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| # 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) | |
| 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 | |
| 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 |