`slide_thumbnail` method does not work properly with DICOM WSIs

[mostafajahanifar]

• TIA Toolbox version: 1.3
• Python version: 3.10
• Operating System: Ubuntu

Description

When reading a DICOM slide and trying to use slide_thumbnail to get the slide thumbnail at a certain resolution, it does not work properly and instead of giving the slide thumbnail, it returns a region of the slide which seems to be extracted from the baseline resolution.

What I Did

wsi = WSIReader('path_to_sample.dicom')
thumb = wsi.slide_thumnail(resolution=8, units='mpp')

p.s.
I checked the same slide with wsidicom library and the slide_thumbnail of that library works just fine.

[mostafajahanifar]

[update]

I just checked this on Windows OS as well with TIAToolbox v1.3.3, and the same problem persists. Can anyone else try it, please?
There might be something wrong with my installation or the file I'm using.

[measty]

I tried it on windows, had the same result (got a region that looks like its at base resolution). Using the CMU-1.dicom sample from tiatoolbox remote_samples

[measty]

I made a PR that maybe fixes this (my knowledge of DICOM isnt good enough for me to be sure, but seems to work). #564