Xu CAO e458a467d6
[Project] Support CAT-Seg from CVPR2023 (#3098)
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## Motivation

Support CAT-Seg open-vocabulary semantic segmentation (CVPR2023).

## Modification

Support CAT-Seg open-vocabulary semantic segmentation (CVPR2023).
- [x] Support CAT-Seg model training.
- [x] CLIP model based `backbone` (R101 & Swin-B), aggregation layers
based `neck`, and `decoder` head.
  - [x] Provide customized coco-stuff164k_384x384 training configs.
- [x] Language model supports for `open vocabulary` (OV) tasks. 
  - [x] Support CLIP-based pretrained language model (LM) inference.
  - [x] Add commonly used prompts templates. 
- [x] Add README tutorials.
- [x] Add zero-shot testing scripts.

**Working on the following tasks.**
- [x] Add unit test.

## BC-breaking (Optional)

Does the modification introduce changes that break the
backward-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the
downstream projects should modify their code to keep compatibility with
this PR.

## Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases
here, and update the documentation.

## Checklist

1. Pre-commit or other linting tools are used to fix the potential lint
issues.
2. The modification is covered by complete unit tests. If not, please
add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects,
this PR should be tested with downstream projects, like MMDet or
MMDet3D.
4. The documentation has been modified accordingly, like docstring or
example tutorials.

---------

Co-authored-by: xiexinch <xiexinch@outlook.com>
2023-08-09 23:57:30 +08:00

764 lines
28 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
import torch
import torch.nn as nn
import torch.nn.functional as F
from mmcv.cnn import build_norm_layer
from mmcv.cnn.bricks.transformer import FFN, build_dropout
from mmengine.model import BaseModule
from mmengine.utils import to_2tuple
from mmseg.registry import MODELS
from ..utils import FullAttention, LinearAttention
class AGWindowMSA(BaseModule):
"""Appearance Guidance Window based multi-head self-attention (W-MSA)
module with relative position bias.
Args:
embed_dims (int): Number of input channels.
appearance_dims (int): Number of appearance guidance feature channels.
num_heads (int): Number of attention heads.
window_size (tuple[int]): The height and width of the window.
qkv_bias (bool, optional): If True, add a learnable bias to q, k, v.
Default: True.
qk_scale (float | None, optional): Override default qk scale of
head_dim ** -0.5 if set. Default: None.
attn_drop_rate (float, optional): Dropout ratio of attention weight.
Default: 0.0
proj_drop_rate (float, optional): Dropout ratio of output. Default: 0.
init_cfg (dict | None, optional): The Config for initialization.
Default: None.
"""
def __init__(self,
embed_dims,
appearance_dims,
num_heads,
window_size,
qkv_bias=True,
qk_scale=None,
attn_drop_rate=0.,
proj_drop_rate=0.,
init_cfg=None):
super().__init__(init_cfg=init_cfg)
self.embed_dims = embed_dims
self.appearance_dims = appearance_dims
self.window_size = window_size # Wh, Ww
self.num_heads = num_heads
head_embed_dims = embed_dims // num_heads
self.scale = qk_scale or head_embed_dims**-0.5
# About 2x faster than original impl
Wh, Ww = self.window_size
rel_index_coords = self.double_step_seq(2 * Ww - 1, Wh, 1, Ww)
rel_position_index = rel_index_coords + rel_index_coords.T
rel_position_index = rel_position_index.flip(1).contiguous()
self.register_buffer('relative_position_index', rel_position_index)
self.qk = nn.Linear(
embed_dims + appearance_dims, embed_dims * 2, bias=qkv_bias)
self.v = nn.Linear(embed_dims, embed_dims, bias=qkv_bias)
self.attn_drop = nn.Dropout(attn_drop_rate)
self.proj = nn.Linear(embed_dims, embed_dims)
self.proj_drop = nn.Dropout(proj_drop_rate)
self.softmax = nn.Softmax(dim=-1)
def forward(self, x, mask=None):
"""
Args:
x (tensor): input features with shape of (num_windows*B, N, C),
C = embed_dims + appearance_dims.
mask (tensor | None, Optional): mask with shape of (num_windows,
Wh*Ww, Wh*Ww), value should be between (-inf, 0].
