Basic functioning

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ldy 2025-06-13 15:00:33 +08:00
parent e704bde69b
commit 44c2e74a7a
6 changed files with 160 additions and 199 deletions

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import os
import argparse
import numpy as np
from tqdm import tqdm
from pycocotools.coco import COCO
from PIL import Image
import torch
from embedder import ImageEmbedder, DEVICE
from text_embedder import TextEmbedder
def parse_args():
p = argparse.ArgumentParser(description="COCO retrieval benchmark")
p.add_argument("--coco-annotation-json", required=True,
help="path to captions_val2017.json")
p.add_argument("--coco-image-dir", required=True,
help="path to val2017/ folder")
p.add_argument("--llava-ckpt", required=True,
help="path to pytorch_model-00003-of-00003.bin")
p.add_argument("--proj-model", default="openai/clip-vit-large-patch14-336")
p.add_argument("--proj-dim", type=int, default=5120)
p.add_argument("--text-model", required=True)
p.add_argument("--text-tokenizer", required=True)
p.add_argument("--batch-size", type=int, default=64)
return p.parse_args()
def load_coco(ann_file):
coco = COCO(ann_file)
img_ids = coco.getImgIds()
img2caps = {iid: [ann["caption"] for ann in coco.loadAnns(coco.getAnnIds(imgIds=iid))]
for iid in img_ids}
return coco, img_ids, img2caps
def compute_image_embeddings(embedder, coco, img_ids, img_dir, bs):
all_embs = []
for i in tqdm(range(0, len(img_ids), bs), desc="Images"):
batch = img_ids[i:i + bs]
imgs = []
for iid in batch:
fn = coco.loadImgs(iid)[0]["file_name"]
imgs.append(Image.open(os.path.join(img_dir, fn)).convert("RGB"))
with torch.no_grad():
embs = torch.stack([embedder.image_to_embedding(im) for im in imgs])
all_embs.append(embs.cpu().numpy())
return np.vstack(all_embs)
def compute_text_embeddings(embedder, captions, bs):
all_embs = []
for i in tqdm(range(0, len(captions), bs), desc="Texts"):
batch = captions[i:i + bs]
with torch.no_grad():
embs = embedder.text_to_embedding(batch)
all_embs.append(embs.cpu().numpy())
return np.vstack(all_embs)
def compute_metrics(ranks, gt, K=(1, 5, 10)):
R, meds = {k: 0 for k in K}, []
for idx, rank_list in enumerate(ranks):
targets = gt[idx]
best = min(int(np.where(rank_list == t)[0][0]) for t in targets)
meds.append(best + 1)
for k in K:
if best < k:
R[k] += 1
n = len(ranks)
recall = {k: R[k] / n for k in K}
return recall, np.median(meds)
def evaluate(img_embs, txt_embs, img2caps, img_ids):
sims = img_embs @ txt_embs.T
# Image→Text
img2cap = {}
offset = 0
for i, iid in enumerate(img_ids):
cnt = len(img2caps[iid])
img2cap[i] = list(range(offset, offset + cnt))
offset += cnt
ranks_i2t = np.argsort(-sims, axis=1)
R_i2t, med_i2t = compute_metrics(ranks_i2t, img2cap)
print("Image→Text R@1,5,10:", [f"{R_i2t[k] * 100:.2f}%" for k in (1, 5, 10)])
print("Image→Text Median Rank:", med_i2t)
# Text→Image
cap2img, offset = {}, 0
for i, iid in enumerate(img_ids):
for _ in img2caps[iid]:
cap2img[offset] = i
offset += 1
ranks_t2i = np.argsort(-sims.T, axis=1)
gt = {idx: [cap2img[idx]] for idx in range(len(ranks_t2i))}
R_t2i, med_t2i = compute_metrics(ranks_t2i, gt)
print("Text→Image R@1,5,10:", [f"{R_t2i[k] * 100:.2f}%" for k in (1, 5, 10)])
print("Text→Image Median Rank:", med_t2i)
def main():
args = parse_args()
# 1) Load COCO
coco, img_ids, img2caps = load_coco(args.coco_annotation_json)
captions = [c for iid in img_ids for c in img2caps[iid]]
# 2) Build embedders
img_embedder = ImageEmbedder(
vision_model_name=args.proj_model,
proj_out_dim=args.proj_dim,
llava_ckpt_path=args.llava_ckpt
)
txt_embedder = TextEmbedder(
model_name=args.text_model,
tokenizer_name=args.text_tokenizer
)
# 3) Compute embeddings
img_vectors = compute_image_embeddings(
img_embedder, coco, img_ids, args.coco_image_dir, args.batch_size
)
txt_vectors = compute_text_embeddings(
txt_embedder, captions, args.batch_size
)
# 4) Evaluate Retrieval
evaluate(img_vectors, txt_vectors, img2caps, img_ids)
if __name__ == "__main__":
main()

