Fix a batch dim issue in resize_with_pad_torch

src/openpi/shared/image_tools.py

@@ -71,16 +71,19 @@ def resize_with_pad_torch(
         Resized and padded tensor with same shape format as input
     """
     # Check if input is in channels-last format [*b, h, w, c] or channels-first [*b, c, h, w]
+    batch_dim_added = False
     if images.shape[-1] <= 4:  # Assume channels-last format
         channels_last = True
         # Convert to channels-first for torch operations
         if images.dim() == 3:
             images = images.unsqueeze(0)  # Add batch dimension
+            batch_dim_added = True
         images = images.permute(0, 3, 1, 2)  # [b, h, w, c] -> [b, c, h, w]
     else:
         channels_last = False
         if images.dim() == 3:
             images = images.unsqueeze(0)  # Add batch dimension
+            batch_dim_added = True
 
     batch_size, channels, cur_height, cur_width = images.shape
 
@@ -120,7 +123,7 @@ def resize_with_pad_torch(
     # Convert back to original format if needed
     if channels_last:
         padded_images = padded_images.permute(0, 2, 3, 1)  # [b, c, h, w] -> [b, h, w, c]
-        if batch_size == 1 and images.shape[0] == 1:
+        if batch_dim_added:
             padded_images = padded_images.squeeze(0)  # Remove batch dimension if it was added
 
     return padded_images