2026-05-04-05-20-16 优化DICOM切片下载和3D预览

WebSite/server.ts

@@ -87,7 +87,11 @@ function listFiles(dir: string, extension: string) {
     .readdirSync(dir, { withFileTypes: true })
     .filter((entry) => entry.isFile() && entry.name.toLowerCase().endsWith(extension))
     .map((entry) => entry.name)
-    .sort((a, b) => a.localeCompare(b, 'zh-Hans-CN'));
+    .sort(naturalFileCompare);
+}
+
+function naturalFileCompare(a: string, b: string) {
+  return a.localeCompare(b, 'zh-Hans-CN', { numeric: true, sensitivity: 'base' });
 }
 
 function publicUser(user: UserRecord) {
@@ -279,7 +283,7 @@ function getProjectDicomFiles(project: ProjectRecord) {
   if (project.id !== 'head-ct-demo') {
     return [];
   }
-  return listFiles(dicomDir, '.dcm').sort((a, b) => Number.parseInt(a) - Number.parseInt(b));
+  return listFiles(dicomDir, '.dcm');
 }
 
 function readAsciiValue(buffer: Buffer, start: number, length: number) {
@@ -375,10 +379,12 @@ function parseDicomPreview(filePath: string, mode: DicomDisplayMode = 'default')
     pixels[i] = normalized;
   }
 
+  const enhancedPixels = enhanceDicomEdges(pixels, columns, rows);
+
   return {
     width: columns,
     height: rows,
-    pixels: pixels.toString('base64'),
+    pixels: enhancedPixels.toString('base64'),
     windowCenter,
     windowWidth,
     mode,
@@ -440,10 +446,13 @@ function createReformattedPreview(files: string[], plane: Exclude<DicomPlane, 'a
     }
   });
 
+  const cropped = cropDicomContent(pixels, outputWidth, outputHeight);
+  const enhancedPixels = enhanceDicomEdges(cropped.pixels, cropped.width, cropped.height);
+
   return {
-    width: outputWidth,
-    height: outputHeight,
-    pixels: pixels.toString('base64'),
+    width: cropped.width,
+    height: cropped.height,
+    pixels: enhancedPixels.toString('base64'),
     windowCenter: volume.windowCenter,
     windowWidth: volume.windowWidth,
     slice: clampedSlice,
@@ -453,6 +462,71 @@ function createReformattedPreview(files: string[], plane: Exclude<DicomPlane, 'a
   };
 }
 
+function enhanceDicomEdges(pixels: Buffer, width: number, height: number) {
+  if (width < 3 || height < 3) {
+    return pixels;
+  }
+
+  const output = Buffer.from(pixels);
+  for (let y = 1; y < height - 1; y += 1) {
+    for (let x = 1; x < width - 1; x += 1) {
+      const index = y * width + x;
+      const center = pixels[index];
+      const neighborAverage = (
+        pixels[index - 1] +
+        pixels[index + 1] +
+        pixels[index - width] +
+        pixels[index + width]
+      ) / 4;
+      const sharpened = Math.round(center * 1.08 + (center - neighborAverage) * 0.55);
+      output[index] = Math.max(0, Math.min(255, sharpened));
+    }
+  }
+  return output;
+}
+
+function cropDicomContent(pixels: Buffer, width: number, height: number) {
+  const threshold = 12;
+  const columnHits = Array.from({ length: width }, () => 0);
+  const rowHits = Array.from({ length: height }, () => 0);
+
+  for (let y = 0; y < height; y += 1) {
+    for (let x = 0; x < width; x += 1) {
+      if (pixels[y * width + x] > threshold) {
+        columnHits[x] += 1;
+        rowHits[y] += 1;
+      }
+    }
+  }
+
+  const minColumnHits = Math.max(4, Math.floor(height * 0.012));
+  const minRowHits = Math.max(4, Math.floor(width * 0.012));
+  let minX = columnHits.findIndex((hits) => hits >= minColumnHits);
+  let maxX = width - 1 - [...columnHits].reverse().findIndex((hits) => hits >= minColumnHits);
+  let minY = rowHits.findIndex((hits) => hits >= minRowHits);
+  let maxY = height - 1 - [...rowHits].reverse().findIndex((hits) => hits >= minRowHits);
+
+  if (maxX < minX || maxY < minY) {
+    return { pixels, width, height };
+  }
+
+  const padding = 18;
+  minX = Math.max(0, minX - padding);
+  minY = Math.max(0, minY - padding);
+  maxX = Math.min(width - 1, maxX + padding);
+  maxY = Math.min(height - 1, maxY + padding);
+
+  const croppedWidth = maxX - minX + 1;
+  const croppedHeight = maxY - minY + 1;
+  const croppedPixels = Buffer.alloc(croppedWidth * croppedHeight);
+  for (let row = 0; row < croppedHeight; row += 1) {
+    const sourceStart = (minY + row) * width + minX;
+    pixels.copy(croppedPixels, row * croppedWidth, sourceStart, sourceStart + croppedWidth);
+  }
+
+  return { pixels: croppedPixels, width: croppedWidth, height: croppedHeight };
+}
+
 function createStlPreview(filePath: string, fileName: string, limit: number) {
   const cacheKey = `${fileName}:${limit}`;
   const cached = modelPreviewCache.get(cacheKey);
@@ -503,6 +577,52 @@ function createStlPreview(filePath: string, fileName: string, limit: number) {
   return payload;
 }
 
