Not sure about your particular file, but we extract hundreds of thousands of 
YCbCr JPEG images from TIFFs every day...

W. Kemp Watson
Objective Pathology Services
Toronto,  Canada

http://www.objectivepathology.com

[email protected]
tel. +1 (647) 783-4431

> On May 21, 2022, at 3:37 PM, L. E. Segovia via Tiff <[email protected]> 
> wrote:
> 
> Hi all,
> 
> Recently one of my colleagues at Krita found an abandoned TIFF in our source 
> code repository that, to the best of our knowledge, had never been checked 
> into our test suite.
> 
> Turns out, it is a JPEG-compressed, YCbCr TIFF. I've recently added color 
> space profiles for YCbCr, but when loading this sample inside our app, the 
> output shows significant corruption as well as misaligned strips.
> 
> I've tried the tiff2rgba and rgba2ycbcr tools to generate copies, and can 
> confirm that:
> 
> - Loading YCbCr TIFFs with anything but JPEG compression works.
> - Loading RGBA TIFFs with any compression, including JPEG, works.
> 
> which leads me to conclude that the expected layout of YCbCr + JPEG doesn't 
> match what it says on the tin ("Ordering of Component Samples", page 93 of 
> the standard). Unfortunately, I can't verify my suspicions with libtiff's 
> source code itself, as in all cases, either the data is already in RGB form 
> or libjpeg-turbo is asked to convert it to RGB.
> 
> Does anyone know what the layout of this kind of data is? Or, alternatively, 
> where I could start looking?
> 
> Best,
> 
> amyspark
> 
> -- 
> amyspark 🌸 https://www.amyspark.me
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