncodedTile (also in tif_read.c). I haven't debugged further yet, but
> something fails during TIFFReadEncodedTile which results in our imread
> function give error that the file has no readable tiles.
>
> I'm wondering if you know what may be going wrong here, and/or if
> there are any limitations with libtiff built with libjpeg-turbo that
> would cause problems reading a 16-bit linearRaw subIFD that is JPEG
> compressed.
Until libjpeg-turbo 2.1.5 (see
https://github.com/libjpeg-turbo/libjpeg-turbo/releases)<https://github.com/libjpeg-turbo/libjpeg-turbo/releases)>,
it was not
possible to easily support 16-bit JPEG. Since that version, it is
possible for one library to support 8, 12, and 16-bit JPEG.
Working properly with the above requires a libtiff which operates
correctly with the "new" (re-purposed) API. This would likely mean
that you need a recent libtiff, released since the new libjpeg-turbo
features were added.
What libjpeg-turbo are you using, and how was it configured?
Bob
--
Bob Friesenhahn
[email protected],
http://www.simplesystems.org/users/bfriesen/<http://www.simplesystems.org/users/bfriesen>
GraphicsMagick Maintainer,
http://www.GraphicsMagick.org/<http://www.GraphicsMagick.org>
Public Key,
http://www.simplesystems.org/users/bfriesen/public-key.txt<http://www.simplesystems.org/users/bfriesen/public-key.txt>
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