"""
B, N, _ = x.shape
qk = self.qk(x).reshape(B, N, 2, self.num_heads,
self.embed_dims // self.num_heads).permute(
2, 0, 3, 1,
4) # 2 B NUM_HEADS N embed_dims//NUM_HEADS
v = self.v(x[:, :, :self.embed_dims]).reshape(
B, N, self.num_heads, self.embed_dims // self.num_heads).permute(
0, 2, 1, 3) # B NUM_HEADS N embed_dims//NUM_HEADS
# make torchscript happy (cannot use tensor as tuple)
q, k = qk[0], qk[1]
q = q * self.scale
attn = (q @ k.transpose(-2, -1))
if mask is not None:
nW = mask.shape[0]
attn = attn.view(B // nW, nW, self.num_heads, N,
N) + mask.unsqueeze(1).unsqueeze(0)
attn = attn.view(-1, self.num_heads, N, N)
attn = self.softmax(attn)
attn = self.attn_drop(attn)
x = (attn @ v).transpose(1, 2).reshape(B, N, self.embed_dims)
x = self.proj(x)
x = self.proj_drop(x)
return x
@staticmethod
def double_step_seq(step1, len1, step2, len2):
"""Double step sequence."""
seq1 = torch.arange(0, step1 * len1, step1)
seq2 = torch.arange(0, step2 * len2, step2)
return (seq1[:, None] + seq2[None, :]).reshape(1, -1)
class AGShiftWindowMSA(BaseModule):
"""Appearance Guidance Shifted Window Multihead Self-Attention Module.
Args:
embed_dims (int): Number of input channels.
appearance_dims (int): Number of appearance guidance channels
num_heads (int): Number of attention heads.
window_size (int): The height and width of the window.
shift_size (int, optional): The shift step of each window towards
right-bottom. If zero, act as regular window-msa. Defaults to 0.
qkv_bias (bool, optional): If True, add a learnable bias to q, k, v.
Default: True
qk_scale (float | None, optional): Override default qk scale of
head_dim ** -0.5 if set. Defaults: None.
attn_drop_rate (float, optional): Dropout ratio of attention weight.
Defaults: 0.
proj_drop_rate (float, optional): Dropout ratio of output.
Defaults: 0.
dropout_layer (dict, optional): The dropout_layer used before output.
Defaults: dict(type='DropPath', drop_prob=0.).
init_cfg (dict, optional): The extra config for initialization.
Default: None.
"""
def __init__(self,
embed_dims,
appearance_dims,
num_heads,
window_size,
shift_size=0,
qkv_bias=True,
qk_scale=None,
attn_drop_rate=0,
proj_drop_rate=0,
dropout_layer=dict(type='DropPath', drop_prob=0.),
init_cfg=None):
super().__init__(init_cfg=init_cfg)
self.window_size = window_size
self.shift_size = shift_size
assert 0 <= self.shift_size < self.window_size
self.w_msa = AGWindowMSA(
embed_dims=embed_dims,
appearance_dims=appearance_dims,
num_heads=num_heads,
window_size=to_2tuple(window_size),
qkv_bias=qkv_bias,
qk_scale=qk_scale,
attn_drop_rate=attn_drop_rate,
proj_drop_rate=proj_drop_rate,
init_cfg=None)
self.drop = build_dropout(dropout_layer)
def forward(self, query, hw_shape):
"""
Args:
query: The input query.
hw_shape: The shape of the feature height and width.
