So I have one PC connecting to monitor A and B through DP ports. However, monitor A also connects to the same PC over an HDMI port with a KVM switch in between. Monitor A, therefore, is identified as two displays in the system, but as they are in duplicate mode, still shows same image.

Here comes the problem. When I have monitor A connects only through HDMI or DP, the 3dlut works great. But if I connect it through HDMI and DP at the same time, the color is washed out.

The color of monitor B is not affected though.

It appears dwm_lut is no longer working on Windows 11 22H1 build 22000.706. I'm wondering if Microsoft rolled some of the changes that break 22H2 back into 22H1 22000.706.

Hi,

Thanks for making this program! When I apply a 3dlut, Adaptive Sync is disabled. I do not game, but the windows Movies & TV UWP video player uses Adaptive Sync to match the display + video framerates to eliminate judder. Is this something that can be fixed?

DwmLut has some useful command arguments right now. However, if user wants to switch between different lut files via command, he has to edit config.xml then run with -apply.

This is attempt to fill the void by supporting two extra arguments "-sdr" and "-hdr". Example:

DwmLutGUI.exe -sdr "1:C:\luts\1\sdr.lut;2:C:\luts\2\sdr.lut" -hdr "1:C:\luts\1\hdr.lut;2:C:\luts\2\hdr.lut" -apply -exit

This example sets monitor 1's SDR lut to "C:\luts\1\sdr.lut", and monitor 2's SDR lut to "C:\luts\2\sdr.lut". Similar to HDR luts.

Also, paths set via this way does not permanently change the content of config.xml. This suits the "temporary" nature of this argument.

What do you think?

When playing DRM protected content, HDCP activates and causes one or two black flashes of the screen. The LUT is unloaded. The application status becomes "Inactive". And the video begins playing.

As a reminder, High-bandwidth Digital Content Protection (HDCP) is used for DRM on video streaming services.

Instructions:

1. Launch dwm_lut and press Apply
2. Log into a video streaming platform, like Netflix, Amazon Prime, BBC iPlayer, etc.
3. Play a video (I recommend testing on Firefox. It shows a HDCP icon in the address bar whenever it kicks in.)

I don't know what you could do about this. Maybe reactivate once HDCP is no longer active?

On Windows 11. Says active but no change in color output is seen. Oddly with a generic Microsoft driver active did work as expected. According to GPU-Z the generic driver supports OpenGL 2.1, the Intel driver supports OpenGL 3.1 with many report on the web talking about wonky OpenGL support.

Any testing I can do? Let me know.

Hi ledoge,

I'm getting the following error when I hit the Apply button, after selecting a LUT to apply. Any ideas on what might be causing it?

For context, the very first time I ran the tool it worked fine, then after trying to load a different LUT file it started throwing this error and I wasn't able to get it working again.

My OS details:

Edition Windows 11 Home Version 21H2 Installed on ‎23/‎08/‎2022 OS build 22000.856 Experience Windows Feature Experience Pack 1000.22000.856.0

Applying the LUT while the Netflix app is running causes the screen to become pixelated and unusable. Disabling the LUT immediately resolves the issue. I also tried with the native Hulu and Amazon Prime Video apps and it did not reproduce. Not a big deal to turn it off, though.

Example of the issue https://photos.app.goo.gl/r4ta6sHf8H8NBUUZ8

I found it looks different when I apply my calibration LUT to LUT stress test image in Resolve, compared to loading it into DwmLut. I can't show it, because (luckily) screenshots aren't affected by the LUT, but it makes shadows desaturated, compared to applying the LUT in Resolve. Also it looks like there is some downsizing of the cube size of the LUT before applying the LUT. Probably this is the reason for the artifact I got?

I hope GitHub issues are the right place for feature requests, if not, feel free to close this.

I stumbled upon this repo by accident when I was calibrating my friend's brand new OLED TV last weekend and I am absolutely loving it so far. I can't believe I didn't find it sooner, because I posted around 5 years ago on ReShade's forum trying to get ReShade to do what you are doing by hooking the DWM and have been desperate to find something since then.

Which leads me right into this request. Web content, specifically YouTube, is often rife with banding and the video rendering pipelines of desktop browsers like Chrome and Firefox are optimised for performance and battery life and so do all levels conversion in 8 bit, making the banding even worse.

