保留 16 位 PNG 原图和色彩信息

lib/canvas/photoshop-safe-download.ts

@@ -217,7 +217,9 @@ export async function convertImageToPhotoshopPng(bytes: Buffer): Promise<Buffer>
     throw new Error("无法解析图片尺寸");
   }
   // RGB/RGBA, 8-bit, single-frame PNG is already compatible; preserve its exact bytes.
-  if (metadata.format === "png" && metadata.space === "srgb" && metadata.depth === "uchar"
+  const rgb = (metadata.space === "srgb" && metadata.depth === "uchar")
+    || (metadata.space === "rgb16" && metadata.depth === "ushort");
+  if (metadata.format === "png" && rgb
       && !metadata.isPalette && (metadata.pages || 1) === 1 && (!metadata.orientation || metadata.orientation === 1)) return bytes;
   return image.rotate().toColorspace("srgb").png({ compressionLevel: 3, adaptiveFiltering: true }).toBuffer();
 }

lib/storage/qiniu-image-archive.ts

@@ -29,7 +29,7 @@ function isDownloadReadyPng(prefix: Buffer) {
   if (prefix.length < 41 || !prefix.subarray(0, 8).equals(PNG_SIGNATURE)
     || prefix.readUInt32BE(8) !== 13 || prefix.toString("ascii", 12, 16) !== "IHDR"
     || !prefix.readUInt32BE(16) || !prefix.readUInt32BE(20)
-    || prefix[24] !== 8 || (prefix[25] !== 2 && prefix[25] !== 6)) return false;
+    || (prefix[24] !== 8 && prefix[24] !== 16) || (prefix[25] !== 2 && prefix[25] !== 6)) return false;
 
   // Animation and EXIF orientation need the existing full-image preparation.
   // An embedded color profile is fine: the browser gets the exact stored bytes.

tests/routes/canvas-download-recovery.test.ts

@@ -124,6 +124,7 @@ test("requested downloads are prioritized with two workers before scanning backg
     },
     "./image-byte-cache": { fetchImageBytes: async () => { active++; maximum = Math.max(maximum, active); await new Promise<void>(resolve => releases.push(resolve)); active--; return { buffer: bytes, contentType: "image/png" }; }, cacheImageBytes: async () => {} },
     "@/lib/canvas/photoshop-safe-download": { normalizeCanvasDownloadAsset: async () => ({ ok: true, bytes, contentType: "image/png" }) },
+    "./qiniu-image-archive": { getReadyQiniuImageDownload: async () => undefined },
     "./service": { uploadFile() { throw new Error("Compatible PNG must retain its object"); } },
   })("lib/storage/image-download-preparation.ts");
   worker.scheduleImageDownloadPreparation("one"); worker.scheduleImageDownloadPreparation("two"); worker.scheduleImageDownloadPreparation("three");

tests/routes/canvas-download-speed.test.ts

@@ -106,6 +106,8 @@ test("compatible PNG remains byte-identical; JPEG becomes RGB PNG without resizi
   const module = serverLoader({})("lib/canvas/photoshop-safe-download.ts");
   const bytes = await sharp({ create: { width: 32, height: 48, channels: 4, background: "#12345680" } }).png().toBuffer();
   expect((await module.convertImageToPhotoshopPng(bytes)).equals(bytes)).toBe(true);
+  const rgb16 = await sharp(bytes).toColourspace("rgb16").png().toBuffer();
+  expect((await module.convertImageToPhotoshopPng(rgb16)).equals(rgb16)).toBe(true);
   const jpeg = await sharp(bytes).jpeg().toBuffer();
   const converted = await module.convertImageToPhotoshopPng(jpeg);
   const metadata = await sharp(converted).metadata();

tests/routes/image-archive-flow.test.ts

@@ -86,6 +86,7 @@ const loggerMock = { createLogger: () => ({ info() {}, warn() {}, error() {} })
 test("Qiniu archives 98K originals without relaying full image bytes through the app", async () => {
   const image = sharp({ create: { width: 4, height: 4, channels: 3, background: "blue" } });
   const rgb = await image.clone().withIccProfile("srgb").png().toBuffer();
+  const rgb16 = await image.clone().toColourspace("rgb16").png().toBuffer();
   const indexed = await image.clone().png({ palette: true }).toBuffer();
   const config = { provider: "qiniu-kodo", region: "cn-east-1", bucket: "archive",
     accessKeyId: "test-key", secretAccessKey: "test-secret", publicUrl: "https://bucket.example" };
@@ -122,11 +123,13 @@ test("Qiniu archives 98K originals without relaying full image bytes through the
   })("lib/storage/qiniu-image-archive.ts");
   const archived = await load.archiveImageThroughQiniu(source, id);
   expect(archived.downloadAsset).toMatchObject({ status: "ready", url: archiveUrl, bytes: rgb.length });
+  stored = rgb16;
+  expect((await load.archiveImageThroughQiniu(source, id)).downloadAsset).toMatchObject({ status: "ready", url: archiveUrl, bytes: rgb16.length });
   stored = indexed;
   expect((await load.archiveImageThroughQiniu(source, id)).downloadAsset).toBeUndefined();
   expect(await load.archiveImageThroughQiniu("https://another-provider.example/result.png", id)).toBeNull();
-  expect(cloudCalls).toHaveLength(2);
-  expect(reads).toHaveLength(2);
+  expect(cloudCalls).toHaveLength(3);
+  expect(reads).toHaveLength(3);
 });
 
 test("160 requests from the same user and model start without admission waiting", async () => {