"""
B, L, C = query.shape
H, W = hw_shape
assert L == H * W, 'input feature has wrong size'
query = query.view(B, H, W, C)
# pad feature maps to multiples of window size
pad_r = (self.window_size - W % self.window_size) % self.window_size
pad_b = (self.window_size - H % self.window_size) % self.window_size
query = F.pad(query, (0, 0, 0, pad_r, 0, pad_b))
H_pad, W_pad = query.shape[1], query.shape[2]
# cyclic shift
if self.shift_size > 0:
shifted_query = torch.roll(
query,
shifts=(-self.shift_size, -self.shift_size),
dims=(1, 2))
# calculate attention mask for SW-MSA
img_mask = torch.zeros((1, H_pad, W_pad, 1), device=query.device)
h_slices = (slice(0, -self.window_size),
slice(-self.window_size,
-self.shift_size), slice(-self.shift_size, None))
w_slices = (slice(0, -self.window_size),
slice(-self.window_size,
-self.shift_size), slice(-self.shift_size, None))
cnt = 0
for h in h_slices:
for w in w_slices:
img_mask[:, h, w, :] = cnt
cnt += 1
# nW, window_size, window_size, 1
mask_windows = self.window_partition(img_mask)
mask_windows = mask_windows.view(
-1, self.window_size * self.window_size)
attn_mask = mask_windows.unsqueeze(1) - mask_windows.unsqueeze(2)
attn_mask = attn_mask.masked_fill(attn_mask != 0,
float(-100.0)).masked_fill(
attn_mask == 0, float(0.0))
else:
shifted_query = query
attn_mask = None
# nW*B, window_size, window_size, C
query_windows = self.window_partition(shifted_query)
# nW*B, window_size*window_size, C
query_windows = query_windows.view(-1, self.window_size**2, C)
# W-MSA/SW-MSA (nW*B, window_size*window_size, C)
attn_windows = self.w_msa(query_windows, mask=attn_mask)
# merge windows
attn_windows = attn_windows.view(-1, self.window_size,
self.window_size,
self.w_msa.embed_dims)
# B H' W' self.w_msa.embed_dims
shifted_x = self.window_reverse(attn_windows, H_pad, W_pad)
# reverse cyclic shift
if self.shift_size > 0:
x = torch.roll(
shifted_x,
shifts=(self.shift_size, self.shift_size),
dims=(1, 2))
else:
x = shifted_x
if pad_r > 0 or pad_b:
x = x[:, :H, :W, :].contiguous()
x = x.view(B, H * W, self.w_msa.embed_dims)
x = self.drop(x)
return x
def window_reverse(self, windows, H, W):
"""
Args:
windows: (num_windows*B, window_size, window_size, C)
H (int): Height of image
W (int): Width of image
Returns:
x: (B, H, W, C)
"""
window_size = self.window_size
B = int(windows.shape[0] / (H * W / window_size / window_size))
x = windows.view(B, H // window_size, W // window_size, window_size,
window_size, -1)
x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, H, W, -1)
return x
def window_partition(self, x):
"""
Args:
x: (B, H, W, C)
Returns:
windows: (num_windows*B, window_size, window_size, C)
"""
B, H, W, C = x.shape
window_size = self.window_size
x = x.view(B, H // window_size, window_size, W // window_size,
window_size, C)
windows = x.permute(0, 1, 3, 2, 4, 5).contiguous()
windows = windows.view(-1, window_size, window_size, C)
return windows
class AGSwinBlock(BaseModule):
"""Appearance Guidance Swin Transformer Block.
Args:
embed_dims (int): The feature dimension.
appearance_dims (int): The appearance guidance dimension.
num_heads (int): Parallel attention heads.
mlp_ratios (int): The hidden dimension ratio w.r.t. embed_dims
for FFNs.
window_size (int, optional): The local window scale.
Default: 7.
shift (bool, optional): whether to shift window or not.
Default False.
qkv_bias (bool, optional): enable bias for qkv if True.
