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My work PC (Windows 7 Pro x64) has dual monitors and a very washed-out looking default color profile. I get around this by running the NVIDIA Control Panel and setting the gamma slider to about 0.50 and applying the changes. Works great.

The problem is that I work remotely roughly half the time, and when I am at home I use Remote Desktop to connect to the work PC. When I come back to the office, the gamma settings reset to their default, washed-out levels, even though the control panel gamma slider is still at 0.5.

My "fix" is to open the control panel and move the slider for each monitor ever-so-slightly to apply new gamma settings. It works but it's very annoying to have to do every day.

I see people with similar issues:

nVidia Control Panel resets Gamma setting after restart

my gamma automatically changes coming out of standby

Though we have the same problem, I'm interested in scripting a solution to this. Ideally, I'd like a script to run on login that will force my gamma settings to where I want them.

Is there a standard command line way to apply gamma settings in Windows 7?

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up vote 1 down vote accepted

It is possible to do something like this using scripting utilities like AutoIT, C# and other programming languages. Any language that can interface with gdi32.dll, for example, should be able to accomplish this task.

Here's an example found for AutoIt:

Func _SetGamma ( $vRed=128, $vGreen=128, $vBlue=128 )
    Local $n_ramp, $rVar, $gVar, $bVar, $Ret, $i, $dc
    If $vRed < 0 Or $vRed > 386 Then Return -1
    If $vGreen < 0 Or $vGreen > 386 Then Return -1
    If $vBlue < 0 Or $vBlue > 386 Then Return -1
    $dc = DLLCall ( "user32.dll", "int", "GetDC","hwnd", 0 )
    $n_ramp = DllStructCreate ( "short[" & ( 256*3 ) & "]" )
    For $i = 0 to 256
    $rVar = $i * ( $vRed + 128 )
    If $rVar > 65535 Then $rVar = 65535
    $gVar = $i * ( $vGreen + 128 )
    If $gVar > 65535 Then $gVar = 65535
    $bVar = $i * ( $vBlue + 128 )
    If $bVar > 65535 Then $bVar = 65535
    DllStructSetData ( $n_ramp, 1, Int ( $rVar ), $i  ) ; red
    DllStructSetData ( $n_ramp, 1, Int ( $gVar ), $i+256 ) ; green
    DllStructSetData ( $n_ramp, 1, Int ( $bVar ), $i+512 ) ; blue
    $ret = DLLCall ( "gdi32.dll", "int", "SetDeviceGammaRamp", "int", $dc[0], "ptr", DllStructGetPtr ( $n_Ramp ) )
    $dc = 0
    $n_Ramp = 0
EndFunc ;==> _SetGamma ( )

The source for this can be found here: TinyBrightnessControler v

it would be very little work to compile that into an executable file that can run in a start-up script.

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AutoIt is unassuming enough that I have no issue just clicking the tray icon to change my settings - TinyBrightnessController is perfect right out of the box! Thank you! – Stefan Mohr Feb 2 '12 at 16:55

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