AIGC笔记--Stable Diffusion源码剖析之UNetModel

梦应逍遥 · 2024-8-6 00:35:10

1--媒介

         以论文《High-Resolution Image Synthesis with Latent Diffusion Models》开源的项目为例，剖析Stable Diffusion经典组成部分，巩固学习加深印象。
  2--UNetModel

一个可以debug的小demo：SD_UNet
         以文生图为例，剖析UNetModel核心组成模块。
  2-1--Forward统辖

提供的文生图Demo中，实际传入的参数只有x、timesteps和context三个，此中：
          x 表现随机初始化的噪声Tensor（shape: [B*2, 4, 64, 64]，*2表现利用Classifier-Free Diffusion Guidance）。
          timesteps 表现去噪过程中每一轮传入的timestep（shape: [B*2]）。
    context表现颠末CLIP编码后对应的文本Prompt（shape: [B*2, 77, 768]）。

def forward(self, x, timesteps=None, context=None, y=None,**kwargs):
"""
Apply the model to an input batch.
:param x: an [N x C x ...] Tensor of inputs.
:param timesteps: a 1-D batch of timesteps.
:param context: conditioning plugged in via crossattn
:param y: an [N] Tensor of labels, if class-conditional.
:return: an [N x C x ...] Tensor of outputs.
"""
assert (y is not None) == (
self.num_classes is not None
), "must specify y if and only if the model is class-conditional"
hs = []
t_emb = timestep_embedding(timesteps, self.model_channels, repeat_only=False) # Create sinusoidal timestep embeddings.
emb = self.time_embed(t_emb) # MLP
if self.num_classes is not None:
assert y.shape == (x.shape[0],)
emb = emb + self.label_emb(y)
h = x.type(self.dtype)
for module in self.input_blocks:
h = module(h, emb, context)
hs.append(h)
h = self.middle_block(h, emb, context)
for module in self.output_blocks:
h = th.cat([h, hs.pop()], dim=1)
h = module(h, emb, context)
h = h.type(x.dtype)
if self.predict_codebook_ids:
return self.id_predictor(h)
else:
return self.out(h)

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2-2--timestep embedding生成

利用函数 timestep_embedding() 和 self.time_embed() 对传入的timestep进行位置编码，生成sinusoidal timestep embeddings。
此中 timestep_embedding() 函数定义如下，而self.time_embed()是一个MLP函数。

def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
"""
Create sinusoidal timestep embeddings.
:param timesteps: a 1-D Tensor of N indices, one per batch element.
These may be fractional.
:param dim: the dimension of the output.
:param max_period: controls the minimum frequency of the embeddings.
:return: an [N x dim] Tensor of positional embeddings.
"""
if not repeat_only:
half = dim // 2
freqs = torch.exp(
-math.log(max_period) * torch.arange(start=0, end=half, dtype=torch.float32) / half
).to(device=timesteps.device)
args = timesteps[:, None].float() * freqs[None]
embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
if dim % 2:
embedding = torch.cat([embedding, torch.zeros_like(embedding[:, :1])], dim=-1)
else:
embedding = repeat(timesteps, 'b -> b d', d=dim)
return embedding

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self.time_embed = nn.Sequential(
linear(model_channels, time_embed_dim),
nn.SiLU(),
linear(time_embed_dim, time_embed_dim),
)

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2-3--self.input_blocks下采样

在 Forward() 中，利用 self.input_blocks 将输入噪声进行分辨率下采样，颠末下采样详细维度变化为：[B*2, 4, 64, 64] > [B*2, 1280, 8, 8]；
下采样模块共有12个 module，其组成如下：

