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from __future__ import annotations |
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import os, json, re |
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from pathlib import Path |
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from typing import List, Optional |
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import torch |
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import torch.nn as nn |
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import torch.nn.functional as F |
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from PIL import Image |
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try: |
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import open_clip |
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HAS_OPENCLIP = True |
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except Exception: |
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HAS_OPENCLIP = False |
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from transformers import ( |
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AutoModelForCausalLM, AutoTokenizer, |
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CLIPImageProcessor as HFCLIPImageProcessor, |
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CLIPModel as HFCLIPModel, |
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) |
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class PrefixProjector(nn.Module): |
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def __init__(self, in_dim: int, out_dim: int, tokens: int, p_drop: float = 0.05): |
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super().__init__() |
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hidden = max(512, out_dim * 2) |
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self.fc1 = nn.Linear(in_dim, hidden) |
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self.fc2 = nn.Linear(hidden, out_dim * tokens) |
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self.ln = nn.LayerNorm(out_dim) |
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self.tokens = tokens |
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self.drop = nn.Dropout(p_drop) |
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self.alpha = nn.Parameter(torch.tensor(0.5)) |
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nn.init.xavier_uniform_(self.fc1.weight, gain=1.0) |
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nn.init.zeros_(self.fc1.bias) |
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nn.init.xavier_uniform_(self.fc2.weight, gain=0.5) |
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nn.init.zeros_(self.fc2.bias) |
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def forward(self, x: torch.Tensor) -> torch.Tensor: |
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y = F.gelu(self.fc1(x)) |
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y = self.fc2(y).view(x.size(0), self.tokens, -1) |
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y = self.ln(y) |
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y = self.drop(self.alpha * y) |
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return y |
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class CLIPBackend: |
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def __init__(self, repo_or_kind: str, device: str): |
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self.device = device |
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self.repo_or_kind = repo_or_kind |
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if 'BiomedCLIP' in repo_or_kind or 'microsoft/BiomedCLIP-PubMedBERT_256-vit_base_patch16_224' in repo_or_kind: |
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assert HAS_OPENCLIP, "open_clip is required for BiomedCLIP" |
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if not repo_or_kind.startswith('microsoft/'): |
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repo_or_kind = 'microsoft/BiomedCLIP-PubMedBERT_256-vit_base_patch16_224' |
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model_name = f'hf-hub:{repo_or_kind}' |
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self.model, self.preprocess, _ = open_clip.create_model_and_transforms(model_name) |
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self.model = self.model.to(device).eval() |
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self.kind = "open_clip" |
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self.processor = None |
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elif "/" in repo_or_kind and 'pubmed-clip' in repo_or_kind: |
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self.model = HFCLIPModel.from_pretrained(repo_or_kind).to(device).eval() |
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self.processor = HFCLIPImageProcessor.from_pretrained(repo_or_kind) |
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self.kind = "hf_clip" |
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self.preprocess = None |
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elif "/" in repo_or_kind or repo_or_kind.startswith('redlessone/'): |
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assert HAS_OPENCLIP, "open_clip is required for DermLIP" |
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model_name = f"hf-hub:{repo_or_kind}" |
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self.model, self.preprocess, _ = open_clip.create_model_and_transforms(model_name) |
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self.model = self.model.to(device).eval() |
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self.kind = "open_clip" |
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self.processor = None |
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else: |
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try: |
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if 'biomedclip' in repo_or_kind.lower() or 'biomed' in repo_or_kind.lower(): |
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assert HAS_OPENCLIP, "open_clip is required for BiomedCLIP" |
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model_name = "hf-hub:microsoft/BiomedCLIP-PubMedBERT_256-vit_base_patch16_224" |
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self.model, self.preprocess, _ = open_clip.create_model_and_transforms(model_name) |
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self.model = self.model.to(device).eval() |
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self.kind = "open_clip" |
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self.processor = None |
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elif 'dermlip' in repo_or_kind.lower(): |
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assert HAS_OPENCLIP, "open_clip is required for DermLIP" |
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model_name = "hf-hub:redlessone/DermLIP_ViT-B-16" |
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self.model, self.preprocess, _ = open_clip.create_model_and_transforms(model_name) |
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self.model = self.model.to(device).eval() |
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self.kind = "open_clip" |
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self.processor = None |
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elif 'pubmed' in repo_or_kind.lower(): |
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repo_name = "flaviagiammarino/pubmed-clip-vit-base-patch32" |
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self.model = HFCLIPModel.from_pretrained(repo_name).to(device).eval() |
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self.processor = HFCLIPImageProcessor.from_pretrained(repo_name) |
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self.kind = "hf_clip" |
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self.preprocess = None |
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else: |
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raise ValueError(f"Unknown model type: {repo_or_kind}") |
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except Exception as e: |
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try: |
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self.model = HFCLIPModel.from_pretrained(repo_or_kind).to(device).eval() |
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self.processor = HFCLIPImageProcessor.from_pretrained(repo_or_kind) |
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self.kind = "hf_clip" |
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self.preprocess = None |
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except: |
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raise ValueError(f"Failed to load model {repo_or_kind}: {e}") |
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if self.kind == "open_clip": |
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with torch.no_grad(): |
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img = Image.new('RGB', (224, 224), color=0) |
