NotImplementedError: lzw_encode

Hi there, I’m trying to write a multi page tiff file, like this

with tifffile.TiffWriter("nyname.tif", append=True) as P: P.write(**this_page_dict)

where the dict is:

{
'extratags': [(274, 3, 1, 1), (339, 3, 1, 1), (285, 2, 25, b'myTitle')], 
'bitspersample': 16,
'compression': 5, 
'photometric': 1, 
'rowsperstrip': 8, 
'planarconfig': 1, 
'resolution': (1677721600, 16777216), 
'data': array(..., dtype=uint16), 
'dtype': dtype('uint16')
}

It’s giving me a NotImplemented error, since I’m using compression=5 (LZW).

Traceback (most recent call last): File “…filename.py”, line 122, in <module> P.write(**this_page_dict) File “…\venv\lib\site-packages\tifffile\tifffile.py”, line 2342, in write strip = compress(strip) File “imagecodecs_imcd.pyx”, line 856, in imagecodecs._imcd.lzw_encode NotImplementedError: lzw_encode

Any pointer as of why and maybe how to “solve” / work around this?

[cookmscott]

Hi @cgohlke , would you suggest using @noobOriented’s work around? If so, I’m not quite sure how to implement that for LZW compression if you could include some notes 🙏

Also for sake of clarity, if imagecodecs is not ready to support LZW encoding, could we update the docs here and here to mention you can only decode with LZW via imagecodecs? Maybe imagecodecs will inlcude LZW soon (seems to be the case) and that’s why this request is still open. Thank you!

[cgohlke]

Fixed in imagecodecs 2022.7.27.