Add norm param to ResNet (#7752)

Fixes #7294  .

### Description
Adds a `norm` param to ResNet

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [x] New tests added to cover the changes.
- [x] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [x] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [x] In-line docstrings updated.
- [x] Documentation updated, tested `make html` command in the `docs/`
folder.

---------

Signed-off-by: Peter Kaplinsky <peterkaplinsky@gmail.com>
Co-authored-by: Peter Kaplinsky <peterkaplinsky@gmail.com>
Co-authored-by: YunLiu <55491388+KumoLiu@users.noreply.github.com>

monai/networks/nets/daf3d.py

@@ -13,6 +13,7 @@
 
 from collections import OrderedDict
 from collections.abc import Callable, Sequence
+from functools import partial
 
 import torch
 import torch.nn as nn
@@ -25,6 +26,7 @@
 from monai.networks.blocks.convolutions import Convolution
 from monai.networks.blocks.feature_pyramid_network import ExtraFPNBlock, FeaturePyramidNetwork
 from monai.networks.layers.factories import Conv, Norm
+from monai.networks.layers.utils import get_norm_layer
 from monai.networks.nets.resnet import ResNet, ResNetBottleneck
 
 __all__ = [
@@ -170,27 +172,31 @@ class Daf3dResNetBottleneck(ResNetBottleneck):
         spatial_dims: number of spatial dimensions of the input image.
         stride: stride to use for second conv layer.
         downsample: which downsample layer to use.
+        norm: which normalization layer to use. Defaults to group.
     """
 
     expansion = 2
 
-    def __init__(self, in_planes, planes, spatial_dims=3, stride=1, downsample=None):
-        norm_type: Callable = Norm[Norm.GROUP, spatial_dims]
+    def __init__(
+        self, in_planes, planes, spatial_dims=3, stride=1, downsample=None, norm=("group", {"num_groups": 32})
+    ):
         conv_type: Callable = Conv[Conv.CONV, spatial_dims]
 
+        norm_layer = partial(get_norm_layer, name=norm, spatial_dims=spatial_dims)
+
         # in case downsample uses batch norm, change to group norm
         if isinstance(downsample, nn.Sequential):
             downsample = nn.Sequential(
                 conv_type(in_planes, planes * self.expansion, kernel_size=1, stride=stride, bias=False),
-                norm_type(num_groups=32, num_channels=planes * self.expansion),
+                norm_layer(channels=planes * self.expansion),
             )
 
         super().__init__(in_planes, planes, spatial_dims, stride, downsample)
 
         # change norm from batch to group norm
-        self.bn1 = norm_type(num_groups=32, num_channels=planes)
-        self.bn2 = norm_type(num_groups=32, num_channels=planes)
-        self.bn3 = norm_type(num_groups=32, num_channels=planes * self.expansion)
+        self.bn1 = norm_layer(channels=planes)
+        self.bn2 = norm_layer(channels=planes)
+        self.bn3 = norm_layer(channels=planes * self.expansion)
 
         # adapt second convolution to work with groups
         self.conv2 = conv_type(planes, planes, kernel_size=3, padding=1, stride=stride, groups=32, bias=False)
@@ -212,8 +218,10 @@ class Daf3dResNetDilatedBottleneck(Daf3dResNetBottleneck):
         downsample: which downsample layer to use.
     """
 
-    def __init__(self, in_planes, planes, spatial_dims=3, stride=1, downsample=None):
-        super().__init__(in_planes, planes, spatial_dims, stride, downsample)
+    def __init__(
+        self, in_planes, planes, spatial_dims=3, stride=1, downsample=None, norm=("group", {"num_groups": 32})
+    ):
+        super().__init__(in_planes, planes, spatial_dims, stride, downsample, norm)
 
         # add dilation in second convolution
         conv_type: Callable = Conv[Conv.CONV, spatial_dims]

monai/networks/nets/resnet.py

@@ -22,8 +22,8 @@
 import torch.nn as nn
 
 from monai.networks.blocks.encoder import BaseEncoder
-from monai.networks.layers.factories import Conv, Norm, Pool
-from monai.networks.layers.utils import get_act_layer, get_pool_layer
+from monai.networks.layers.factories import Conv, Pool
+from monai.networks.layers.utils import get_act_layer, get_norm_layer, get_pool_layer
 from monai.utils import ensure_tuple_rep
 from monai.utils.module import look_up_option, optional_import
 
