ValueError: not enough values to unpack (expected 3, got 2)

[Doloresru]

When i use the Python package the same as the given demo ,I met a error as:
File "E:/Pycharm project/maching learning/HW2/Try.py", line 10, in
cnts,d_factor = tl.locate_tissue_cnts(slide_path,max_img_size=2048,smooth_sigma=13,thresh_val=0.80,min_tissue_size=10000)
File "C:\Users\17807\AppData\Roaming\Python\Python37\site-packages\tissueloc\locate_tissue.py", line 146, in locate_tissue_cnts
cnts = find_tissue_cnts(bw_remove)
File "C:\Users\17807\AppData\Roaming\Python\Python37\site-packages\tissueloc\locate_tissue.py", line 103, in find_tissue_cnts
method=cv2.CHAIN_APPROX_NONE)
ValueError: not enough values to unpack (expected 3, got 2)

How can I solve this error? thanks first!

[PingjunChen]

I believe the reason should be the version of OpenCV. The output parameters of cv2.findContours is changed. Please use the version specified in the requirements, namely opencv-python==3.4.4.19.

Sorry for the late reply.

[PingjunChen]

Thanks for the question. The package now is updated to version 2.1.0, which uses OpenCV-4.1.2.30, in which two values would return from function findContours instead of three in OpenCV-3.xx. I believe your problem would be resolved using OpenCV-4.xx and tissueloc-2.1.0.