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x = self.preprocess(img).unsqueeze(0).to(device) |
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feat = self.model.encode_image(x) |
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self.embed_dim = int(feat.shape[-1]) |
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else: |
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self.embed_dim = int(self.model.config.projection_dim) |
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@torch.inference_mode() |
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def encode_images(self, paths: List[str]) -> torch.Tensor: |
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ims = [] |
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if self.kind == "open_clip": |
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for p in paths: |
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try: |
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im = Image.open(p).convert("RGB") |
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except: |
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im = Image.new("RGB", (224, 224), color=0) |
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ims.append(self.preprocess(im)) |
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x = torch.stack(ims).to(self.device) |
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f = self.model.encode_image(x) |
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else: |
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for p in paths: |
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try: |
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im = Image.open(p).convert("RGB") |
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except: |
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im = Image.new("RGB", (224, 224), color=0) |
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ims.append(im) |
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proc = self.processor(images=ims, return_tensors='pt') |
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x = proc['pixel_values'].to(self.device) |
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f = self.model.get_image_features(pixel_values=x) |
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return F.normalize(f, dim=-1) |
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class Captioner(nn.Module): |
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def __init__(self, gpt2_name: str, clip_repo: str, prefix_tokens: int, prompt: str, device: str): |
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super().__init__() |
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self.device = device |
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self.prompt = prompt |
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self.tok = AutoTokenizer.from_pretrained(gpt2_name) |
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if self.tok.pad_token is None: |
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self.tok.pad_token = self.tok.eos_token |
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self.gpt2 = AutoModelForCausalLM.from_pretrained(gpt2_name).to(device).eval() |
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self.clip = CLIPBackend(clip_repo, device) |
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self.prefix = PrefixProjector(self.clip.embed_dim, int(self.gpt2.config.n_embd), prefix_tokens).to(device).eval() |
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@torch.inference_mode() |
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def generate(self, img_paths: List[str], prompt: Optional[str] = None) -> List[str]: |
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pr = prompt or self.prompt or "" |
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f = self.clip.encode_images(img_paths) |
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pref = self.prefix(f) |
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ids = self.tok([pr]*pref.size(0), return_tensors='pt', padding=True, truncation=True).to(self.device) |
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emb_prompt = self.gpt2.transformer.wte(ids['input_ids']) |
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inputs_embeds = torch.cat([pref, emb_prompt], dim=1) |
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attn = torch.ones(inputs_embeds.size()[:-1], dtype=torch.long, device=self.device) |
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gen = self.gpt2.generate( |
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inputs_embeds=inputs_embeds, attention_mask=attn, |
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max_new_tokens=60, min_new_tokens=24, num_beams=4, |
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no_repeat_ngram_size=4, repetition_penalty=1.15, length_penalty=0.6, |
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pad_token_id=self.tok.eos_token_id, eos_token_id=self.tok.eos_token_id, early_stopping=True |
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) |
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outs = self.tok.batch_decode(gen, skip_special_tokens=True) |
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res = [] |
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for s in outs: |
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cut = s.find(pr) |
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if cut >= 0: s = s[cut+len(pr):] |
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res.append(s.strip()) |
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return res |
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def load_model(repo_dir: str | os.PathLike) -> Captioner: |
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repo_dir = Path(repo_dir) |
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cfgs = sorted(repo_dir.glob("final_captioner_*.json")) |
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if not cfgs: |
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raise FileNotFoundError("final_captioner_*.json not found in repo snapshot") |
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data = json.loads(cfgs[-1].read_text(encoding='utf-8')) |
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gpt2 = data.get("gpt2_name", "gpt2-medium") |
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clip_repo = data.get("clip_weight_path", data.get("clip_repo", data.get("clip_backend_kind", ""))) |
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if not clip_repo or clip_repo in ["open_clip", "hf_clip"]: |
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ckpts = sorted(repo_dir.glob("final_captioner_*.pt")) |
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if ckpts: |
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ckpt_name = str(ckpts[-1]) |
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if "TimmModel" in ckpt_name: |
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clip_repo = "microsoft/BiomedCLIP-PubMedBERT_256-vit_base_patch16_224" |
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elif "VisionTransformer" in ckpt_name: |
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clip_repo = "redlessone/DermLIP_ViT-B-16" |
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elif "CLIPModel" in ckpt_name: |
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clip_repo = "flaviagiammarino/pubmed-clip-vit-base-patch32" |
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elif "biomedclip" in ckpt_name.lower(): |
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clip_repo = "microsoft/BiomedCLIP-PubMedBERT_256-vit_base_patch16_224" |
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prefix_tokens = int(data.get("prefix_tokens", 32)) |
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prompt = data.get("prompt", "Describe the skin lesion.") |
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device = "cuda" if torch.cuda.is_available() else "cpu" |
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model = Captioner(gpt2, clip_repo, prefix_tokens, prompt, device).to(device).eval() |
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ckpts = sorted(repo_dir.glob("final_captioner_*.pt")) |
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if not ckpts: |
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raise FileNotFoundError("final_captioner_*.pt not found in repo snapshot") |
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state = torch.load(ckpts[-1], map_location="cpu") |
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sd = state.get("model", state) |
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model.load_state_dict(sd, strict=False) |
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return model |
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def generate(model: Captioner, img_paths: List[str], prompt: Optional[str] = None) -> List[str]: |
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return model.generate(img_paths, prompt=prompt) |
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