File size: 5,463 Bytes
95995fe
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np
import torch
import torch.nn as nn
from transformers import CLIPConfig, CLIPVisionModel, PreTrainedModel


def cosine_distance(image_embeds, text_embeds):
    normalized_image_embeds = nn.functional.normalize(image_embeds)
    normalized_text_embeds = nn.functional.normalize(text_embeds)
    return torch.mm(normalized_image_embeds, normalized_text_embeds.t())


class StableDiffusionSafetyChecker(PreTrainedModel):
    config_class = CLIPConfig

    _no_split_modules = ["CLIPEncoderLayer"]

    def __init__(self, config: CLIPConfig):
        super().__init__(config)

        self.vision_model = CLIPVisionModel(config.vision_config)
        self.visual_projection = nn.Linear(
            config.vision_config.hidden_size, config.projection_dim, bias=False
        )

        self.concept_embeds = nn.Parameter(
            torch.ones(17, config.projection_dim), requires_grad=False
        )
        self.special_care_embeds = nn.Parameter(
            torch.ones(3, config.projection_dim), requires_grad=False
        )

        self.concept_embeds_weights = nn.Parameter(torch.ones(17), requires_grad=False)
        self.special_care_embeds_weights = nn.Parameter(
            torch.ones(3), requires_grad=False
        )

    @torch.no_grad()
    def forward(self, clip_input, images):
        pooled_output = self.vision_model(clip_input)[1]  # pooled_output
        image_embeds = self.visual_projection(pooled_output)

        # we always cast to float32 as this does not cause significant overhead and is compatible with bfloat16
        special_cos_dist = (
            cosine_distance(image_embeds, self.special_care_embeds)
            .cpu()
            .float()
            .numpy()
        )
        cos_dist = (
            cosine_distance(image_embeds, self.concept_embeds).cpu().float().numpy()
        )

        result = []
        batch_size = image_embeds.shape[0]
        for i in range(batch_size):
            result_img = {
                "special_scores": {},
                "special_care": [],
                "concept_scores": {},
                "bad_concepts": [],
            }

            # increase this value to create a stronger `nfsw` filter
            # at the cost of increasing the possibility of filtering benign images
            adjustment = 0.0

            for concept_idx in range(len(special_cos_dist[0])):
                concept_cos = special_cos_dist[i][concept_idx]
                concept_threshold = self.special_care_embeds_weights[concept_idx].item()
                result_img["special_scores"][concept_idx] = round(
                    concept_cos - concept_threshold + adjustment, 3
                )
                if result_img["special_scores"][concept_idx] > 0:
                    result_img["special_care"].append(
                        {concept_idx, result_img["special_scores"][concept_idx]}
                    )
                    adjustment = 0.01

            for concept_idx in range(len(cos_dist[0])):
                concept_cos = cos_dist[i][concept_idx]
                concept_threshold = self.concept_embeds_weights[concept_idx].item()
                result_img["concept_scores"][concept_idx] = round(
                    concept_cos - concept_threshold + adjustment, 3
                )
                if result_img["concept_scores"][concept_idx] > 0:
                    result_img["bad_concepts"].append(concept_idx)

            result.append(result_img)

        has_nsfw_concepts = [len(res["bad_concepts"]) > 0 for res in result]

        return has_nsfw_concepts

    @torch.no_grad()
    def forward_onnx(self, clip_input: torch.FloatTensor, images: torch.FloatTensor):
        pooled_output = self.vision_model(clip_input)[1]  # pooled_output
        image_embeds = self.visual_projection(pooled_output)

        special_cos_dist = cosine_distance(image_embeds, self.special_care_embeds)
        cos_dist = cosine_distance(image_embeds, self.concept_embeds)

        # increase this value to create a stronger `nsfw` filter
        # at the cost of increasing the possibility of filtering benign images
        adjustment = 0.0

        special_scores = (
            special_cos_dist - self.special_care_embeds_weights + adjustment
        )
        # special_scores = special_scores.round(decimals=3)
        special_care = torch.any(special_scores > 0, dim=1)
        special_adjustment = special_care * 0.01
        special_adjustment = special_adjustment.unsqueeze(1).expand(
            -1, cos_dist.shape[1]
        )

        concept_scores = (cos_dist - self.concept_embeds_weights) + special_adjustment
        # concept_scores = concept_scores.round(decimals=3)
        has_nsfw_concepts = torch.any(concept_scores > 0, dim=1)

        images[has_nsfw_concepts] = 0.0  # black image

        return images, has_nsfw_concepts