v1.0.31

1.0.31.0 - 2026-09-09

• Fixed crop export to calculate SDR preview bounds from the source image's oriented pixel dimensions instead of a potentially stale HDR renderer texture. Crop bounds are now centrally clamped for landscape and portrait images, and failed or duplicate crop saves now report a clear dialog without starting overlapping exports.
• Stabilized the shared-operation cancellation regression test used by the release build so it waits for the operation to register its cancellation callback before canceling its final waiter.

Install

1. Download HdrImageViewer-1.0.31-win-x64-portable.zip.
2. Extract the zip to a normal folder, for example C:\Apps\HdrImageViewer.
3. Run HdrImageViewer.exe.

Requires the x64 .NET 10 Desktop Runtime and Windows App Runtime 2.2. No certificate installation is required for the portable zip. Windows may show a SmartScreen warning because this GitHub build is unsigned.

Recommended Install

For most users, install the Microsoft Store version so Windows handles signing and updates.

Optional Format Tools

Most common formats work out of the box. JPEG XL preview and some HDR export formats use external command-line tools when they are available.

Install optional tools with MSYS2 UCRT64:

winget install --id MSYS2.MSYS2 --source winget
C:\msys64\usr\bin\pacman.exe -Syu --noconfirm
C:\msys64\usr\bin\pacman.exe -S --needed --noconfirm mingw-w64-ucrt-x86_64-libjxl mingw-w64-ucrt-x86_64-libavif mingw-w64-ucrt-x86_64-libheif

Restart HDR Image Viewer after installing. The app auto-detects tools in C:\msys64\ucrt64\bin and also checks PATH.

• JPEG XL preview: jxlinfo.exe and djxl.exe from libjxl.
• JPEG XL / AVIF / HEIC HDR export: cjxl.exe, avifenc.exe, and heif-enc.exe when installed.
• Ultra HDR JPEG export: advanced users can place ultrahdr_app.exe on PATH.