| | import torch |
| | import torch.nn as nn |
| | from transformers import CLIPConfig, CLIPVisionModel, PreTrainedModel |
| |
|
| | class StableDiffusionSafetyChecker(PreTrainedModel): |
| | config_class = CLIPConfig |
| |
|
| | 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.register_buffer("concept_embeds", torch.ones(17, config.projection_dim)) |
| | self.register_buffer("special_care_embeds", torch.ones(3, config.projection_dim)) |
| | |
| | self.register_buffer("concept_embeds_weights", torch.ones(17)) |
| | self.register_buffer("special_care_embeds_weights", torch.ones(3)) |
| |
|
| | @torch.no_grad() |
| | def forward(self, clip_input, images): |
| | pooled_output = self.vision_model(clip_input)[1] |
| | image_embeds = self.visual_projection(pooled_output) |
| | image_embeds = image_embeds / image_embeds.norm(p=2, dim=-1, keepdim=True) |
| |
|
| | |
| | special_cos_dist = torch.mm(image_embeds, self.special_care_embeds.t()) |
| | cos_dist = torch.mm(image_embeds, self.concept_embeds.t()) |
| |
|
| | has_nsfw_concepts = [] |
| | for i in range(image_embeds.shape[0]): |
| | concept_idx = (cos_dist[i] > self.concept_embeds_weights).any().item() |
| | has_nsfw_concepts.append(concept_idx) |
| | if concept_idx: |
| | images[i] = torch.zeros_like(images[i]) |
| | |
| | return images, has_nsfw_concepts |