ModuleList(
(0): TimestepEmbedSequential(
(0): Conv2d(4, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(1-2): 2 x TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=320, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 320, eps=1e-06, affine=True)
(proj_in): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=320, out_features=320, bias=False)
(to_v): Linear(in_features=320, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=320, out_features=2560, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=1280, out_features=320, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=768, out_features=320, bias=False)
(to_v): Linear(in_features=768, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
)
)
(3): TimestepEmbedSequential(
(0): Downsample(
(op): Conv2d(320, 320, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1))
)
)
(4): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(320, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=640, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(320, 640, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 640, eps=1e-06, affine=True)
(proj_in): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=640, out_features=640, bias=False)
(to_v): Linear(in_features=640, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=640, out_features=5120, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=2560, out_features=640, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=768, out_features=640, bias=False)
(to_v): Linear(in_features=768, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
)
)
(5): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=640, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 640, eps=1e-06, affine=True)
(proj_in): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=640, out_features=640, bias=False)
(to_v): Linear(in_features=640, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=640, out_features=5120, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=2560, out_features=640, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=768, out_features=640, bias=False)
(to_v): Linear(in_features=768, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
)
)
(6): TimestepEmbedSequential(
(0): Downsample(
(op): Conv2d(640, 640, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1))
)
)
(7): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(640, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(640, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 1280, eps=1e-06, affine=True)
(proj_in): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=1280, out_features=1280, bias=False)
(to_v): Linear(in_features=1280, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=1280, out_features=10240, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=5120, out_features=1280, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=768, out_features=1280, bias=False)
(to_v): Linear(in_features=768, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
)
)
(8): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 1280, eps=1e-06, affine=True)
(proj_in): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=1280, out_features=1280, bias=False)
(to_v): Linear(in_features=1280, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=1280, out_features=10240, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=5120, out_features=1280, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=768, out_features=1280, bias=False)
(to_v): Linear(in_features=768, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
)
)
(9): TimestepEmbedSequential(
(0): Downsample(
(op): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1))
)
)
(10-11): 2 x TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
)
)

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12个 module 都利用了 TimestepEmbedSequential 类进行封装，根据不同的网络层，将输入噪声x与timestep embedding和prompt context进行运算。

class TimestepEmbedSequential(nn.Sequential, TimestepBlock):
"""
A sequential module that passes timestep embeddings to the children that
support it as an extra input.
"""
def forward(self, x, emb, context=None):
for layer in self:
if isinstance(layer, TimestepBlock):
x = layer(x, emb)
elif isinstance(layer, SpatialTransformer):
x = layer(x, context)
else:
x = layer(x)
return x

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2-3-1--Module0

Module 0 是一个2D卷积层，重要对输入噪声进行特性提取；

# init 初始化
self.input_blocks = nn.ModuleList(
[
TimestepEmbedSequential(
conv_nd(dims, in_channels, model_channels, 3, padding=1)
)
]
)
# 打印 self.input_blocks[0]
TimestepEmbedSequential(
(0): Conv2d(4, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)

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2-3-2--Module1和Module2

Module1和Module2的结构相同，都由一个ResBlock和一个SpatialTransformer组成；

# init 初始化
for _ in range(num_res_blocks):
layers = [
ResBlock(
ch,
time_embed_dim,
dropout,
out_channels=mult * model_channels,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
)
]
ch = mult * model_channels
if ds in attention_resolutions:
if num_head_channels == -1:
dim_head = ch // num_heads
else:
num_heads = ch // num_head_channels
dim_head = num_head_channels
if legacy:
#num_heads = 1
dim_head = ch // num_heads if use_spatial_transformer else num_head_channels
layers.append(
AttentionBlock(
ch,
use_checkpoint=use_checkpoint,
num_heads=num_heads,
num_head_channels=dim_head,
use_new_attention_order=use_new_attention_order,
) if not use_spatial_transformer else SpatialTransformer(
ch, num_heads, dim_head, depth=transformer_depth, context_dim=context_dim
)
)
self.input_blocks.append(TimestepEmbedSequential(*layers))
self._feature_size += ch
input_block_chans.append(ch)
# 打印 self.input_blocks[1]
TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=320, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 320, eps=1e-06, affine=True)
(proj_in): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=320, out_features=320, bias=False)
(to_v): Linear(in_features=320, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=320, out_features=2560, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=1280, out_features=320, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=768, out_features=320, bias=False)
(to_v): Linear(in_features=768, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
)
)
# 打印 self.input_blocks[2]
TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=320, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 320, eps=1e-06, affine=True)
(proj_in): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=320, out_features=320, bias=False)
(to_v): Linear(in_features=320, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=320, out_features=2560, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=1280, out_features=320, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=768, out_features=320, bias=False)
(to_v): Linear(in_features=768, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
)
)

