cleanup conv1x1 and conv3x3

src/diffusers/models/resnet.py

@@ -593,17 +593,18 @@ class ResnetBlockBigGANpp(nn.Module):
         self.fir = fir
         self.fir_kernel = fir_kernel
 
-        self.Conv_0 = conv3x3(in_ch, out_ch)
+        self.Conv_0 = conv2d(in_ch, out_ch, kernel_size=3, padding=1)
         if temb_dim is not None:
             self.Dense_0 = nn.Linear(temb_dim, out_ch)
-            self.Dense_0.weight.data = default_init()(self.Dense_0.weight.shape)
+            self.Dense_0.weight.data = variance_scaling()(self.Dense_0.weight.shape)
             nn.init.zeros_(self.Dense_0.bias)
 
         self.GroupNorm_1 = nn.GroupNorm(num_groups=min(out_ch // 4, 32), num_channels=out_ch, eps=1e-6)
         self.Dropout_0 = nn.Dropout(dropout)
-        self.Conv_1 = conv3x3(out_ch, out_ch, init_scale=init_scale)
+        self.Conv_1 = conv2d(out_ch, out_ch, init_scale=init_scale, kernel_size=3, padding=1)
         if in_ch != out_ch or up or down:
-            self.Conv_2 = conv1x1(in_ch, out_ch)
+            #1x1 convolution with DDPM initialization.
+            self.Conv_2 = conv2d(in_ch, out_ch, kernel_size=1, padding=0)
 
         self.skip_rescale = skip_rescale
         self.act = act
@@ -754,32 +755,19 @@ class RearrangeDim(nn.Module):
             raise ValueError(f"`len(tensor)`: {len(tensor)} has to be 2, 3 or 4.")
 
 
-def conv1x1(in_planes, out_planes, stride=1, bias=True, init_scale=1.0, padding=0):
+def conv2d(in_planes, out_planes, kernel_size=3, stride=1, bias=True, init_scale=1.0, padding=1):
-    """1x1 convolution with DDPM initialization."""
+    """nXn convolution with DDPM initialization."""
-    conv = nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=stride, padding=padding, bias=bias)
-    conv.weight.data = default_init(init_scale)(conv.weight.data.shape)
-    nn.init.zeros_(conv.bias)
-    return conv
-
-
-def conv3x3(in_planes, out_planes, stride=1, bias=True, dilation=1, init_scale=1.0, padding=1):
-    """3x3 convolution with DDPM initialization."""
     conv = nn.Conv2d(
-        in_planes, out_planes, kernel_size=3, stride=stride, padding=padding, dilation=dilation, bias=bias
+        in_planes, out_planes, kernel_size=kernel_size, stride=stride, padding=padding, bias=bias
     )
-    conv.weight.data = default_init(init_scale)(conv.weight.data.shape)
+    conv.weight.data = variance_scaling(init_scale)(conv.weight.data.shape)
     nn.init.zeros_(conv.bias)
     return conv
 
 
-def default_init(scale=1.0):
+def variance_scaling(scale=1.0, in_axis=1, out_axis=0, dtype=torch.float32, device="cpu"):
-    """The same initialization used in DDPM."""
-    scale = 1e-10 if scale == 0 else scale
-    return variance_scaling(scale, "fan_avg", "uniform")
-
-
-def variance_scaling(scale, mode, distribution, in_axis=1, out_axis=0, dtype=torch.float32, device="cpu"):
     """Ported from JAX."""
+    scale = 1e-10 if scale == 0 else scale
 
     def _compute_fans(shape, in_axis=1, out_axis=0):
         receptive_field_size = np.prod(shape) / shape[in_axis] / shape[out_axis]
@@ -789,21 +777,9 @@ def variance_scaling(scale, mode, distribution, in_axis=1, out_axis=0, dtype=tor
 