@@ -79,6 +79,7 @@ def __init__(
         stride: int = 1,
         downsample: nn.Module | partial | None = None,
         act: str | tuple = ("relu", {"inplace": True}),
+        norm: str | tuple = "batch",
     ) -> None:
         """
         Args:
@@ -88,17 +89,18 @@ def __init__(
             stride: stride to use for first conv layer.
             downsample: which downsample layer to use.
             act: activation type and arguments. Defaults to relu.
+            norm: feature normalization type and arguments. Defaults to batch norm.
         """
         super().__init__()
 
         conv_type: Callable = Conv[Conv.CONV, spatial_dims]
-        norm_type: Callable = Norm[Norm.BATCH, spatial_dims]
+        norm_layer = get_norm_layer(name=norm, spatial_dims=spatial_dims, channels=planes)
 
         self.conv1 = conv_type(in_planes, planes, kernel_size=3, padding=1, stride=stride, bias=False)
-        self.bn1 = norm_type(planes)
+        self.bn1 = norm_layer
         self.act = get_act_layer(name=act)
         self.conv2 = conv_type(planes, planes, kernel_size=3, padding=1, bias=False)
-        self.bn2 = norm_type(planes)
+        self.bn2 = norm_layer
         self.downsample = downsample
         self.stride = stride
 
@@ -132,6 +134,7 @@ def __init__(
         stride: int = 1,
         downsample: nn.Module | partial | None = None,
         act: str | tuple = ("relu", {"inplace": True}),
+        norm: str | tuple = "batch",
     ) -> None:
         """
         Args:
@@ -141,19 +144,20 @@ def __init__(
             stride: stride to use for second conv layer.
             downsample: which downsample layer to use.
             act: activation type and arguments. Defaults to relu.
+            norm: feature normalization type and arguments. Defaults to batch norm.
         """
 
         super().__init__()
 
         conv_type: Callable = Conv[Conv.CONV, spatial_dims]
-        norm_type: Callable = Norm[Norm.BATCH, spatial_dims]
+        norm_layer = partial(get_norm_layer, name=norm, spatial_dims=spatial_dims)
 
         self.conv1 = conv_type(in_planes, planes, kernel_size=1, bias=False)
-        self.bn1 = norm_type(planes)
+        self.bn1 = norm_layer(channels=planes)
         self.conv2 = conv_type(planes, planes, kernel_size=3, stride=stride, padding=1, bias=False)
-        self.bn2 = norm_type(planes)
+        self.bn2 = norm_layer(channels=planes)
         self.conv3 = conv_type(planes, planes * self.expansion, kernel_size=1, bias=False)
-        self.bn3 = norm_type(planes * self.expansion)
+        self.bn3 = norm_layer(channels=planes * self.expansion)
         self.act = get_act_layer(name=act)
         self.downsample = downsample
         self.stride = stride
@@ -207,6 +211,7 @@ class ResNet(nn.Module):
         feed_forward: whether to add the FC layer for the output, default to `True`.
         bias_downsample: whether to use bias term in the downsampling block when `shortcut_type` is 'B', default to `True`.
         act: activation type and arguments. Defaults to relu.
+        norm: feature normalization type and arguments. Defaults to batch norm.
 
     """
 
@@ -226,6 +231,7 @@ def __init__(
         feed_forward: bool = True,
         bias_downsample: bool = True,  # for backwards compatibility (also see PR #5477)
         act: str | tuple = ("relu", {"inplace": True}),
+        norm: str | tuple = "batch",
     ) -> None:
         super().__init__()
 
@@ -238,7 +244,6 @@ def __init__(
                 raise ValueError("Unknown block '%s', use basic or bottleneck" % block)
 
