JPEG Ultra HDR / JPEG_R image suport

.github/workflows/checks.yml

@@ -34,6 +34,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install imagemagick
           sudo apt-get install ffmpeg
+          sudo apt-get install libheif-plugin-libde265
 
       - uses: actions/checkout@v3
 

CHANGELOG.md

@@ -6,6 +6,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [2.31.0] - Not released
+### Added
+- Added JPEG Ultra HDR / JPEG_R image preview generation. For supported JPEG
+  images with gain maps, the server now creates a second set of JPEG previews
+  with gain maps and stores them as HDR-specific preview variants.
+
+  Attachments with generated HDR previews expose `meta.hdr: true`, and clients
+  can request the HDR version with `GET /v4/attachments/:id/image?variant=hdr`.
+  The `variant=hdr` query parameter is safe to send for any image attachment: if
+  an HDR preview is not available, the endpoint falls back to the regular SDR
+  preview. HDR preview responses include `variant: "hdr"`.
 
 ## [2.30.0] - 2026-04-29
 ### Added

app/controllers/api/v1/AttachmentsController.js

@@ -194,6 +194,10 @@ export default class AttachmentsController {
         throw new ValidationException('Invalid format value');
       }
 
+      if ('variant' in query && query.variant !== 'hdr') {
+        throw new ValidationException('Invalid variant value');
+      }
+
       const width = 'width' in query ? Number.parseInt(query.width, 10) : undefined;
       const height = 'height' in query ? Number.parseInt(query.height, 10) : undefined;
 
@@ -206,6 +210,7 @@ export default class AttachmentsController {
 
       const asRedirect = 'redirect' in query;
       const withDownload = 'download' in query;
+      const preferHdr = query.variant === 'hdr';
 
       const attachment = await dbAdapter.getAttachmentById(attId);
 
@@ -235,7 +240,8 @@ export default class AttachmentsController {
       } else {
         // Visual types, 'image' and 'video'
 
-        const previews = attachment.previews[type];
+        const useHdrPreview = type === 'image' && preferHdr && attachment.previews.imageHDR;
+        const previews = useHdrPreview ? attachment.previews.imageHDR : attachment.previews[type];
         const {
           variant,
           width: resWidth,
@@ -248,11 +254,17 @@ export default class AttachmentsController {
         response.width = prv.w;
         response.height = prv.h;
 
+        if (useHdrPreview) {
+          response.variant = 'hdr';
+        }
+
         // With imgproxy, we can resize images (except some types) and change
         // their format
         if (
           useImgProxy &&
           type === 'image' &&
+          // imgproxy doesn't support HDR images
+          !useHdrPreview &&
           // We don't need to resize SVGs
           attachment.fileExtension !== 'svg' &&
           // We should not resize (probably) animated legacy GIFs

app/serializers/v2/attachment.ts

@@ -139,17 +139,23 @@ function serializeAttachmentV2(att: Attachment): SerializedAttachmentV2 {
 function serializeAttachmentV4(att: Attachment): SerializedAttachmentV4 {
   const maxVar = att.maxSizedVariant('image');
   const maxPrv = att.previews.image?.[maxVar ?? '-'];
+  const meta: MediaMetaData = {
+    ...att.meta,
+    ...(att.previews.imageHDR ? { hdr: true } : {}),
+  };
 
-  const isMetaEmpty = Object.keys(att.meta).length === 0;
+  const isMetaEmpty = Object.keys(meta).length === 0;
   const isPreviewSizesDifferent = maxPrv && (maxPrv.w !== att.width || maxPrv.h !== att.height);
 
   return {
     id: att.id,
     mediaType: att.mediaType,
     fileName: att.fileName,
     fileSize: att.fileSize,
-    previewTypes: Object.keys(att.previews).sort() as (keyof MediaPreviews)[],
-    meta: isMetaEmpty ? undefined : att.meta,
+    previewTypes: Object.keys(att.previews)
+      .filter((type) => type !== 'imageHDR')
+      .sort() as (keyof MediaPreviews)[],
+    meta: isMetaEmpty ? undefined : meta,
 
     width: att.width ?? undefined,
     height: att.height ?? undefined,