[Frontend] Support multimodal inputs for late-interaction scoring (ColQwen3) + NewModel: nvidia/nemotron-colembed (#34574)

Signed-off-by: craftsangjae <craftsangjae@gmail.com>

examples/pooling/score/colqwen3_rerank_online.py

@@ -1,7 +1,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+# ruff: noqa: E501
 """
-Example of using ColQwen3 late interaction model for reranking.
+Example of using ColQwen3 late interaction model for reranking and scoring.
 
 ColQwen3 is a multi-modal ColBERT-style model based on Qwen3-VL.
 It produces per-token embeddings and uses MaxSim scoring for retrieval
@@ -14,13 +15,65 @@ Then run this script:
     python colqwen3_rerank_online.py
 """
 
+import base64
+from io import BytesIO
+
 import requests
+from PIL import Image
 
 MODEL = "TomoroAI/tomoro-colqwen3-embed-4b"
 BASE_URL = "http://127.0.0.1:8000"
 
 headers = {"accept": "application/json", "Content-Type": "application/json"}
 
+# ── Image helpers ──────────────────────────────────────────
+
+
+def load_image(url: str) -> Image.Image:
+    """Download an image from URL (handles Wikimedia 403)."""
+    for hdrs in (
+        {},
+        {"User-Agent": "Mozilla/5.0 (compatible; ColQwen3-demo/1.0)"},
+    ):
+        resp = requests.get(url, headers=hdrs, timeout=15)
+        if resp.status_code == 403:
+            continue
+        resp.raise_for_status()
+        return Image.open(BytesIO(resp.content)).convert("RGB")
+    raise RuntimeError(f"Could not fetch image from {url}")
+
+
+def encode_image_base64(image: Image.Image) -> str:
+    """Encode a PIL image to a base64 data URI."""
+    buf = BytesIO()
+    image.save(buf, format="PNG")
+    return "data:image/png;base64," + base64.b64encode(buf.getvalue()).decode()
+
+
+def make_image_content(image_url: str, text: str = "Describe the image.") -> dict:
+    """Build a ScoreMultiModalParam dict from an image URL."""
+    image = load_image(image_url)
+    return {
+        "content": [
+            {
+                "type": "image_url",
+                "image_url": {"url": encode_image_base64(image)},
+            },
+            {"type": "text", "text": text},
+        ]
+    }
+
+
+# ── Sample image URLs ─────────────────────────────────────
+
+IMAGE_URLS = {
+    "beijing": "https://upload.wikimedia.org/wikipedia/commons/6/61/Beijing_skyline_at_night.JPG",
+    "london": "https://upload.wikimedia.org/wikipedia/commons/4/49/London_skyline.jpg",
+    "singapore": "https://upload.wikimedia.org/wikipedia/commons/2/27/Singapore_skyline_2022.jpg",
+}
+
+# ── Text-only examples ────────────────────────────────────
+
 
 def rerank_text():
     """Text-only reranking via /rerank endpoint."""
@@ -120,11 +173,86 @@ def score_text_top_n():
         print(f"  {response.text[:300]}")
 
 
+# ── Multi-modal examples (text query × image documents) ──
+
+
+def score_text_vs_images():
+    """Score a text query against image documents via /score."""
+    print()
+    print("=" * 60)
+    print("4. Multi-modal scoring: text query vs image docs (/score)")
+    print("=" * 60)
+
+    query = "Retrieve the city of Beijing"
+    labels = list(IMAGE_URLS.keys())
+    print(f"\n  Loading {len(labels)} images...")
+    image_contents = [make_image_content(IMAGE_URLS[name]) for name in labels]
+
+    data = {
+        "model": MODEL,
+        "data_1": query,
+        "data_2": image_contents,
+    }
+
+    response = requests.post(f"{BASE_URL}/score", headers=headers, json=data)
+
+    if response.status_code == 200:
+        result = response.json()
+        print(f'\n  Query: "{query}"\n')
+        for item in result["data"]:
+            idx = item["index"]
+            print(f"    Doc {idx} [{labels[idx]}] score={item['score']:.4f}")
+    else:
+        print(f"  Request failed: {response.status_code}")
+        print(f"  {response.text[:300]}")
+
+
+def rerank_text_vs_images():
+    """Rerank image documents by a text query via /rerank."""
+    print()
+    print("=" * 60)
+    print("5. Multi-modal reranking: text query vs image docs (/rerank)")
+    print("=" * 60)
+
+    query = "Retrieve the city of London"
+    labels = list(IMAGE_URLS.keys())
+    print(f"\n  Loading {len(labels)} images...")
+    image_contents = [make_image_content(IMAGE_URLS[name]) for name in labels]
+
+    data = {
+        "model": MODEL,
+        "query": query,
+        "documents": image_contents,
+        "top_n": 2,
+    }
+
+    response = requests.post(f"{BASE_URL}/rerank", headers=headers, json=data)
+
+    if response.status_code == 200:
+        result = response.json()
+        print(f'\n  Query: "{query}"')
+        print(f"  Top {data['top_n']} results:\n")
+        for item in result["results"]:
+            idx = item["index"]
+            print(f"    [{item['relevance_score']:.4f}] {labels[idx]}")
+    else:
+        print(f"  Request failed: {response.status_code}")
+        print(f"  {response.text[:300]}")
+
+
+# ── Main ──────────────────────────────────────────────────
+
+
 def main():
+    # Text-only
     rerank_text()
     score_text()
     score_text_top_n()
 
+    # Multi-modal (text query × image documents)
+    score_text_vs_images()
+    rerank_text_vs_images()
+
 
 if __name__ == "__main__":
     main()