File size: 6,998 Bytes
3ae7741
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
import math
import copy
import random
import torch
import numpy as np
import torch.nn as nn
import torch.nn.functional as F

from safetensors.torch import save_file
from safetensors import safe_open
from torch.nn.parameter import Parameter

from depth_anything_v2_metric.depth_anything_v2.dpt import DepthAnythingV2

class _LoRA_qkv(nn.Module):
    """In Sam it is implemented as
    self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
    B, N, C = x.shape
    qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, self.head_dim).permute(2, 0, 3, 1, 4)
    q, k, v = qkv.unbind(0)
    """

    def __init__(
        self,
        qkv: nn.Module,
        linear_a_q: nn.Module,
        linear_b_q: nn.Module,
        linear_a_v: nn.Module,
        linear_b_v: nn.Module,
    ):
        super().__init__()
        self.qkv = qkv
        self.linear_a_q = linear_a_q
        self.linear_b_q = linear_b_q
        self.linear_a_v = linear_a_v
        self.linear_b_v = linear_b_v
        self.dim = qkv.in_features
        self.w_identity = torch.eye(qkv.in_features)

    def forward(self, x):
        qkv = self.qkv(x)  # B,N,3*org_C
        new_q = self.linear_b_q(self.linear_a_q(x))
        new_v = self.linear_b_v(self.linear_a_v(x))
        
        qkv[:, :, : self.dim] += new_q
        qkv[:, :, -self.dim:] += new_v
        return qkv

class LoRA(nn.Module):
    def __init__(self, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)

    def save_fc_parameters(self, filename: str) -> None:
        r"""Only safetensors is supported now.

        pip install safetensor if you do not have one installed yet.
        """
        assert filename.endswith(".safetensors")
        _in = self.lora_vit.head.in_features
        _out = self.lora_vit.head.out_features
        fc_tensors = {f"fc_{_in}in_{_out}out": self.lora_vit.head.weight}
        save_file(fc_tensors, filename)

    def load_fc_parameters(self, filename: str) -> None:
        r"""Only safetensors is supported now.

        pip install safetensor if you do not have one installed yet.
        """

        assert filename.endswith(".safetensors")
        _in = self.lora_vit.head.in_features
        _out = self.lora_vit.head.out_features
        with safe_open(filename, framework="pt") as f:
            saved_key = f"fc_{_in}in_{_out}out"
            try:
                saved_tensor = f.get_tensor(saved_key)
                self.lora_vit.head.weight = Parameter(saved_tensor)
            except ValueError:
                print("this fc weight is not for this model")

    def save_lora_parameters(self, filename: str) -> None:
        r"""Only safetensors is supported now.

        pip install safetensor if you do not have one installed yet.
        
        save both lora and fc parameters.
        """

        assert filename.endswith(".safetensors")

        num_layer = len(self.w_As)  # actually, it is half
        a_tensors = {f"w_a_{i:03d}": self.w_As[i].weight for i in range(num_layer)}
        b_tensors = {f"w_b_{i:03d}": self.w_Bs[i].weight for i in range(num_layer)}
        
        _in = self.lora_vit.head.in_features
        _out = self.lora_vit.head.out_features
        fc_tensors = {f"fc_{_in}in_{_out}out": self.lora_vit.head.weight}
        
        merged_dict = {**a_tensors, **b_tensors, **fc_tensors}
        save_file(merged_dict, filename)

    def load_lora_parameters(self, filename: str) -> None:
        r"""Only safetensors is supported now.

        pip install safetensor if you do not have one installed yet.\
            
        load both lora and fc parameters.
        """

        assert filename.endswith(".safetensors")

        with safe_open(filename, framework="pt") as f:
            for i, w_A_linear in enumerate(self.w_As):
                saved_key = f"w_a_{i:03d}"
                saved_tensor = f.get_tensor(saved_key)
                w_A_linear.weight = Parameter(saved_tensor)

            for i, w_B_linear in enumerate(self.w_Bs):
                saved_key = f"w_b_{i:03d}"
                saved_tensor = f.get_tensor(saved_key)
                w_B_linear.weight = Parameter(saved_tensor)
                
            _in = self.lora_vit.head.in_features
            _out = self.lora_vit.head.out_features
            saved_key = f"fc_{_in}in_{_out}out"
            try:
                saved_tensor = f.get_tensor(saved_key)
                self.lora_vit.head.weight = Parameter(saved_tensor)
            except ValueError:
                print("this fc weight is not for this model")

    def reset_parameters(self) -> None:
        for w_A in self.w_As:
            nn.init.kaiming_uniform_(w_A.weight, a=math.sqrt(5))
        for w_B in self.w_Bs:
            nn.init.zeros_(w_B.weight)

class LoRA_Depth_Anything_v2(LoRA):
    """Applies low-rank adaptation to a Depth Anything model's image encoder.

    Args:
        sam_model: a vision transformer model, see base_vit.py
        r: rank of LoRA
        num_classes: how many classes the model output, default to the vit model
        lora_layer: which layer we apply LoRA.

    Examples::
        >>> model = ViT('B_16_imagenet1k')
        >>> lora_model = LoRA_ViT(model, r=4)
        >>> preds = lora_model(img)
        >>> print(preds.shape)
        torch.Size([1, 1000])
    """

    def __init__(self, da_model: DepthAnythingV2, r: int, lora_layer=None):
        super(LoRA_Depth_Anything_v2, self).__init__()

        assert r > 0
        # base_vit_dim = sam_model.image_encoder.patch_embed.proj.out_channels
        # dim = base_vit_dim
        if lora_layer:
            self.lora_layer = lora_layer
        else:
            self.lora_layer = list(range(len(da_model.pretrained.blocks)))
        # create for storage, then we can init them or load weights
        self.w_As = []  # These are linear layers
        self.w_Bs = []

        # lets freeze first
        for param in da_model.pretrained.parameters():
            param.requires_grad = False

        # Here, we do the surgery
        for t_layer_i, blk in enumerate(da_model.pretrained.blocks):
            # If we only want few lora layer instead of all
            if t_layer_i not in self.lora_layer:
                continue
            w_qkv_linear = blk.attn.qkv
            self.dim = w_qkv_linear.in_features
            w_a_linear_q = nn.Linear(self.dim, r, bias=False)
            w_b_linear_q = nn.Linear(r, self.dim, bias=False)
            w_a_linear_v = nn.Linear(self.dim, r, bias=False)
            w_b_linear_v = nn.Linear(r, self.dim, bias=False)
            self.w_As.append(w_a_linear_q)
            self.w_Bs.append(w_b_linear_q)
            self.w_As.append(w_a_linear_v)
            self.w_Bs.append(w_b_linear_v)
            blk.attn.qkv = _LoRA_qkv(
                w_qkv_linear,
                w_a_linear_q,
                w_b_linear_q,
                w_a_linear_v,
                w_b_linear_v,
            )
        self.reset_parameters()
        
        self.lora_vit = da_model