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2-3-3--Module3

Module3是一个下采样2D卷积层。

# init 初始化
if level != len(channel_mult) - 1:
out_ch = ch
self.input_blocks.append(
TimestepEmbedSequential(
ResBlock(
ch,
time_embed_dim,
dropout,
out_channels=out_ch,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
down=True,
)
if resblock_updown
else Downsample(
ch, conv_resample, dims=dims, out_channels=out_ch
)
)
)
# 打印 self.input_blocks[3]
TimestepEmbedSequential(
(0): Downsample(
(op): Conv2d(320, 320, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1))
)
)

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2-3-4--Module4、Module5、Module7和Module8

   与Module1和Module2的结构相同，都由一个ResBlock和一个SpatialTransformer组成，只有特性维度上的区别；
  2-3-4--Module6和Module9

   与Module3的结构相同，是一个下采样2D卷积层。
  2-3--5-Module10和Module11

   Module10和Module12的结构相同，只由一个ResBlock组成。

# 打印 self.input_blocks[10]
TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
)
# 打印 self.input_blocks[11]
TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
)

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2-3-6--ResBlock

ResBlock的输入是噪声图x和timestep embedding，通过卷积处理和残差毗连等方式将timestep embedding融入噪声图特性中，核心代码如下：

class ResBlock(TimestepBlock):
"""
A residual block that can optionally change the number of channels.
:param channels: the number of input channels.
:param emb_channels: the number of timestep embedding channels.
:param dropout: the rate of dropout.
:param out_channels: if specified, the number of out channels.
:param use_conv: if True and out_channels is specified, use a spatial
convolution instead of a smaller 1x1 convolution to change the
channels in the skip connection.
:param dims: determines if the signal is 1D, 2D, or 3D.
:param use_checkpoint: if True, use gradient checkpointing on this module.
:param up: if True, use this block for upsampling.
:param down: if True, use this block for downsampling.
"""
def __init__(
self,
channels,
emb_channels,
dropout,
out_channels=None,
use_conv=False,
use_scale_shift_norm=False,
dims=2,
use_checkpoint=False,
up=False,
down=False,
):
super().__init__()
self.channels = channels
self.emb_channels = emb_channels
self.dropout = dropout
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.use_checkpoint = use_checkpoint
self.use_scale_shift_norm = use_scale_shift_norm
self.in_layers = nn.Sequential(
normalization(channels),
nn.SiLU(),
conv_nd(dims, channels, self.out_channels, 3, padding=1),
)
self.updown = up or down
if up:
self.h_upd = Upsample(channels, False, dims)
self.x_upd = Upsample(channels, False, dims)
elif down:
self.h_upd = Downsample(channels, False, dims)
self.x_upd = Downsample(channels, False, dims)
else:
self.h_upd = self.x_upd = nn.Identity()
self.emb_layers = nn.Sequential(
nn.SiLU(),
linear(
emb_channels,
2 * self.out_channels if use_scale_shift_norm else self.out_channels,
),
)
self.out_layers = nn.Sequential(
normalization(self.out_channels),
nn.SiLU(),
nn.Dropout(p=dropout),
zero_module(
conv_nd(dims, self.out_channels, self.out_channels, 3, padding=1)
),
)
if self.out_channels == channels:
self.skip_connection = nn.Identity()
elif use_conv:
self.skip_connection = conv_nd(
dims, channels, self.out_channels, 3, padding=1
)
else:
self.skip_connection = conv_nd(dims, channels, self.out_channels, 1)
def forward(self, x, emb):
"""
Apply the block to a Tensor, conditioned on a timestep embedding.
:param x: an [N x C x ...] Tensor of features.
:param emb: an [N x emb_channels] Tensor of timestep embeddings.
:return: an [N x C x ...] Tensor of outputs.
"""
return checkpoint(
self._forward, (x, emb), self.parameters(), self.use_checkpoint
)
def _forward(self, x, emb):
if self.updown:
in_rest, in_conv = self.in_layers[:-1], self.in_layers[-1]
h = in_rest(x)
h = self.h_upd(h)
x = self.x_upd(x)
h = in_conv(h)
else:
h = self.in_layers(x) # [6, 320, 64, 64] -> [6, 320, 64, 64]
emb_out = self.emb_layers(emb).type(h.dtype) # [6, 1280] -> [6, 320]
while len(emb_out.shape) < len(h.shape): # [6, 320] -> [6, 320, 1, 1]
emb_out = emb_out[..., None]
if self.use_scale_shift_norm:
out_norm, out_rest = self.out_layers[0], self.out_layers[1:]
scale, shift = th.chunk(emb_out, 2, dim=1)
h = out_norm(h) * (1 + scale) + shift
h = out_rest(h)
else:
h = h + emb_out # [6, 320, 64, 64] + [6, 320, 1, 1] -> [6, 320, 64, 64]
h = self.out_layers(h) # [6, 320, 64, 64]
return self.skip_connection(x) + h

