add DICOM slice previews to image library

WebSite/src/App.tsx

@@ -70,6 +70,77 @@ const API_BASE = typeof window === 'undefined'
   ? 'http://127.0.0.1:8787'
   : `${window.location.protocol}//${window.location.hostname}:8787`;
 
+function LibraryDicomPreview({ item }: { item: LibraryItem }) {
+  const [sliceIndex, setSliceIndex] = useState(Math.max(0, Math.floor((item.fileCount || 1) / 2)));
+  const [previewImage, setPreviewImage] = useState('');
+  const [isLoading, setIsLoading] = useState(false);
+  const [error, setError] = useState('');
+  const count = Math.max(1, item.fileCount || 1);
+
+  useEffect(() => {
+    setSliceIndex(Math.max(0, Math.floor((item.fileCount || 1) / 2)));
+  }, [item.id, item.fileCount]);
+
+  useEffect(() => {
+    const controller = new AbortController();
+    setIsLoading(true);
+    setError('');
+    fetch(`${API_BASE}/api/library/preview?id=${encodeURIComponent(item.id)}&index=${sliceIndex}`, {
+      signal: controller.signal
+    })
+      .then(async response => {
+        const data = await response.json();
+        if (!response.ok) throw new Error(data.error || '预览生成失败');
+        setPreviewImage(data.image);
+      })
+      .catch(error => {
+        if ((error as Error).name !== 'AbortError') setError((error as Error).message);
+      })
+      .finally(() => {
+        if (!controller.signal.aborted) setIsLoading(false);
+      });
+    return () => controller.abort();
+  }, [item.id, sliceIndex]);
+
+  return (
+    <div className="h-52 bg-slate-950 relative flex items-center justify-center border-b border-slate-100 shadow-inner overflow-hidden">
+      <div className="absolute top-3 left-4 flex gap-1.5 z-10">
+        <div className="w-1.5 h-1.5 rounded-full bg-white/25"></div>
+        <div className="w-1.5 h-1.5 rounded-full bg-white/25"></div>
+      </div>
+      <div className="absolute top-3 right-4 z-10">
+        <span className={`text-[8px] font-black px-2 py-0.5 rounded border ${item.status === 'processed' ? 'bg-green-500/20 text-green-400 border-green-500/30' : 'bg-amber-500/20 text-amber-400 border-amber-500/30'}`}>
+          {item.status.toUpperCase()}
+        </span>
+      </div>
+
+      {previewImage && !error ? (
+        <img src={previewImage} className="w-full h-full object-contain" />
+      ) : (
+        <div className="text-center text-white/35">
+          <ImageIcon size={34} className="mx-auto mb-2" />
+          <p className="text-[10px] font-bold">{error || (isLoading ? '正在生成预览...' : '等待预览')}</p>
+        </div>
+      )}
+
+      <div className="absolute inset-x-0 bottom-0 p-3 bg-gradient-to-t from-black/85 via-black/45 to-transparent">
+        <div className="flex items-center justify-between text-[8px] font-mono text-white/65 mb-2 uppercase tracking-[0.18em]">
+          <span>Axial DICOM</span>
+          <span>{sliceIndex + 1} / {count}</span>
+        </div>
+        <input
+          type="range"
+          min="0"
+          max={count - 1}
+          value={Math.min(sliceIndex, count - 1)}
+          onChange={event => setSliceIndex(parseInt(event.target.value, 10))}
+          className="w-full h-1 accent-blue-500 cursor-pointer"
+        />
+      </div>
+    </div>
+  );
+}
+
 export default function App() {
   // --- Authentication State ---
   const [isLoggedIn, setIsLoggedIn] = useState(false);
@@ -798,28 +869,7 @@ export default function App() {
               <div className="grid grid-cols-4 gap-8">
                 {libraryData.map(item => (
                   <div key={item.id} className="bg-white rounded-[2.5rem] border border-slate-200 overflow-hidden flex flex-col group hover:border-blue-400 hover:shadow-2xl hover:shadow-blue-500/10 transition-all duration-300">
-                    {/* Simulated Preview Box */}
+                    <LibraryDicomPreview item={item} />
-                    <div className={`h-44 ${item.previewColor} relative flex items-center justify-center p-6 border-b border-slate-100 shadow-inner group-hover:scale-[1.02] transition-transform`}>
-                       <div className="absolute top-3 left-4 flex gap-1.5">
-                          <div className="w-1.5 h-1.5 rounded-full bg-white/20"></div>
-                          <div className="w-1.5 h-1.5 rounded-full bg-white/20"></div>
-                       </div>
-                       {/* Abstract DICOM Scan Visualization */}
-                       <div className="w-full h-full border border-white/5 rounded-xl flex items-center justify-center overflow-hidden">
-                          <div className="w-24 h-24 border-2 border-dashed border-white/10 rounded-full animate-spin-slow opacity-30"></div>
-                          <div className="absolute w-20 h-28 border-2 border-white/20 rounded-[40%] rotate-45 blur-[1px]"></div>
-                          <div className="absolute w-28 h-20 border-2 border-white/20 rounded-[40%] -rotate-45 blur-[1px]"></div>
-                       </div>
-                       <div className="absolute inset-0 bg-gradient-to-t from-black/20 to-transparent"></div>
-                       <div className="absolute bottom-3 left-4 text-[7px] font-mono text-white/40 uppercase tracking-[0.2em] leading-none">
-                         Axial View :: ID_{item.id.toUpperCase()}
-                       </div>
-                       <div className="absolute top-3 right-4">
-                         <span className={`text-[8px] font-black px-2 py-0.5 rounded border ${item.status === 'processed' ? 'bg-green-500/20 text-green-400 border-green-500/30' : 'bg-amber-500/20 text-amber-400 border-amber-500/30'}`}>
-                           {item.status.toUpperCase()}
-                         </span>
-                       </div>
-                    </div>
                     