     def init(shape, dtype=dtype, device=device):
         fan_in, fan_out = _compute_fans(shape, in_axis, out_axis)
-        if mode == "fan_in":
-            denominator = fan_in
-        elif mode == "fan_out":
-            denominator = fan_out
-        elif mode == "fan_avg":
         denominator = (fan_in + fan_out) / 2
-        else:
-            raise ValueError("invalid mode for variance scaling initializer: {}".format(mode))
         variance = scale / denominator
-        if distribution == "normal":
-            return torch.randn(*shape, dtype=dtype, device=device) * np.sqrt(variance)
-        elif distribution == "uniform":
         return (torch.rand(*shape, dtype=dtype, device=device) * 2.0 - 1.0) * np.sqrt(3 * variance)
-        else:
-            raise ValueError("invalid distribution for variance scaling initializer")
 
     return init
 

src/diffusers/models/unet_sde_score_estimation.py

@@ -287,20 +287,12 @@ def downsample_2d(x, k=None, factor=2, gain=1):
     return upfirdn2d(x, torch.tensor(k, device=x.device), down=factor, pad=((p + 1) // 2, p // 2))
 
 
-def conv1x1(in_planes, out_planes, stride=1, bias=True, init_scale=1.0, padding=0):
+def conv2d(in_planes, out_planes, kernel_size=3, stride=1, bias=True, init_scale=1.0, padding=1):
-    """1x1 convolution with DDPM initialization."""
+    """nXn convolution with DDPM initialization."""
-    conv = nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=stride, padding=padding, bias=bias)
-    conv.weight.data = default_init(init_scale)(conv.weight.data.shape)
-    nn.init.zeros_(conv.bias)
-    return conv
-
-
-def conv3x3(in_planes, out_planes, stride=1, bias=True, dilation=1, init_scale=1.0, padding=1):
-    """3x3 convolution with DDPM initialization."""
     conv = nn.Conv2d(
-        in_planes, out_planes, kernel_size=3, stride=stride, padding=padding, dilation=dilation, bias=bias
+        in_planes, out_planes, kernel_size=kernel_size, stride=stride, padding=padding, bias=bias
     )
-    conv.weight.data = default_init(init_scale)(conv.weight.data.shape)
+    conv.weight.data = variance_scaling(init_scale)(conv.weight.data.shape)
     nn.init.zeros_(conv.bias)
     return conv
 
@@ -320,14 +312,9 @@ def get_act(nonlinearity):
         raise NotImplementedError("activation function does not exist!")
 
 
-def default_init(scale=1.0):
+def variance_scaling(scale=1.0, in_axis=1, out_axis=0, dtype=torch.float32, device="cpu"):
-    """The same initialization used in DDPM."""
-    scale = 1e-10 if scale == 0 else scale
-    return variance_scaling(scale, "fan_avg", "uniform")
-
-
-def variance_scaling(scale, mode, distribution, in_axis=1, out_axis=0, dtype=torch.float32, device="cpu"):
     """Ported from JAX."""
+    scale = 1e-10 if scale == 0 else scale
 
     def _compute_fans(shape, in_axis=1, out_axis=0):
         receptive_field_size = np.prod(shape) / shape[in_axis] / shape[out_axis]
@@ -337,21 +324,9 @@ def variance_scaling(scale, mode, distribution, in_axis=1, out_axis=0, dtype=tor
 
     def init(shape, dtype=dtype, device=device):
         fan_in, fan_out = _compute_fans(shape, in_axis, out_axis)
-        if mode == "fan_in":
-            denominator = fan_in
-        elif mode == "fan_out":
-            denominator = fan_out
-        elif mode == "fan_avg":
         denominator = (fan_in + fan_out) / 2
-        else:
-            raise ValueError("invalid mode for variance scaling initializer: {}".format(mode))
         variance = scale / denominator
-        if distribution == "normal":
-            return torch.randn(*shape, dtype=dtype, device=device) * np.sqrt(variance)
-        elif distribution == "uniform":
         return (torch.rand(*shape, dtype=dtype, device=device) * 2.0 - 1.0) * np.sqrt(3 * variance)
-        else:
-            raise ValueError("invalid distribution for variance scaling initializer")
 
     return init
 
@@ -361,7 +336,8 @@ class Combine(nn.Module):
 
