HDR + WCG Image Viewer

## About the Project This is a Universal Windows Platform (UWP) app that uses [DirectX Advanced Color](https://aka.ms/directxhdr) to decode and render HDR image formats at the best available quality on a supported HDR10 display. Supported formats include: * OpenEXR * Radiance RGBE (.hdr) * JPEG XR (including Xbox and Windows variants) * HEIC with HDR10/BT.2100 data * AVIF with HDR10/BT.2100 data * **EXPERIMENTAL:** Apple HDR GainMap images using HEIC and JPEG * JPEG, PNG and other SDR formats with wide gamut and/or color profile information The app performs luminance display mapping/tone mapping to adapt an HDR image to the capability of the display. It also includes some useful tools for HDR developers such as rendering the image luminance as a colorized heatmap, or forcing an image to be interpreted with a specific colorspace (for example, PNG images encoded as HDR10). ## Running the app The minimum requirements to run the app are a recent version of Windows 10 or 11 (19H1 or greater) and a GPU that supports DirectX 11. You should also update your graphics (WDDM) driver. ### Display hardware If you use an SDR display the app will use tone mapping to render any HDR images to the best of its ability. You will obviously need a Windows-compatible HDR display to experience a benefit from HDR images. HDR displays vary greatly in quality - low quality models offer no real benefit over SDR and in fact often screw up color and graphics rendering as to make it look *worse* than SDR. For best results a certified display is ***strongly*** recommended, including: * [VESA DisplayHDR 500 or above](https://displayhdr.org/certified-products/) * [AMD FreeSync Premium Pro](https://www.amd.com/en/technologies/freesync-hdr-games) * [NVIDIA G-SYNC and G-SYNC Ultimate](https://www.nvidia.com/en-us/geforce/products/g-sync-monitors) ### Command line usage If you are loading an image using the `-input` argument you must invoke HDRImageViewer from the directory containing the image you wish to load - UWP apps launched from a command line only have access to files within the working directory. #### Parameters `-f` Start in fullscreen mode `-h` Start with UI hidden `-forcebt2100` Force images to use BT.2100 PQ color space (BT.2020 primaries, ST.2084/PQ transfer function) `-input:filename` Load `filename` **Note: Filename must be relative to the current working directory as HDRImageViewer only has access to that directory.** `-colorprofile:r_x,r_y,g_x,g_y,b_x,b_y,w_X,w_Z,gamma` Use a custom color space defined by RGBW primaries and gamma * `r_x,r_y,g_x,g_y,b_x,b_y`: CIExyY x and y coordinates of the red/green/blue primaries. * `w_X,w_Z`: CIEXYZ X and Z coordinates of the whitepoint, normalized to Y = 1.0 * `gamma`: Enumeration, use 0 for 2.2/sRGB, 1 for 1.0/linear. BT.2100 PQ transfer function is not yet supported, use `-forcebt2100` instead. `-rendereffect:[effect]` Force a render effect. Valid values are: * `none` * `hdrtonemap` * `sdroverlay` * `maxluminance` * `luminanceheatmap` #### Example `HDRImageViewer.exe -f -h -input:myimage.jxr` ## Compiling the app You'll need [Visual Studio 2022](www.visualstudio.com) with the following workloads installed: * `Desktop Development with C++` * `Universal Windows Platform Development` * In *Optional Components*, make sure `C++ (v143) Universal Windows Platform tools` is checked. (VS2019 probably works, too, but this is untested) ### Manually including the libheif package The repo contains a copy of [libheif](https://github.com/strukturag/libheif) built using [vcpkg](https://github.com/Microsoft/vcpkg/) and exported into a local NuGet package at `\libheif-vcpkg\vcpkg-export-20210528-221932.1.0.0.nupkg`. Libheif is consumed by HDRImageViewer as a dynamic link library to comply with requirements of the LGPL license. You must manually add the `libheif-vcpkg` directory to Visual Studio's list of NuGet package repositories: 1. In Visual Studio, go to `Tools > NuGet Package Manager > Package Manager Settings`. 2. In the `Package Sources` page, add the `libheif-vcpkg` directory as a new source. Visual Studio should show something similar to: ## Acknowledgments This app includes source, object code, and/or techniques from many excellent sources, including but not limited the following: * [D2DAdvancedColorImages SDK sample](https://docs.microsoft.com/en-us/samples/microsoft/windows-universal-samples/d2dadvancedcolorimages/). * Rick Manning's [HDR Image Viewer](https://www.microsoft.com/store/productId/9NPSWXVL7W40). * [DirectXTex](https://github.com/Microsoft/DirectXTex). * [OpenEXR](https://www.openexr.com/). * [zlib](https://www.zlib.net/). * [libheif](https://github.com/strukturag/libheif). 3rd party licenses can be found in the `3rdparty` directory.