+function writeOctal(buffer: Buffer, value: number, offset: number, length: number) {
+  const text = value.toString(8).padStart(length - 1, '0').slice(-(length - 1));
+  buffer.write(`${text}\0`, offset, length, 'ascii');
+}
+
+function createTarEntryHeader(name: string, size: number, mtime: number) {
+  const header = Buffer.alloc(512);
+  const safeName = name.slice(0, 100);
+  header.write(safeName, 0, 100, 'utf8');
+  writeOctal(header, 0o644, 100, 8);
+  writeOctal(header, 0, 108, 8);
+  writeOctal(header, 0, 116, 8);
+  writeOctal(header, size, 124, 12);
+  writeOctal(header, Math.floor(mtime), 136, 12);
+  header.fill(' ', 148, 156);
+  header.write('0', 156, 1, 'ascii');
+  header.write('ustar', 257, 6, 'ascii');
+  header.write('00', 263, 2, 'ascii');
+
+  let checksum = 0;
+  for (const byte of header) {
+    checksum += byte;
+  }
+  writeOctal(header, checksum, 148, 8);
+  return header;
+}
+
+function createDicomTarGz(files: string[]) {
+  const chunks: Buffer[] = [];
+
+  files.forEach((fileName) => {
+    const filePath = path.join(dicomDir, fileName);
+    const stat = fs.statSync(filePath);
+    const data = fs.readFileSync(filePath);
+    chunks.push(createTarEntryHeader(`Head_CT_DICOM/${fileName}`, data.length, stat.mtimeMs / 1000));
+    chunks.push(data);
+    const remainder = data.length % 512;
+    if (remainder > 0) {
+      chunks.push(Buffer.alloc(512 - remainder));
+    }
+  });
+
+  chunks.push(Buffer.alloc(1024));
+  return zlib.gzipSync(Buffer.concat(chunks));
+}
+
 async function startServer() {
   const app = express();
   const host = process.argv.includes('--host') ? process.argv[process.argv.indexOf('--host') + 1] : '0.0.0.0';
@@ -655,6 +775,30 @@ async function startServer() {
     }
   });
 
+  app.get('/api/projects/:projectId/dicom-archive', (req, res) => {
+    const project = findProject(readState(), req.params.projectId);
+    if (!project) {
+      res.status(404).json({ message: '项目不存在' });
+      return;
+    }
+
+    const files = getProjectDicomFiles(project);
+    if (!files.length) {
+      res.status(404).json({ message: '当前项目没有可下载的 DICOM 文件' });
+      return;
+    }
+
+    try {
+      const archive = createDicomTarGz(files);
+      const filename = `${project.id}-${project.dicomPath || 'DICOM'}-${files.length}-files.tar.gz`;
+      res.setHeader('Content-Type', 'application/gzip');
+      res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
+      res.send(archive);
+    } catch (error) {
+      res.status(500).json({ message: error instanceof Error ? error.message : 'DICOM 压缩包生成失败' });
+    }
+  });
+
   app.get('/api/projects/:projectId/models/:fileName', (req, res) => {
     const project = findProject(readState(), req.params.projectId);
     const fileName = path.basename(req.params.fileName);