     def __init__(self, dim1, dim2, method="cat"):
         super().__init__()
-        self.Conv_0 = conv1x1(dim1, dim2)
+        #1x1 convolution with DDPM initialization.
+        self.Conv_0 = conv2d(dim1, dim2, kernel_size=1, padding=0)
         self.method = method
 
     def forward(self, x, y):
@@ -386,7 +362,7 @@ class Upsample(nn.Module):
                 up=True,
                 resample_kernel=fir_kernel,
                 use_bias=True,
-                kernel_init=default_init(),
+                kernel_init=variance_scaling(),
             )
         self.fir = fir
         self.with_conv = with_conv
@@ -415,7 +391,7 @@ class Downsample(nn.Module):
                 down=True,
                 resample_kernel=fir_kernel,
                 use_bias=True,
-                kernel_init=default_init(),
+                kernel_init=variance_scaling(),
             )
         self.fir = fir
         self.fir_kernel = fir_kernel
@@ -528,10 +504,10 @@ class NCSNpp(ModelMixin, ConfigMixin):
 
         if conditional:
             modules.append(nn.Linear(embed_dim, nf * 4))
-            modules[-1].weight.data = default_init()(modules[-1].weight.shape)
+            modules[-1].weight.data = variance_scaling()(modules[-1].weight.shape)
             nn.init.zeros_(modules[-1].bias)
             modules.append(nn.Linear(nf * 4, nf * 4))
-            modules[-1].weight.data = default_init()(modules[-1].weight.shape)
+            modules[-1].weight.data = variance_scaling()(modules[-1].weight.shape)
             nn.init.zeros_(modules[-1].bias)
 
         AttnBlock = functools.partial(AttentionBlock, overwrite_linear=True, rescale_output_factor=math.sqrt(2.0))
@@ -566,7 +542,7 @@ class NCSNpp(ModelMixin, ConfigMixin):
         if progressive_input != "none":
             input_pyramid_ch = channels
 
-        modules.append(conv3x3(channels, nf))
+        modules.append(conv2d(channels, nf, kernel_size=3, padding=1))
         hs_c = [nf]
 
         in_ch = nf
@@ -615,18 +591,18 @@ class NCSNpp(ModelMixin, ConfigMixin):
                 if i_level == self.num_resolutions - 1:
                     if progressive == "output_skip":
                         modules.append(nn.GroupNorm(num_groups=min(in_ch // 4, 32), num_channels=in_ch, eps=1e-6))
-                        modules.append(conv3x3(in_ch, channels, init_scale=init_scale))
+                        modules.append(conv2d(in_ch, channels, init_scale=init_scale, kernel_size=3, padding=1))
                         pyramid_ch = channels
                     elif progressive == "residual":
                         modules.append(nn.GroupNorm(num_groups=min(in_ch // 4, 32), num_channels=in_ch, eps=1e-6))
-                        modules.append(conv3x3(in_ch, in_ch, bias=True))
+                        modules.append(conv2d(in_ch, in_ch, bias=True, kernel_size=3, padding=1))
                         pyramid_ch = in_ch
                     else:
                         raise ValueError(f"{progressive} is not a valid name.")
                 else:
                     if progressive == "output_skip":
                         modules.append(nn.GroupNorm(num_groups=min(in_ch // 4, 32), num_channels=in_ch, eps=1e-6))
-                        modules.append(conv3x3(in_ch, channels, bias=True, init_scale=init_scale))
+                        modules.append(conv2d(in_ch, channels, bias=True, init_scale=init_scale, kernel_size=3, padding=1))
                         pyramid_ch = channels
                     elif progressive == "residual":
                         modules.append(pyramid_upsample(in_ch=pyramid_ch, out_ch=in_ch))
@@ -641,7 +617,7 @@ class NCSNpp(ModelMixin, ConfigMixin):
 
         if progressive != "output_skip":
             modules.append(nn.GroupNorm(num_groups=min(in_ch // 4, 32), num_channels=in_ch, eps=1e-6))
-            modules.append(conv3x3(in_ch, channels, init_scale=init_scale))
+            modules.append(conv2d(in_ch, channels, init_scale=init_scale))
 
         self.all_modules = nn.ModuleList(modules)