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import torch import torch
from transformers import CLIPImageProcessor, CLIPVisionModel from transformers import CLIPImageProcessor, CLIPVisionModel
from PIL import Image from PIL import Image
# Force use of GPU 0 (or change “0” to whichever GPU index you want)
import os
print(torch.version.cuda)
os.environ["CUDA_VISIBLE_DEVICES"] = "0"
# Now select device # Use CUDA
if not torch.cuda.is_available(): DEVICE = torch.device("cuda" if torch.cuda.is_available() else "cpu")
raise RuntimeError("CUDA is not available—cannot run on GPU")
DEVICE = torch.device("cuda") # no fallback to CPU
print(f"→ Running exclusively on {torch.cuda.get_device_name(0)}")
class ImageEmbedder: class ImageEmbedder:
@ -27,7 +19,7 @@ class ImageEmbedder:
.to(DEVICE) .to(DEVICE)
.eval() .eval()
) )
# Freeze it # Freeze version
for p in self.vision_model.parameters(): for p in self.vision_model.parameters():
p.requires_grad = False p.requires_grad = False
@ -36,7 +28,7 @@ class ImageEmbedder:
self.projection = torch.nn.Linear(vision_hidden_dim, proj_out_dim).to(DEVICE) self.projection = torch.nn.Linear(vision_hidden_dim, proj_out_dim).to(DEVICE)
self.projection.eval() self.projection.eval()
# If provided, load LLaVAs projection weights from the full bin checkpoint # Load LLaVAs projection weights from the full bin checkpoint
if llava_ckpt_path is not None: if llava_ckpt_path is not None:
ckpt = torch.load(llava_ckpt_path, map_location=DEVICE) ckpt = torch.load(llava_ckpt_path, map_location=DEVICE)
# extract only the projector weights + bias # extract only the projector weights + bias
@ -58,5 +50,6 @@ class ImageEmbedder:
out = self.vision_model(pixel_values=pixel_values) out = self.vision_model(pixel_values=pixel_values)
feat = out.pooler_output # (1,1024) feat = out.pooler_output # (1,1024)
emb = self.projection(feat) # (1,proj_out_dim) emb = self.projection(feat) # (1,proj_out_dim)
# Returns a 1D tensor of size [proj_out_dim] on DEVICE
# Returns a 1D tensor of size [proj_out_dim] on DEVICE.
return emb.squeeze(0) # → (proj_out_dim,) return emb.squeeze(0) # → (proj_out_dim,)

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find_similar_img.py Normal file
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import numpy as np
import pickle
from PIL import Image
from sklearn.metrics.pairwise import cosine_similarity
from embedder import ImageEmbedder
# ——— Load stored embeddings & mapping ———
vecs = np.load("processed_images/image_vectors.npy") # (N, D)
with open("processed_images/index_to_file.pkl", "rb") as f:
idx2file = pickle.load(f) # dict: idx → filepath
# ——— Specify query image ———
query_path = "datasets/coco/val2017/1140002154.jpg"
# ——— Embed the query image ———
embedder = ImageEmbedder(
vision_model_name="openai/clip-vit-large-patch14-336",
proj_out_dim=5120,
llava_ckpt_path="datasets/pytorch_model-00003-of-00003.bin"
)
img = Image.open(query_path).convert("RGB")
q_vec = embedder.image_to_embedding(img).cpu().numpy() # (D,)
# ——— Compute similarities & retrieve top-k ———
# (you can normalize if you built your DB with inner-product indexing)
# vecs_norm = vecs / np.linalg.norm(vecs, axis=1, keepdims=True)
# q_vec_norm = q_vec / np.linalg.norm(q_vec)
# sims = cosine_similarity(q_vec_norm.reshape(1, -1), vecs_norm).flatten()
sims = cosine_similarity(q_vec.reshape(1, -1), vecs).flatten()
top5 = sims.argsort()[-5:][::-1]
# ——— Print out the results ———
print(f"Query image: {query_path}\n")
for rank, idx in enumerate(top5, 1):
print(f"{rank:>2}. {idx2file[idx]} (score: {sims[idx]:.4f})")

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readme.md Normal file
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# Img2Vec
A rough implementation of generating image embeddings through methodologies introduced in LLaVA
### Structure
We derived the image embeddings by using a CLIP encoder and mapping it with the pretrained LLaVAs projection weight
### Prerequisites
1. install requirements.txt
2. Make sure you have downloaded `pytorch_model-00003-of-00003.bin`
### Usage
Replace **image-dir** and **llava-ckpt** to your **test image folder addr** and **pytorch_model-00003-of-00003.bin addr**
`python convert_images_to_vectors.py --image-dir ./datasets/coco/val2017 --output-dir imgVecs --vision-model openai/clip-vit-large-patch14-336 --proj-dim 5120 --llava-ckpt ./datasets/pytorch_model-00003-of-00003.bin --batch-size 64`

