make pytorch-fid package optional

Author: lucidrains

README.md

@@ -236,6 +236,14 @@ Notes:
 
 Thanks to <a href="https://github.com/GetsEclectic">GetsEclectic</a>, you can now calculate the FID score periodically! Again, made super simple with one extra argument, as shown below.
 
+Firstly, install the `pytorch_fid` package
+
+```bash
+$ pip install pytorch-fid
+```
+
+Followed by
+
 ```bash
 $ stylegan2_pytorch --data ./data --calculate-fid-every 5000
 ```

setup.py

@@ -32,7 +32,6 @@
       'torch',
       'torchvision',
       'pillow',
-      'pytorch-fid',
       'vector-quantize-pytorch>=0.1.0'
   ],
   classifiers=[

stylegan2_pytorch/stylegan2_pytorch.py

@@ -30,8 +30,6 @@
 from stylegan2_pytorch.version import __version__
 from stylegan2_pytorch.diff_augment import DiffAugment
 
-from pytorch_fid import fid_score
-
 from vector_quantize_pytorch import VectorQuantize
 from linear_attention_transformer import ImageLinearAttention
 
@@ -1102,6 +1100,7 @@ def tile(a, dim, n_tile):
 
     @torch.no_grad()
     def calculate_fid(self, num_batches):
+        from pytorch_fid import fid_score
         torch.cuda.empty_cache()
 
         real_path = str(self.results_dir / self.name / 'fid_real') + '/'

stylegan2_pytorch/version.py

@@ -1 +1 @@
-__version__ = '1.5.4'
+__version__ = '1.5.5'