Ok, so I have everything “installed” in the right directory, and the screenshots do save in the .jxr format. After taking a screenshot, does the original .jxr file become edited or does this script write a new file? And do I need to actually double click and run the watch file before?
EDIT: Found what I was doing wrong. I needed to actually run the watch file and keep it running. Now I’m seeing the -sdr file being produced. So cool! Thank you so much!!
Awesome, I’m glad it’s working out for folks! When I have time I’ll try and put a little GUI frontend on it so it’s less cumbersome to run, but for now it does the job. 
Hi, I don’t use Microsoft Flight Simulator but this is the only detailed reference I could find on this subject. I’m processing jxr files from the Game Bar. The script above is great but I can’t get it to produce anything much more different from the png from Game Bar. I’ve been using IrfanView to open the jxr which produces much more what I’m looking for; a more traditional photography type HDR where there is increased detail and the full range is visible from dark to light, see the top of michaelzfreeman dot org … But IrfanView has no way to adjust the way its processing. Anyone know of any other open source/free software ? Cheers.
Offhand I don’t know anything that does the fancier, local/context-sensitive contrast effects on this sort of input file.
If you have an Adobe subscription there’s a nice tool in Photoshop for doing HDR manipulation (I can’t for the life of me remember the name of the tool, but I remember finding it fairly easily). The tricky part is getting it to read the .jxr input files – even with a plugin it was basically just clipping all input channels at 1.0, so you couldn’t work with the picture.
I think you could use the current version of hdrfix as a first stage, to effectively repack the data you want to work with into the 0…1.0 range. Then you can load that into Photoshop, or another tool; you’ll lose a little color resolution from saving to an 8-bits-per-channel format, but most of the time there’s enough noise or dithering on screen already that there won’t be visible banding.
Thanks. I eventually found Fhotoroom in the Microsoft Store which can open JXR and has HDR tone mapping. Still experimenting with it.
what about a video HDR uploaded on YouTube for the non HDR owners ?
In my experience YouTube can consume the HDR HEVC .mp4 files produced by the NVIDIA overlay, and makes a pretty acceptable SDR conversion from it. The main problem I’ve had is that the Windows default photo/movie viewer/editor’s trim mode won’t let you trim (it seems to work, then gives a mysterious permissions error when you say ‘save copy’). Thus for trimming prior to uploading, I’ve had to either use ffmpeg (manually on the command line) or load the file on a Mac where the default movie player’s trim tool works correctly on these files.
However, I am having some intermittent troubles with the latest NVIDIA driver where screenshots and/or video recordings stop working correctly, or the video recording pulls from the wrong screen. Presumably these are driver regressions and will I hope get fixed soon…
I recently tried capturing HDR with GeForce Experience, opening the JXR in GIMP with the JXR plugin, and the results were less than satisfactory. (I know why.)
I’m going to try your software. Have there been any changes/updates since your last post back in 2021? At this point I’ve given up on HDR screencaps, and just turn HDR off in the sim when I know I want to take screenshots. The resulting pics look good enough, but I’d like to capture HDR if possible without jumping through seemingly endless hoops. Your software sounds promising.
Help me Obi-Wan, you’re my only hope.
I’ve tweaked its internals and the default options, but it still works pretty much the same – it can take an HDR JXR, apply some brightness/gamma/level controls and tone mapping, and write out a regular JPEG.
I keep meaning to go back to it, especially since I’ve improved my video processing techniques (using ffmpeg filters, which are quite capable), but haven’t had a chance to get in and rip its guts out yet to support both stills and video. 
Feel free to DM me with any questions or problems you have with the current version, and I’ll do my best to help!
Thanks! I’ll review this thread for instructions on what I need to download and install. I’ll let you know how it goes.
Quick update. I had an issue with the v1.0 zipfile linked to above. Vibstronium responded to a DM very quickly and gave me a link to v1.0.5, which worked. I installed the .exe and .bat files into my screenshot folder, and when I used GeForce to capture an HDR file (.jxr file) the batch file did exactly what it was supposed to - it saw the file and converted it to a .jpg. Kudos to the author for putting in the time and effort to give us this tool, which allows us to capture good screenshots without having to either [a.] switch to SDR mode in the sim, or [b.] figure out how to convert the .jxr files manually.
Here’s the link to the v1.0.5 zip file: https://github.com/brion/hdrfix/releases/tag/1.0.5
And here’s the first screenshot I took. Looks good to me.
Hey, thanks for the great work! Does this also work with screenshots created with OBS (also jxr files)? Whenever I start the exe in the windows video folder it just instantly closes the window (could be a windows write access error as well, I suppose). Again thank you for the contribution to the FOSS family 
It ought to work with jxrs saved from OBS also; if you find it doesn’t, DM me and I’ll let you know where to email me a sample file I can test with to fix it. 
The primary problem seems to be that the exe is crashing regardless of where I put it.
Does it have any dependencies to NVidia drivers/packages? I have an AMD card (6900XT). Can’t find a log to debug either.
It doesn’t use any graphics drivers, it’s a pure-computation command-line program; the only dependency is the Microsoft Visual C++ runtime which is usually pre-installed.
If you need to download this you can get it from Microsoft here; grab the version 170 (for Visual Studio 2015, 2017, 2019, and 2022) for X64 from:
Make sure you’re using it correctly though; it’s a command-line program so if you just double-click the .exe from File Explorer it’ll pop up a message listing the arguments, then immediately exit.