Default: True.
qk_scale (float | None, optional): Override default qk scale of
head_dim ** -0.5 if set. Default: None.
drop_rate (float, optional): Dropout rate. Default: 0.
attn_drop_rate (float, optional): Attention dropout rate.
Default: 0.
drop_path_rate (float, optional): Stochastic depth rate.
Default: 0.
act_cfg (dict, optional): The config dict of activation function.
Default: dict(type='GELU').
norm_cfg (dict, optional): The config dict of normalization.
Default: dict(type='LN').
init_cfg (dict | list | None, optional): The init config.
Default: None.
"""
def __init__(self,
embed_dims,
appearance_dims,
num_heads,
mlp_ratios=4,
window_size=7,
shift=False,
qkv_bias=True,
qk_scale=None,
drop_rate=0.,
attn_drop_rate=0.,
drop_path_rate=0.,
act_cfg=dict(type='GELU'),
norm_cfg=dict(type='LN'),
init_cfg=None):
super().__init__(init_cfg=init_cfg)
self.norm1 = build_norm_layer(norm_cfg, embed_dims)[1]
self.attn = AGShiftWindowMSA(
embed_dims=embed_dims,
appearance_dims=appearance_dims,
num_heads=num_heads,
window_size=window_size,
shift_size=window_size // 2 if shift else 0,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
attn_drop_rate=attn_drop_rate,
proj_drop_rate=drop_rate,
dropout_layer=dict(type='DropPath', drop_prob=drop_path_rate),
init_cfg=None)
self.norm2 = build_norm_layer(norm_cfg, embed_dims)[1]
self.ffn = FFN(
embed_dims=embed_dims,
feedforward_channels=embed_dims * mlp_ratios,
num_fcs=2,
ffn_drop=drop_rate,
dropout_layer=dict(type='DropPath', drop_prob=drop_path_rate),
act_cfg=act_cfg,
add_identity=True,
init_cfg=None)
def forward(self, inputs, hw_shape):
"""
Args:
inputs (list[Tensor]): appearance_guidance (B, H, W, C);
x (B, L, C)
hw_shape (tuple[int]): shape of feature.
"""
x, appearance_guidance = inputs
B, L, C = x.shape
H, W = hw_shape
assert L == H * W, 'input feature has wrong size'
identity = x
x = self.norm1(x)
# appearance guidance
x = x.view(B, H, W, C)
if appearance_guidance is not None:
x = torch.cat([x, appearance_guidance], dim=-1).flatten(1, 2)
x = self.attn(x, hw_shape)
x = x + identity
identity = x
x = self.norm2(x)
x = self.ffn(x, identity=identity)
return x
@MODELS.register_module()
class SpatialAggregateLayer(BaseModule):
"""Spatial aggregation layer of CAT-Seg.
Args:
embed_dims (int): The feature dimension.
appearance_dims (int): The appearance guidance dimension.
num_heads (int): Parallel attention heads.
mlp_ratios (int): The hidden dimension ratio w.r.t. embed_dims
for FFNs.
window_size (int, optional): The local window scale. Default: 7.
qk_scale (float | None, optional): Override default qk scale of
head_dim ** -0.5 if set. Default: None.
init_cfg (dict | list | None, optional): The init config.
Default: None.
"""
def __init__(self,
embed_dims,
appearance_dims,
num_heads,
mlp_ratios,
window_size=7,
qk_scale=None,
init_cfg=None):
super().__init__(init_cfg=init_cfg)
self.block_1 = AGSwinBlock(
embed_dims,
appearance_dims,
num_heads,
mlp_ratios,
window_size=window_size,
shift=False,
qk_scale=qk_scale)
self.block_2 = AGSwinBlock(
embed_dims,
appearance_dims,
num_heads,
mlp_ratios,
window_size=window_size,
shift=True,
qk_scale=qk_scale)
self.guidance_norm = nn.LayerNorm(
appearance_dims) if appearance_dims > 0 else None
def forward(self, x, appearance_guidance):
"""
Args:
x (torch.Tensor): B C T H W.
appearance_guidance (torch.Tensor): B C H W.