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2-3-7--SpatialTransformer

SpatialTransformer的输入是噪声图x和文本特性context，通过CrossAttention机制将文本特性融入到噪声图x中，完成条件驱动文生图，核心代码如下：

from inspect import isfunction
import math
import torch
import torch.nn.functional as F
from torch import nn, einsum
from einops import rearrange, repeat
from util import checkpoint
def exists(val):
return val is not None
def uniq(arr):
return{el: True for el in arr}.keys()
def default(val, d):
if exists(val):
return val
return d() if isfunction(d) else d
def max_neg_value(t):
return -torch.finfo(t.dtype).max
def init_(tensor):
dim = tensor.shape[-1]
std = 1 / math.sqrt(dim)
tensor.uniform_(-std, std)
return tensor
# feedforward
class GEGLU(nn.Module):
def __init__(self, dim_in, dim_out):
super().__init__()
self.proj = nn.Linear(dim_in, dim_out * 2)
def forward(self, x):
x, gate = self.proj(x).chunk(2, dim=-1)
return x * F.gelu(gate)
class FeedForward(nn.Module):
def __init__(self, dim, dim_out=None, mult=4, glu=False, dropout=0.):
super().__init__()
inner_dim = int(dim * mult)
dim_out = default(dim_out, dim)
project_in = nn.Sequential(
nn.Linear(dim, inner_dim),
nn.GELU()
) if not glu else GEGLU(dim, inner_dim)
self.net = nn.Sequential(
project_in,
nn.Dropout(dropout),
nn.Linear(inner_dim, dim_out)
)
def forward(self, x):
return self.net(x)
def zero_module(module):
"""
Zero out the parameters of a module and return it.
"""
for p in module.parameters():
p.detach().zero_()
return module
def Normalize(in_channels):
return torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
class CrossAttention(nn.Module):
def __init__(self, query_dim, context_dim=None, heads=8, dim_head=64, dropout=0.):
super().__init__()
inner_dim = dim_head * heads # dim_head: 40, heads: 8
context_dim = default(context_dim, query_dim)
self.scale = dim_head ** -0.5
self.heads = heads
self.to_q = nn.Linear(query_dim, inner_dim, bias=False)
self.to_k = nn.Linear(context_dim, inner_dim, bias=False)
self.to_v = nn.Linear(context_dim, inner_dim, bias=False)
self.to_out = nn.Sequential(
nn.Linear(inner_dim, query_dim),
nn.Dropout(dropout)
)
def forward(self, x, context=None, mask=None):
h = self.heads # 8
q = self.to_q(x) # [6, 4096, 320] -> [6, 4096, 320]
context = default(context, x) # return context [6, 77, 768]
k = self.to_k(context) # [6, 77, 768] -> [6, 77, 320]
v = self.to_v(context) # [6, 77, 768] -> [6, 77, 320]
q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> (b h) n d', h=h), (q, k, v)) # [6, 4096, 320] -> [48, 4096, 40] # [6, 77, 320] -> [48, 77, 40]
sim = einsum('b i d, b j d -> b i j', q, k) * self.scale # [48, 4096, 40] * [48, 77, 40] -> [48, 4096, 77]
if exists(mask):
