Add features_only support to inception_next

Author: rwightman

timm/models/inception_next.py

@@ -221,6 +221,7 @@ def __init__(
             self,
             in_chans=3,
             num_classes=1000,
+            output_stride=32,
             depths=(3, 3, 9, 3),
             dims=(96, 192, 384, 768),
             token_mixers=nn.Identity,
@@ -239,22 +240,30 @@ def __init__(
             token_mixers = [token_mixers] * num_stage
         if not isinstance(mlp_ratios, (list, tuple)):
             mlp_ratios = [mlp_ratios] * num_stage
-
         self.num_classes = num_classes
         self.drop_rate = drop_rate
+        self.feature_info = []
+
         self.stem = nn.Sequential(
             nn.Conv2d(in_chans, dims[0], kernel_size=4, stride=4),
             norm_layer(dims[0])
         )
 
-        self.stages = nn.Sequential()
         dp_rates = [x.tolist() for x in torch.linspace(0, drop_path_rate, sum(depths)).split(depths)]
-        stages = []
         prev_chs = dims[0]
+        curr_stride = 4
+        dilation = 1
         # feature resolution stages, each consisting of multiple residual blocks
+        self.stages = nn.Sequential()
         for i in range(num_stage):
+            stride = 2 if curr_stride == 2 or i > 0 else 1
+            if curr_stride >= output_stride and stride > 1:
+                dilation *= stride
+                stride = 1
+            curr_stride *= stride
+            first_dilation = 1 if dilation in (1, 2) else 2
             out_chs = dims[i]
-            stages.append(MetaNeXtStage(
+            self.stages.append(MetaNeXtStage(
                 prev_chs,
                 out_chs,
                 ds_stride=2 if i > 0 else 1,
@@ -267,7 +276,7 @@ def __init__(
                 mlp_ratio=mlp_ratios[i],
             ))
             prev_chs = out_chs
-        self.stages = nn.Sequential(*stages)
+            self.feature_info += [dict(num_chs=prev_chs, reduction=curr_stride, module=f'stages.{i}')]
         self.num_features = prev_chs
         self.head = head_fn(self.num_features, num_classes, drop=drop_rate)
         self.apply(self._init_weights)
@@ -353,7 +362,8 @@ def _create_inception_next(variant, pretrained=False, **kwargs):
     model = build_model_with_cfg(
         MetaNeXt, variant, pretrained,
         feature_cfg=dict(out_indices=(0, 1, 2, 3), flatten_sequential=True),
-        **kwargs)
+        **kwargs,
+    )
     return model