"""
B, C, T, H, W = x.shape
x = x.permute(0, 2, 3, 4, 1).flatten(0, 1).flatten(1, 2) # BT, HW, C
if appearance_guidance is not None:
appearance_guidance = appearance_guidance.repeat(
T, 1, 1, 1).permute(0, 2, 3, 1) # BT, HW, C
appearance_guidance = self.guidance_norm(appearance_guidance)
else:
assert self.appearance_dims == 0
x = self.block_1((x, appearance_guidance), (H, W))
x = self.block_2((x, appearance_guidance), (H, W))
x = x.transpose(1, 2).reshape(B, T, C, -1)
x = x.transpose(1, 2).reshape(B, C, T, H, W)
return x
class AttentionLayer(nn.Module):
"""Attention layer for ClassAggregration of CAT-Seg.
Source: https://github.com/KU-CVLAB/CAT-Seg/blob/main/cat_seg/modeling/transformer/model.py#L310 # noqa
"""
def __init__(self,
hidden_dim,
guidance_dim,
nheads=8,
attention_type='linear'):
super().__init__()
self.nheads = nheads
self.q = nn.Linear(hidden_dim + guidance_dim, hidden_dim)
self.k = nn.Linear(hidden_dim + guidance_dim, hidden_dim)
self.v = nn.Linear(hidden_dim, hidden_dim)
if attention_type == 'linear':
self.attention = LinearAttention()
elif attention_type == 'full':
self.attention = FullAttention()
else:
raise NotImplementedError
def forward(self, x, guidance=None):
"""
Args:
x: B*H_p*W_p, T, C
guidance: B*H_p*W_p, T, C
"""
B, L, _ = x.shape
q = self.q(torch.cat([x, guidance],
dim=-1)) if guidance is not None else self.q(x)
k = self.k(torch.cat([x, guidance],
dim=-1)) if guidance is not None else self.k(x)
v = self.v(x)
q = q.reshape(B, L, self.nheads, -1)
k = k.reshape(B, L, self.nheads, -1)
v = v.reshape(B, L, self.nheads, -1)
out = self.attention(q, k, v)
out = out.reshape(B, L, -1)
return out
@MODELS.register_module()
class ClassAggregateLayer(BaseModule):
"""Class aggregation layer of CAT-Seg.
Args:
hidden_dims (int): The feature dimension.
guidance_dims (int): The appearance guidance dimension.
num_heads (int): Parallel attention heads.
attention_type (str): Type of attention layer. Default: 'linear'.
pooling_size (tuple[int] | list[int]): Pooling size.
init_cfg (dict | list | None, optional): The init config.
Default: None.
"""
def __init__(
self,
hidden_dims=64,
guidance_dims=64,
num_heads=8,
attention_type='linear',
pooling_size=(4, 4),
init_cfg=None,
):
super().__init__(init_cfg=init_cfg)
self.pool = nn.AvgPool2d(pooling_size)
self.attention = AttentionLayer(
hidden_dims,
guidance_dims,
nheads=num_heads,
attention_type=attention_type)
self.MLP = FFN(
embed_dims=hidden_dims,
feedforward_channels=hidden_dims * 4,
num_fcs=2)
self.norm1 = nn.LayerNorm(hidden_dims)
self.norm2 = nn.LayerNorm(hidden_dims)
def pool_features(self, x):
"""Intermediate pooling layer for computational efficiency.