mask = rearrange(mask, 'b ... -> b (...)')
max_neg_value = -torch.finfo(sim.dtype).max
mask = repeat(mask, 'b j -> (b h) () j', h=h)
sim.masked_fill_(~mask, max_neg_value)
# attention, what we cannot get enough of
attn = sim.softmax(dim=-1) # softmax
out = einsum('b i j, b j d -> b i d', attn, v) # [48, 4096, 77] * [48, 77, 40] -> [48, 4096, 40]
out = rearrange(out, '(b h) n d -> b n (h d)', h=h) # [48, 4096, 40] -> [6, 4096, 320]
return self.to_out(out)
class BasicTransformerBlock(nn.Module):
def __init__(self, dim, n_heads, d_head, dropout=0., context_dim=None, gated_ff=True, checkpoint=True):
super().__init__()
self.attn1 = CrossAttention(query_dim=dim, heads=n_heads, dim_head=d_head, dropout=dropout) # is a self-attention
self.ff = FeedForward(dim, dropout=dropout, glu=gated_ff)
self.attn2 = CrossAttention(query_dim=dim, context_dim=context_dim,
heads=n_heads, dim_head=d_head, dropout=dropout) # is self-attn if context is none
self.norm1 = nn.LayerNorm(dim)
self.norm2 = nn.LayerNorm(dim)
self.norm3 = nn.LayerNorm(dim)
self.checkpoint = checkpoint
def forward(self, x, context=None):
return checkpoint(self._forward, (x, context), self.parameters(), self.checkpoint)
def _forward(self, x, context=None):
x = self.attn1(self.norm1(x)) + x # self Attention, [6, 4096, 320] -> [6, 4096, 320]
x = self.attn2(self.norm2(x), context=context) + x # cross Attention, [6, 4096, 320] -> [6, 4096, 320]
x = self.ff(self.norm3(x)) + x # FFN, [6, 4096, 320] -> [6, 4096, 320]
return x
class SpatialTransformer(nn.Module):
"""
Transformer block for image-like data.
First, project the input (aka embedding)
and reshape to b, t, d.
Then apply standard transformer action.
Finally, reshape to image
"""
def __init__(self, in_channels, n_heads, d_head,
depth=1, dropout=0., context_dim=None):
super().__init__()
self.in_channels = in_channels
inner_dim = n_heads * d_head
self.norm = Normalize(in_channels)
self.proj_in = nn.Conv2d(in_channels,
inner_dim,
kernel_size=1,
stride=1,
padding=0)
self.transformer_blocks = nn.ModuleList(
[BasicTransformerBlock(inner_dim, n_heads, d_head, dropout=dropout, context_dim=context_dim)
for d in range(depth)]
)
self.proj_out = zero_module(nn.Conv2d(inner_dim,
in_channels,
kernel_size=1,
stride=1,
padding=0))
def forward(self, x, context=None):
# note: if no context is given, cross-attention defaults to self-attention
b, c, h, w = x.shape # [6, 320, 64, 64]
x_in = x
x = self.norm(x) # [6, 320, 64, 64]
x = self.proj_in(x) # [6, 320, 64, 64]
x = rearrange(x, 'b c h w -> b (h w) c') # [6, 4096, 320]
for block in self.transformer_blocks:
x = block(x, context=context)
x = rearrange(x, 'b (h w) c -> b c h w', h=h, w=w)
x = self.proj_out(x)
return x + x_in

