NotImplementedError: unsupported filter /RunLengthDecode

[stefan6419846]

Explanation

The RunLengthDecode filter does not seem to be implemented.

It seems like a corresponding example file is very easy to create by just running ImageMagick on a PDF file of your choice: convert -density 300 -units PixelsPerInch test_document.pdf -alpha off out.pdf (example: out.pdf)

Code Example

reader = PdfReader('tmp/out.pdf')
page = reader.pages[0]
for image in page.images:
    print(image)

Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/home/user/lib/python3.9/site-packages/pypdf/_page.py", line 2604, in __iter__
    yield self[i]
  File "/home/user/lib/python3.9/site-packages/pypdf/_page.py", line 2600, in __getitem__
    return self.get_function(lst[index])
  File "/home/user/lib/python3.9/site-packages/pypdf/_page.py", line 522, in _get_image
    imgd = _xobj_to_image(cast(DictionaryObject, xobjs[id]))
  File "/home/user/lib/python3.9/site-packages/pypdf/filters.py", line 854, in _xobj_to_image
    data = x_object_obj.get_data()  # type: ignore
  File "/home/user/lib/python3.9/site-packages/pypdf/generic/_data_structures.py", line 956, in get_data
    decoded._data = decode_stream_data(self)
  File "/home/user/lib/python3.9/site-packages/pypdf/filters.py", line 634, in decode_stream_data
    raise NotImplementedError(f"unsupported filter {filter_type}")
NotImplementedError: unsupported filter /RunLengthDecode

[pubpub-zz]

to force RunLengthDecode you should add -compress RLE
however thanks for report and test set:
the image (for test):

[pubpub-zz]

@stefan6419846 PR is available if you want to test it

[stefan6419846]

@pubpub-zz Just did a quick test with my original failing file and it seems to work correctly. Thanks.