Args:
x: B, C, T, H, W
"""
B, C, T, H, W = x.shape
x = x.transpose(1, 2).reshape(-1, C, H, W)
x = self.pool(x)
*_, H_, W_ = x.shape
x = x.reshape(B, T, C, H_, W_).transpose(1, 2)
return x
def forward(self, x, guidance):
"""
Args:
x: B, C, T, H, W
guidance: B, T, C
"""
B, C, T, H, W = x.size()
x_pool = self.pool_features(x)
*_, H_pool, W_pool = x_pool.size()
x_pool = x_pool.permute(0, 3, 4, 2, 1).reshape(-1, T, C)
# B*H_p*W_p T C
if guidance is not None:
guidance = guidance.repeat(H_pool * W_pool, 1, 1)
x_pool = x_pool + self.attention(self.norm1(x_pool),
guidance) # Attention
x_pool = x_pool + self.MLP(self.norm2(x_pool)) # MLP
x_pool = x_pool.reshape(B, H_pool * W_pool, T,
C).permute(0, 2, 3, 1).reshape(
B, T, C, H_pool,
W_pool).flatten(0, 1) # BT C H_p W_p
x_pool = F.interpolate(
x_pool, size=(H, W), mode='bilinear', align_corners=True)
x_pool = x_pool.reshape(B, T, C, H, W).transpose(1, 2) # B C T H W
x = x + x_pool # Residual
return x
@MODELS.register_module()
class AggregatorLayer(BaseModule):
"""Single Aggregator Layer of CAT-Seg."""
def __init__(self,
embed_dims=64,
text_guidance_dims=512,
appearance_guidance_dims=512,
num_heads=4,
mlp_ratios=4,
window_size=7,
attention_type='linear',
pooling_size=(2, 2),
init_cfg=None) -> None:
super().__init__(init_cfg=init_cfg)
self.spatial_agg = SpatialAggregateLayer(
embed_dims,
appearance_guidance_dims,
num_heads=num_heads,
mlp_ratios=mlp_ratios,
window_size=window_size)
self.class_agg = ClassAggregateLayer(
embed_dims,
text_guidance_dims,
num_heads=num_heads,
attention_type=attention_type,
pooling_size=pooling_size)
def forward(self, x, appearance_guidance, text_guidance):
"""
Args:
x: B C T H W
"""
x = self.spatial_agg(x, appearance_guidance)
x = self.class_agg(x, text_guidance)
return x
@MODELS.register_module()
class CATSegAggregator(BaseModule):
"""CATSeg Aggregator.
This Aggregator is the mmseg implementation of
`CAT-Seg <https://arxiv.org/abs/2303.11797>`_.
Args:
text_guidance_dim (int): Text guidance dimensions. Default: 512.
text_guidance_proj_dim (int): Text guidance projection dimensions.
Default: 128.
appearance_guidance_dim (int): Appearance guidance dimensions.
Default: 512.
appearance_guidance_proj_dim (int): Appearance guidance projection
dimensions. Default: 128.
num_layers (int): Aggregator layer number. Default: 4.
num_heads (int): Attention layer head number. Default: 4.
embed_dims (int): Input feature dimensions. Default: 128.
pooling_size (tuple | list): Pooling size of the class aggregator
layer. Default: (6, 6).
mlp_ratios (int): The hidden dimension ratio w.r.t. input dimension.
Default: 4.
window_size (int): Swin block window size. Default:12.
attention_type (str): Attention type of class aggregator layer.
Default:'linear'.
prompt_channel (int): Prompt channels. Default: 80.