                     <div className="p-6 flex flex-col gap-4">
                       <div className="flex justify-between items-start">

web_backend.py

@@ -16,10 +16,14 @@ from urllib.parse import parse_qs, unquote, urlparse
 
 os.environ.setdefault("MPLCONFIGDIR", "/tmp/head_ct_morph_matplotlib")
 
+import pydicom
+from PIL import Image
+
 from generate_head_extension_video import generate_video
 from head_extension_app import (
     APP_DIR,
     crop_head_neck,
+    ct_window,
     fit_image,
     load_dicom_volume,
     preview_deform_2d,
@@ -109,6 +113,54 @@ def list_library():
     return live_items
 
 
+def sort_key_for_dicom(path):
+    path = Path(path)
+    try:
+        ds = pydicom.dcmread(str(path), stop_before_pixels=True, force=True)
+        return (0, int(getattr(ds, "InstanceNumber", 0)), path.name)
+    except Exception:
+        stem = path.stem
+        return (1, int(stem) if stem.isdigit() else 0, path.name)
+
+
+def sorted_dicom_files(dicom_dir):
+    return sorted(Path(dicom_dir).glob("*.dcm"), key=sort_key_for_dicom)
+
+
+def find_library_item(item_id):
+    return next((item for item in list_library() if item["id"] == item_id), None)
+
+
+def make_library_slice_preview(item_id, index):
+    item = find_library_item(item_id)
+    if not item:
+        raise RuntimeError("影像库中没有找到该数据。")
+
+    dicom_files = sorted_dicom_files(item["dicomPath"])
+    if not dicom_files:
+        raise RuntimeError("该影像数据没有可预览的 .dcm 文件。")
+
+    count = len(dicom_files)
+    index = max(0, min(int(index), count - 1))
+    ds = pydicom.dcmread(str(dicom_files[index]), force=True)
+    image = ds.pixel_array.astype("float32")
+    image = image * float(getattr(ds, "RescaleSlope", 1))
+    image = image + float(getattr(ds, "RescaleIntercept", 0))
+
+    preview = Image.fromarray(ct_window(image)).convert("RGB")
+    preview = fit_image(preview, 720, 520)
+    canvas = BytesIO()
+    preview.save(canvas, format="PNG")
+    encoded = base64.b64encode(canvas.getvalue()).decode("ascii")
+    return {
+        "image": f"data:image/png;base64,{encoded}",
+        "index": index,
+        "count": count,
+        "file": dicom_files[index].name,
+        "patientId": item["patientId"],
+    }
+
+
 def parse_multipart(headers, body):
     content_type = headers.get("content-type", "")
     message = BytesParser(policy=default).parsebytes(
@@ -333,6 +385,13 @@ class Handler(BaseHTTPRequestHandler):
             self.send_json({"items": list_library()})
             return
 
+        if parsed.path == "/api/library/preview":
+            params = parse_qs(parsed.query)
+            item_id = params.get("id", [""])[0]
+            index = params.get("index", ["0"])[0]
+            self.send_json(make_library_slice_preview(item_id, index))
+            return
+
         if parsed.path == "/api/job":
             params = parse_qs(parsed.query)
             job_id = params.get("id", [""])[0]