ValueError: level not present in slide

[jasnei]

Hi

I'm ready your paper SliDL: Atoolbox for processing whole-slide images in deep learning. just want to do a annotation extraction.

Just simple copy & past from your example notebook 'slidl-tutorial.ipynb, following is the code. Same slide name from CAMELYON16 as your mentioned in the notebook. actually I just want to try the extraction of tile from annotation. but it would let me .

from slidl.slide import Slide
tile_size = 512
fp = 'CAMELYON16/training/tumor/tumor_044.tif'
slide = Slide(fp, level=0, verbose=True)
slide.setTileProperties(tileSize=512, tileOverlap=0, unit='px')
slide.addAnnotations(fp[:-3] + 'xml', negativeClass='negative')
slide.extractAnnotationTiles('data/CMU-1_slidl')

and I got following issue, I think I set all level to all the method, but still cannot fix this issue.

[SliDL] Loading /mnt/f/BaiduNetdiskDownload/CAMELYON16/training/tumor/tumor_044.tif
[SliDL] Successfully loaded
Warning: 'vips-loader' not present in slide properties; verify independently that slide has loaded properly.
[SliDL] 0 properties were successfully imported
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[50], line 1
----> 1 slide.addAnnotations(fp[:-3] + 'xml', negativeClass='negative')

File ~/anaconda3/envs/histo/lib/python3.9/site-packages/slidl/slide.py:636, in Slide.addAnnotations(self, annotationFilePath, classesToAdd, negativeClass, level, overwriteExistingAnnotations, mergeOverlappingAnnotationsOfSameClass, acceptMultiPolygonAnnotations)
    634     raise ValueError('level must be an integer 0 or greater')
    635 if 'openslide.level['+str(level)+'].downsample' not in self.slideProperties:
--> 636     raise ValueError('level not present in slide')
    637 if (classesToAdd) and (not isinstance(classesToAdd, list)):
    638     raise ValueError("classestoAdd must a list")

ValueError: level not present in slide

According to the verbose messege, i try following code, and I got a [], it should be the slide not read properly by the vips, however, I could get the thumbnail properly.

slide.slide.get_fields()

Please advise how could I fix this issue

Thanks
Albert