"""
def __init__(self,
text_guidance_dim=512,
text_guidance_proj_dim=128,
appearance_guidance_dim=512,
appearance_guidance_proj_dim=128,
num_layers=4,
num_heads=4,
embed_dims=128,
pooling_size=(6, 6),
mlp_ratios=4,
window_size=12,
attention_type='linear',
prompt_channel=80,
**kwargs):
super().__init__(**kwargs)
self.num_layers = num_layers
self.embed_dims = embed_dims
self.layers = nn.ModuleList([
AggregatorLayer(
embed_dims=embed_dims,
text_guidance_dims=text_guidance_proj_dim,
appearance_guidance_dims=appearance_guidance_proj_dim,
num_heads=num_heads,
mlp_ratios=mlp_ratios,
window_size=window_size,
attention_type=attention_type,
pooling_size=pooling_size) for _ in range(num_layers)
])
self.conv1 = nn.Conv2d(
prompt_channel, embed_dims, kernel_size=7, stride=1, padding=3)
self.guidance_projection = nn.Sequential(
nn.Conv2d(
appearance_guidance_dim,
appearance_guidance_proj_dim,
kernel_size=3,
stride=1,
padding=1),
nn.ReLU(),
) if appearance_guidance_dim > 0 else None
self.text_guidance_projection = nn.Sequential(
nn.Linear(text_guidance_dim, text_guidance_proj_dim),
nn.ReLU(),
) if text_guidance_dim > 0 else None
def feature_map(self, img_feats, text_feats):
"""Concatenation type cost volume.
For ablation study of cost volume type.
"""
img_feats = F.normalize(img_feats, dim=1) # B C H W
img_feats = img_feats.unsqueeze(2).repeat(1, 1, text_feats.shape[1], 1,
1)
text_feats = F.normalize(text_feats, dim=-1) # B T P C
text_feats = text_feats.mean(dim=-2)
text_feats = F.normalize(text_feats, dim=-1) # B T C
text_feats = text_feats.unsqueeze(-1).unsqueeze(-1).repeat(
1, 1, 1, img_feats.shape[-2], img_feats.shape[-1]).transpose(1, 2)
return torch.cat((img_feats, text_feats), dim=1) # B 2C T H W
def correlation(self, img_feats, text_feats):
"""Correlation of image features and text features."""
img_feats = F.normalize(img_feats, dim=1) # B C H W
text_feats = F.normalize(text_feats, dim=-1) # B T P C
corr = torch.einsum('bchw, btpc -> bpthw', img_feats, text_feats)
return corr
def corr_embed(self, x):
"""Correlation embeddings encoding."""
B = x.shape[0]
corr_embed = x.permute(0, 2, 1, 3, 4).flatten(0, 1)
corr_embed = self.conv1(corr_embed)
corr_embed = corr_embed.reshape(B, -1, self.embed_dims, x.shape[-2],
x.shape[-1]).transpose(1, 2)
return corr_embed
def forward(self, inputs):
"""
Args:
inputs (dict): including the following keys,
'appearance_feat': list[torch.Tensor], w.r.t. out_indices of
`self.feature_extractor`.
'clip_text_feat': the text feature extracted by clip text
encoder.
'clip_text_feat_test': the text feature extracted by clip text
encoder for testing.
'clip_img_feat': the image feature extracted clip image
encoder.
"""
img_feats = inputs['clip_img_feat']
B = img_feats.size(0)
appearance_guidance = inputs[
'appearance_feat'][::-1] # order (out_indices) 2, 1, 0
text_feats = inputs['clip_text_feat'] if self.training else inputs[
'clip_text_feat_test']
text_feats = text_feats.repeat(B, 1, 1, 1)
corr = self.correlation(img_feats, text_feats)
# corr = self.feature_map(img_feats, text_feats)
corr_embed = self.corr_embed(corr)
projected_guidance, projected_text_guidance = None, None
if self.guidance_projection is not None:
projected_guidance = self.guidance_projection(
appearance_guidance[0])
if self.text_guidance_projection is not None:
text_feats = text_feats.mean(dim=-2)
text_feats = text_feats / text_feats.norm(dim=-1, keepdim=True)
projected_text_guidance = self.text_guidance_projection(text_feats)
for layer in self.layers:
corr_embed = layer(corr_embed, projected_guidance,
projected_text_guidance)
return dict(
corr_embed=corr_embed, appearance_feats=appearance_guidance[1:])