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2-4--self.middle_block

self.middle_block由两个ResBlock和一个SpatialTransformer组成：

TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 1280, eps=1e-06, affine=True)
(proj_in): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=1280, out_features=1280, bias=False)
(to_v): Linear(in_features=1280, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=1280, out_features=10240, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=5120, out_features=1280, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=768, out_features=1280, bias=False)
(to_v): Linear(in_features=768, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(2): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Identity()
)
)

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2-5--self.output_blocks上采样

在 Forward() 中，利用 self.output_blocks 将噪声图进行分辨率上采样，颠末上采样详细维度变化为：[B*2, 1280, 8, 8] > [B*2, 4, 64, 64]；
下采样模块共有12个 module，其结构与下采样模块类似，组成如下：

ModuleList(
(0-1): 2 x TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 2560, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(2560, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(2560, 1280, kernel_size=(1, 1), stride=(1, 1))
)
)
(2): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 2560, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(2560, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(2560, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(1): Upsample(
(conv): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
)
(3-4): 2 x TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 2560, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(2560, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(2560, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 1280, eps=1e-06, affine=True)
(proj_in): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=1280, out_features=1280, bias=False)
(to_v): Linear(in_features=1280, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=1280, out_features=10240, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=5120, out_features=1280, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=768, out_features=1280, bias=False)
(to_v): Linear(in_features=768, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
)
)
(5): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1920, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1920, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=1280, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(1920, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 1280, eps=1e-06, affine=True)
(proj_in): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=1280, out_features=1280, bias=False)
(to_v): Linear(in_features=1280, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=1280, out_features=10240, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=5120, out_features=1280, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=1280, out_features=1280, bias=False)
(to_k): Linear(in_features=768, out_features=1280, bias=False)
(to_v): Linear(in_features=768, out_features=1280, bias=False)
(to_out): Sequential(
(0): Linear(in_features=1280, out_features=1280, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((1280,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(1280, 1280, kernel_size=(1, 1), stride=(1, 1))
)
(2): Upsample(
(conv): Conv2d(1280, 1280, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
)
(6): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1920, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1920, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=640, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(1920, 640, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 640, eps=1e-06, affine=True)
(proj_in): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=640, out_features=640, bias=False)
(to_v): Linear(in_features=640, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=640, out_features=5120, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=2560, out_features=640, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=768, out_features=640, bias=False)
(to_v): Linear(in_features=768, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
)
)
(7): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 1280, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(1280, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=640, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(1280, 640, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 640, eps=1e-06, affine=True)
(proj_in): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=640, out_features=640, bias=False)
(to_v): Linear(in_features=640, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=640, out_features=5120, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=2560, out_features=640, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=768, out_features=640, bias=False)
(to_v): Linear(in_features=768, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
)
)
(8): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 960, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(960, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=640, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(960, 640, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 640, eps=1e-06, affine=True)
(proj_in): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=640, out_features=640, bias=False)
(to_v): Linear(in_features=640, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=640, out_features=5120, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=2560, out_features=640, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=640, out_features=640, bias=False)
(to_k): Linear(in_features=768, out_features=640, bias=False)
(to_v): Linear(in_features=768, out_features=640, bias=False)
(to_out): Sequential(
(0): Linear(in_features=640, out_features=640, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((640,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(640, 640, kernel_size=(1, 1), stride=(1, 1))
)
(2): Upsample(
(conv): Conv2d(640, 640, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
)
(9): TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 960, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(960, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=320, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(960, 320, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 320, eps=1e-06, affine=True)
(proj_in): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=320, out_features=320, bias=False)
(to_v): Linear(in_features=320, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=320, out_features=2560, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=1280, out_features=320, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=768, out_features=320, bias=False)
(to_v): Linear(in_features=768, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
)
)
(10-11): 2 x TimestepEmbedSequential(
(0): ResBlock(
(in_layers): Sequential(
(0): GroupNorm32(32, 640, eps=1e-05, affine=True)
(1): SiLU()
(2): Conv2d(640, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(h_upd): Identity()
(x_upd): Identity()
(emb_layers): Sequential(
(0): SiLU()
(1): Linear(in_features=1280, out_features=320, bias=True)
)
(out_layers): Sequential(
(0): GroupNorm32(32, 320, eps=1e-05, affine=True)
(1): SiLU()
(2): Dropout(p=0, inplace=False)
(3): Conv2d(320, 320, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
)
(skip_connection): Conv2d(640, 320, kernel_size=(1, 1), stride=(1, 1))
)
(1): SpatialTransformer(
(norm): GroupNorm(32, 320, eps=1e-06, affine=True)
(proj_in): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
(transformer_blocks): ModuleList(
(0): BasicTransformerBlock(
(attn1): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=320, out_features=320, bias=False)
(to_v): Linear(in_features=320, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(ff): FeedForward(
(net): Sequential(
(0): GEGLU(
(proj): Linear(in_features=320, out_features=2560, bias=True)
)
(1): Dropout(p=0.0, inplace=False)
(2): Linear(in_features=1280, out_features=320, bias=True)
)
)
(attn2): CrossAttention(
(to_q): Linear(in_features=320, out_features=320, bias=False)
(to_k): Linear(in_features=768, out_features=320, bias=False)
(to_v): Linear(in_features=768, out_features=320, bias=False)
(to_out): Sequential(
(0): Linear(in_features=320, out_features=320, bias=True)
(1): Dropout(p=0.0, inplace=False)
)
)
(norm1): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm2): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
(norm3): LayerNorm((320,), eps=1e-05, elementwise_affine=True)
)
)
(proj_out): Conv2d(320, 320, kernel_size=(1, 1), stride=(1, 1))
)
)
)

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AIGC笔记--Stable Diffusion源码剖析之UNetModel

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