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starter.py Normal file
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import os
import argparse
import pickle
import numpy as np
from PIL import Image
import torch
from embedder import ImageEmbedder, DEVICE
def parse_args():
p = argparse.ArgumentParser(
description="Batch-convert a folder of images into embedding vectors"
)
p.add_argument(
"--image-dir", required=True,
help="Path to a folder containing images (jpg/png/bmp/gif)"
)
p.add_argument(
"--output-dir", default="processed_images",
help="Where to save image_vectors.npy and index_to_file.pkl"
)
p.add_argument(
"--vision-model", default="openai/clip-vit-large-patch14-336",
help="Hugging Face name of the CLIP vision encoder"
)
p.add_argument(
"--proj-dim", type=int, default=5120,
help="Dimensionality of the projection output"
)
p.add_argument(
"--llava-ckpt", default=None,
help="(Optional) full LLaVA checkpoint .bin to load projector weights from"
)
p.add_argument(
"--batch-size", type=int, default=64,
help="How many images to encode per GPU/CPU batch"
)
return p.parse_args()
def find_images(folder):
exts = (".jpg", ".jpeg", ".png", ".bmp", ".gif")
return sorted([
os.path.join(folder, fname)
for fname in os.listdir(folder)
if fname.lower().endswith(exts)
])
def main():
args = parse_args()
os.makedirs(args.output_dir, exist_ok=True)
# Discover images
image_paths = find_images(args.image_dir)
if not image_paths:
raise RuntimeError(f"No images found in {args.image_dir}")
print(f"Found {len(image_paths)} images in {args.image_dir}")
# Build embedder
embedder = ImageEmbedder(
vision_model_name=args.vision_model,
proj_out_dim=args.proj_dim,
llava_ckpt_path=args.llava_ckpt
)
print(f"Using device: {DEVICE}")
# Process in batches
all_embs = []
index_to_file = {}
for batch_start in range(0, len(image_paths), args.batch_size):
batch_paths = image_paths[batch_start:batch_start + args.batch_size]
# load images
imgs = [Image.open(p).convert("RGB") for p in batch_paths]
# embed
with torch.no_grad():
embs = embedder.image_to_embedding(imgs) # (B, D)
embs_np = embs.cpu().numpy()
all_embs.append(embs_np)
# record mapping
for i, p in enumerate(batch_paths):
index_to_file[batch_start + i] = p
print(f" • Processed {batch_start + len(batch_paths)}/{len(image_paths)} images")
# Stack and save
vectors = np.vstack(all_embs) # shape (N, D)
vec_file = os.path.join(args.output_dir, "image_vectors.npy")
map_file = os.path.join(args.output_dir, "index_to_file.pkl")
np.save(vec_file, vectors)
with open(map_file, "wb") as f:
pickle.dump(index_to_file, f)
print(f"\nSaved {vectors.shape[0]}×{vectors.shape[1]} vectors to\n {vec_file}")
print(f"Saved index→file mapping to\n {map_file}")
if __name__ == "__main__":
main()

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import torch
from transformers import AutoTokenizer, AutoModel
from typing import List
# Use the same DEVICE as embedder
DEVICE = torch.device("cuda" if torch.cuda.is_available() else "cpu")
class TextEmbedder:
"""
Encodes text into the same embedding space (assumes your LLM was aligned
with LLaVAs projector during fine-tuning).
"""
def __init__(self,
model_name: str,
tokenizer_name: str = None):
tokenizer_name = tokenizer_name or model_name
self.tokenizer = AutoTokenizer.from_pretrained(tokenizer_name)
self.text_model = (
AutoModel
.from_pretrained(model_name)
.to(DEVICE)
.eval()
)
for p in self.text_model.parameters():
p.requires_grad = False
def text_to_embedding(self, texts: List[str]) -> torch.Tensor:
"""
Returns a tensor of shape (batch_size, hidden_dim) on DEVICE.
Uses pooler_output if available; otherwise mean-pools tokens.
"""
inputs = self.tokenizer(
texts,
padding=True,
truncation=True,
return_tensors="pt"
)
# move all inputs to GPU if available
inputs = {k: v.to(DEVICE) for k, v in inputs.items()}
with torch.no_grad():
outputs = self.text_model(**inputs)
if hasattr(outputs, "pooler_output") and outputs.pooler_output is not None:
emb = outputs.pooler_output # (batch, hidden_dim)
else:
emb = outputs.last_hidden_state.mean(dim=1)
return emb