         conv_type: type[nn.Conv1d | nn.Conv2d | nn.Conv3d] = Conv[Conv.CONV, spatial_dims]
-        norm_type: type[nn.BatchNorm1d | nn.BatchNorm2d | nn.BatchNorm3d] = Norm[Norm.BATCH, spatial_dims]
         pool_type: type[nn.MaxPool1d | nn.MaxPool2d | nn.MaxPool3d] = Pool[Pool.MAX, spatial_dims]
         avgp_type: type[nn.AdaptiveAvgPool1d | nn.AdaptiveAvgPool2d | nn.AdaptiveAvgPool3d] = Pool[
             Pool.ADAPTIVEAVG, spatial_dims
@@ -262,7 +267,9 @@ def __init__(
             padding=tuple(k // 2 for k in conv1_kernel_size),
             bias=False,
         )
-        self.bn1 = norm_type(self.in_planes)
+
+        norm_layer = get_norm_layer(name=norm, spatial_dims=spatial_dims, channels=self.in_planes)
+        self.bn1 = norm_layer
         self.act = get_act_layer(name=act)
         self.maxpool = pool_type(kernel_size=3, stride=2, padding=1)
         self.layer1 = self._make_layer(block, block_inplanes[0], layers[0], spatial_dims, shortcut_type)
@@ -275,7 +282,7 @@ def __init__(
         for m in self.modules():
             if isinstance(m, conv_type):
                 nn.init.kaiming_normal_(torch.as_tensor(m.weight), mode="fan_out", nonlinearity="relu")
-            elif isinstance(m, norm_type):
+            elif isinstance(m, type(norm_layer)):
                 nn.init.constant_(torch.as_tensor(m.weight), 1)
                 nn.init.constant_(torch.as_tensor(m.bias), 0)
             elif isinstance(m, nn.Linear):
@@ -295,9 +302,9 @@ def _make_layer(
         spatial_dims: int,
         shortcut_type: str,
         stride: int = 1,
+        norm: str | tuple = "batch",
     ) -> nn.Sequential:
         conv_type: Callable = Conv[Conv.CONV, spatial_dims]
-        norm_type: Callable = Norm[Norm.BATCH, spatial_dims]
 
         downsample: nn.Module | partial | None = None
         if stride != 1 or self.in_planes != planes * block.expansion:
@@ -317,18 +324,23 @@ def _make_layer(
                         stride=stride,
                         bias=self.bias_downsample,
                     ),
-                    norm_type(planes * block.expansion),
+                    get_norm_layer(name=norm, spatial_dims=spatial_dims, channels=planes * block.expansion),
                 )
 
         layers = [
             block(
-                in_planes=self.in_planes, planes=planes, spatial_dims=spatial_dims, stride=stride, downsample=downsample
+                in_planes=self.in_planes,
+                planes=planes,
+                spatial_dims=spatial_dims,
+                stride=stride,
+                downsample=downsample,
+                norm=norm,
             )
         ]
 
         self.in_planes = planes * block.expansion
         for _i in range(1, blocks):
-            layers.append(block(self.in_planes, planes, spatial_dims=spatial_dims))
+            layers.append(block(self.in_planes, planes, spatial_dims=spatial_dims, norm=norm))
 
         return nn.Sequential(*layers)
 

tests/test_resnet.py

@@ -202,13 +202,30 @@
     (1, 3),
 ]
 
+TEST_CASE_9 = [  # Layer norm
+    {
+        "block": ResNetBlock,
+        "layers": [3, 4, 6, 3],
+        "block_inplanes": [64, 128, 256, 512],
+        "spatial_dims": 1,
+        "n_input_channels": 2,
+        "num_classes": 3,
+        "conv1_t_size": [3],
+        "conv1_t_stride": 1,
+        "act": ("relu", {"inplace": False}),
+        "norm": ("layer", {"normalized_shape": (64, 32)}),
+    },
+    (1, 2, 32),
+    (1, 3),
+]
+
 TEST_CASES = []
 PRETRAINED_TEST_CASES = []
 for case in [TEST_CASE_1, TEST_CASE_2, TEST_CASE_3, TEST_CASE_2_A, TEST_CASE_3_A]:
     for model in [resnet10, resnet18, resnet34, resnet50, resnet101, resnet152, resnet200]:
         TEST_CASES.append([model, *case])
         PRETRAINED_TEST_CASES.append([model, *case])
-for case in [TEST_CASE_5, TEST_CASE_5_A, TEST_CASE_6, TEST_CASE_7, TEST_CASE_8]:
+for case in [TEST_CASE_5, TEST_CASE_5_A, TEST_CASE_6, TEST_CASE_7, TEST_CASE_8, TEST_CASE_9]:
     TEST_CASES.append([ResNet, *case])
 
 TEST_SCRIPT_CASES = [