fix resampler projection

Author: anas-awadalla

open_flamingo/src/helpers.py

@@ -105,7 +105,7 @@ def __init__(
         """
         Perceiver module which takes in image features and outputs image tokens.
         Args:
-            dim (int): final dimension of the incoming image features
+            dim (int): dimension of the incoming image features
             dim_inner (int, optional): final dimension to project the incoming image features to;
                 also the final dimension of the outputted features. If None, no projection is used, and dim_inner = dim.
             depth (int, optional): number of layers. Defaults to 6.
@@ -124,17 +124,17 @@ def __init__(
         else:
             projection = None
             dim_inner = dim
-        super().__init__(dim_media=dim_inner, num_tokens_per_media=num_latents)
+        super().__init__(dim_media=dim, num_tokens_per_media=num_latents)
         self.projection = projection
-        self.latents = nn.Parameter(torch.randn(num_latents, dim_inner))
+        self.latents = nn.Parameter(torch.randn(num_latents, dim))
         # positional embeddings
         self.frame_embs = (
-            nn.Parameter(torch.randn(max_num_frames, dim_inner))
+            nn.Parameter(torch.randn(max_num_frames, dim))
             if exists(max_num_frames)
             else None
         )
         self.media_time_embs = (
-            nn.Parameter(torch.randn(max_num_media, 1, dim_inner))
+            nn.Parameter(torch.randn(max_num_media, 1, dim))
             if exists(max_num_media)
             else None
         )
@@ -145,14 +145,14 @@ def __init__(
                 nn.ModuleList(
                     [
                         PerceiverAttention(
-                            dim=dim_inner, dim_head=dim_head, heads=heads
+                            dim=dim, dim_head=dim_head, heads=heads
                         ),
-                        FeedForward(dim=dim_inner, mult=ff_mult),
+                        FeedForward(dim=dim, mult=ff_mult),
                     ]
                 )
             )
 
-        self.norm = nn.LayerNorm(dim_inner)
+        self.norm = nn.LayerNorm(dim)
 
     def forward(self, x):
         """
@@ -164,9 +164,6 @@ def forward(self, x):
         """
         b, T, F, v = x.shape[:4]
 
-        if exists(self.projection):
-            x = self.projection(x)
-
         # frame and media time embeddings
         if exists(self.frame_embs):
             frame_embs = repeat(self.frame_embs[:F], "F d -> b T F v d", b=b, T=T, v=v)
@@ -182,7 +179,11 @@ def forward(self, x):
         for attn, ff in self.layers:
             latents = attn(x, latents) + latents
             latents = ff(latents) + latents
-        return self.norm(latents)
+        
+        if exists(self.projection):
+            return self.projection(self.norm(latents)) 
+        else:
+            self.norm(latents)
 
 class LinearPatchProjection(VisionTokenizer):
     """Linear projection from patch features to image tokens."""