I already noticed a reduction in banding when using dwm_lut over the standard GPU gamma table, but the inclusion of a debanding shader would make it even better.

ReShade already includes an open source debanding effect, but it is written in ReShade's own effect language which according to its author is based on HLSL. I hope porting it to actual HLSL is easy.

https://github.com/crosire/reshade-shaders/blob/slim/Shaders/Deband.fx

Thanks!

Hi there,

I'm wondering if PNG LUTs (like those used for ReShade) can be supported. I haven't been able to find a tool that can convert my PNG LUTs into .CUBE.

My laptop, even when running off of a power brick, cuts all program frame rates in half when this program applies a LUT. I am running a dedicated graphics card through an Intel graphics adapter. Is there a fix for this?

Read all the information from the DisplayCAL forum and I still don't understand the recommendation to use the Windows built in sRGB profile as the display profile.

dwm_lut applies the lut to everything displayed on screen but color managed apps would still benefit from an sRGB profile created for the display with DisplayCAL no?

My reasoning is a program needs to know some display characteristics to render stuff correctly otherwise they assume some standard and a sort of reference display and squeeze all pixels displayed into that standard. In most cases they assume a 1:1000 contrast a gamma 2.2 or sRGB tone curve ..., obviously a display is from factory most of the time different than this assumed common denominator standard.

So wouldn't it make sense to create a display profile aka. sRGB in DisplayCAL use it as default ICC profile generate 3DLUT from it with a preferred gamma of 2.2 as an example and apply the 3DLUT with dwm_lut?

My only concern with this approach is vcgt that might be applied 2x (Display CAL profile loader + dwm_lut), not sure if it would be the case. I could set tone curve as measured in DisplayCAL when creating the profile to avoid this.

What are your thoughts on this topic?

My aim is to give apps info about the display like contrast white point and so on via ICC so they don't assume stuff while globally applying a 3dlut on top.

It would just be something like a pixel value going from: 0.2343 -> 0.2143 (what the app thinks it should be in sRGB --> 0.2142 (what the actual lut applied would show at the end) My concern is app doing this In file 0.2343 -> 0.2452 (some assumptions in the app without profile) -> 0.2243 final value based on wrong value from the app when dwm_lut is applied.

Hope you get the example and looking forward to your answer.

I must be doing something wrong here....

So, I have a benq SW270C.

1. I started windows fresh. No DisplayCAL profile loader running, no dmw_lut running, all color profiles removed in windows.
2. I hardware calibrated the screen with Palette Master Element to it's native color gamut.
3. I ran a Calibrate & Profile in DisplayCAL, which generated a ICC profile
4. I loaded that profile into windows and I ran a Verification step in DisplayCAL. Everything passed, calibration looking good.
5. After loading the ICC profile in windows, color managed application behave like they should, windows desktop and other application show over saturated color, as expected.

So far so good and I've been doing this ever since I got this monitor. But then...

1. I turn that ICC profile into a 3DLUT using DisplayCAL, using it's default setting, and save it to a file.
2. I remove all ICC profiles from my monitor in windows's color management.
3. I make sure DisplayCALs profile loader isn't running.
4. I start dwm_lut, load the 3DLUT cube file and assign it to my monitor as the SDR profile
5. The windows desktop isn't over saturated anymore, and it looks like color managed applications are also working as expected. No washed out colors, no overly saturated colors. Can't judge color correctness though.

But when I run DisplayCAL's Verification step again, the report shows the colors are completely wrong. Here's the summary.

Criteria | Nominal | Recommended | # | Actual | Result -- | -- | -- | -- | -- | -- Measured vs. assumed target whitepoint ΔE*00 | <= 2 | <= 1 |   | 4.61 | NOT OK ✖ Measured vs. display profile whitepoint ΔE00 | <= 1 | |  | 4.95 |   Average ΔE00 | <= 1.5 | <= 1 |   |  5.39 | NOT OK ✖ Maximum ΔE*00 | <= 4 | <= 3 | 322 | 11 | NOT OK ✖

What's happening here? Why is DisplayCAL's verification step failing?

Did I miss something fundamental in my workflow above?