MacOSでtorchvisionのimportエラー

現象

torchvisionを読み込むと、libpngとか、libjpegのエラーが出る人向け。

import torchvision
/Users/<USER NAME>/.pyenv/versions/py38-test2/lib/python3.8/site-packages/torchvision/io/image.py:11: UserWarning: Failed to load image Python extension: dlopen(/Users/<USER NAME>/.pyenv/versions/3.8.12/envs/py38-test2/lib/python3.8/site-packages/torchvision/image.so, 0x0006): Library not loaded: @rpath/libpng16.16.dylib
  Referenced from: /Users/<USER NAME>/.pyenv/versions/3.8.12/envs/py38-test2/lib/python3.8/site-packages/torchvision/image.so
  Reason: tried: '/usr/local/lib/libpng16.16.dylib' (no such file), '/usr/lib/libpng16.16.dylib' (no such file)
  warn(f"Failed to load image Python extension: {e}")

対策

/usr/local/lib/の下にシンボリックリンクを作成する。

sudo ln -s /opt/homebrew/Cellar/libpng/1.6.37/lib/libpng16.16.dylib /usr/local/lib/libpng16.16.dylib
sudo ln -s /opt/homebrew/Cellar/jpeg/9e/lib/libjpeg.9.dylib /usr/local/lib/libjpeg.9.dylib