openslide-python icon indicating copy to clipboard operation
openslide-python copied to clipboard

read_region from level=0 takes too long

Open reyvateil opened this issue 4 years ago • 3 comments

Context

Issue type (bug report or feature request): bug Operating system (e.g. Fedora 24, Mac OS 10.11, Windows 10): Debian 10 Platform (e.g. 64-bit x86, 32-bit ARM): x86-64 OpenSlide Python version (openslide.__version__): 1.1.2 OpenSlide version (openslide.__library_version__): 3.4.1 Slide format (e.g. SVS, NDPI, MRXS): MRXS

Details

Slides at level=0 are roughly 200,000 x 100,000 pixels. When trying to read_region 512x512 tiles from level=0 every tile takes anywhere between 40s to 2min to read. In contrast, when trying to read 512x512 tiles from level=1 (100,000 x 50,000 px) it only takes less than a second.

Is such a jump in extraction time expected?

reyvateil avatar Oct 13 '20 06:10 reyvateil

No, that isn't expected. If you're still having this problem, please post enough info to allow us to reproduce this, or at least post the relevant section of your Python code.

bgilbert avatar May 29 '22 01:05 bgilbert

Same here. I guess there may be due to the nature of the wsi itself. But not sure what's the problem

RYY0722 avatar Apr 26 '23 08:04 RYY0722

Having similar problems a year later. I am opening the slide, reading the region and saving it as a PNG image. Depending on the slide, it takes between 30 seconds to almost 3 minutes at times. Any suggestions?

sj9515 avatar Jul 23 '24 19:07 sj9515