image resize: unsupported gap

Hello, I have a question about a discrepancy between the docs and the actual package. I want to use image resize with sending optional gap as it is referred to in docs, but it crashes with an error…

Package: 2.2.0 (from conda) Docs: https://libvips.github.io/pyvips/vimage.html?highlight=resize#pyvips.Image.resize Code:

img = pyvips.Image.new_from_file(img_path).resize(0.05, gap=2.0).numpy()

Output:

opt/conda/lib/python3.7/site-packages/pyvips/vimage.py in call_function(*args, **kwargs)
   1345         @_add_doc(name)
   1346         def call_function(*args, **kwargs):
-> 1347             return pyvips.Operation.call(name, self, *args, **kwargs)
   1348 
   1349         return call_function

/opt/conda/lib/python3.7/site-packages/pyvips/voperation.py in call(operation_name, *args, **kwargs)
    287                     name not in intro.optional_output):
    288                 raise Error('{0} does not support optional argument {1}'
--> 289                             .format(operation_name, name))
    290 
    291             value = kwargs[name]

Error: resize does not support optional argument gap

[kleisauke]

I commented on https://github.com/conda-forge/pyvips-feedstock/pull/24#issuecomment-1193322009 to mention that pyvips should be backward compatible with older libvipses. Hopefully they will update it to v2.2.1.

[jcupitt]

The python wrapper is (largely) generated at runtime, so the API you get is the API of the underlying libvips binary. Just drop in the libvips.so for 8.13 and you should get the new API.

The thumbnail operation knows about the various WSI formats and will pick the fastest resize method for you. For example, on this seven year old laptop:

john@kiwi:~/pics/openslide$ vipsheader CMU-3.mrxs 
CMU-3.mrxs: 109240x220696 uchar, 4 bands, srgb, openslideload
john@kiwi:~/pics/openslide$ time vipsthumbnail CMU-3.mrxs --size 2000

real	0m0.875s
user	0m1.036s
sys	0m0.075s
john@kiwi:~/pics/openslide$ vipsheader tn_CMU-3.jpg 
tn_CMU-3.jpg: 990x2000 uchar, 3 bands, srgb, jpegload

Or in python:

image = pyvips.Image.thumbnail("CMU-3.mrxs", 2000)
image.write_to_file("thumb.jpg")