ValueError: Argument is not writable

[tnnandi]

Operating system

Ubuntu

Platform

64 bit x86

OpenSlide Python version

1.3.1

OpenSlide version

4.0.0

Slide format

SVS

Issue details

Hi,

When I try to use the read_region function as follows:
level = slide.get_best_level_for_downsample(32)
region = slide.read_region((0, 0), level, slide.level_dimensions[level])

I get the following error:
region = slide.read_region((0, 0), level, slide.level_dimensions[level])
*** ValueError: Argument is not writable

I'd appreciate it if you could suggest a solution.

Thanks

[bgilbert]

I can't reproduce this behavior:

$ cat test.py 
import openslide
slide = openslide.OpenSlide('Aperio/CMU-1.svs')
level = slide.get_best_level_for_downsample(32)
region = slide.read_region((0, 0), level, slide.level_dimensions[level])
print(region)
$ python test.py 
<PIL.Image.Image image mode=RGBA size=2875x2057 at 0x7EFFF1440E00>

Can you provide any more details that would help reproduce it?

[tnnandi]

Thanks for your input! I think the issue was tied to the pillow version. With Pillow 10.1.0, I was encountering another issue related to the ANTIALIAS attribute of PIL.image, and I had to downgrade the Pillow version to 9.5.0 to get around both.

[bgilbert]

Hmm, okay. I've now tried with both Pillow 9.5.0 and 10.1.0 and still cannot reproduce this. Can you provide any more information, such as a full backtrace for the ValueError? How did you install OpenSlide and OpenSlide Python?