diff --git a/codes/trainer/eval/sr_diffusion_fid.py b/codes/trainer/eval/sr_diffusion_fid.py
index 7730f8cb..eba49cd7 100644
--- a/codes/trainer/eval/sr_diffusion_fid.py
+++ b/codes/trainer/eval/sr_diffusion_fid.py
@@ -50,8 +50,8 @@ class SrDiffusionFidEvaluator(evaluator.Evaluator):
                 torch.distributed.all_gather(gather_list, gen)
                 gen = torch.cat(gather_list, dim=0)
 
-            for b in range(self.batch_sz):
-                torchvision.utils.save_image(gen[b], osp.join(fid_fake_path, "%i_.png" % (counter)))
+            for g in gen:
+                torchvision.utils.save_image(g, osp.join(fid_fake_path, f"{counter}.png"))
                 counter += 1
 
         return {"fid": fid_score.calculate_fid_given_paths([self.fid_real_samples, fid_fake_path], self.fid_batch_size,