madVR and color management - questions

[Lebowsky]

Those questions might be answered elsewhere, but I couldn't find anything easily so I though I could star a new thread - could be helpful for some people like me.

I have a wide-gamut monitor, Eizo CX240, which is factory calibrated, and I am very happy with the current calibration. There is a built-in self-correction sensor so that you don't need to re-calibrate it from time to time.

I want to use the color management in madVR but I am not sure how to use it.

Do you have to use the 3d lut files? Or is it possible to just somehow "enable" color management? How can I create a 3d lut file? With yCMS? does it require anything from my monitor?

And finally, what is the best way to update madVR without losing settings? delete content of the folder and copy the new files?

[huhn]

I have a wide-gamut monitor, Eizo CX240, which is factory calibrated, and I am very happy with the current calibration. There is a built-in self-correction sensor so that you don't need to re-calibrate it from time to time.
it calibrated for adobe RGB isn't it? if you like it how it is why did you ask this:
I want to use the color management in madVR but I am not sure how to use it.

this is used to correct color so you can create a 3d lut with a colorimeter and correct the colors. if you use adobe rgb you should get totally wrong green colors.

Do you have to use the 3d lut files? Or is it possible to just somehow "enable" color management? How can I create a 3d lut file? With yCMS? does it require anything from my monitor?
you need a colorimeter. you can use madVr without a meter when you know how your monitor is calibrated like bt 2020 but adobe RGB is not part of it.

And finally, what is the best way to update madVR without losing settings? delete content of the folder and copy the new files?

just override it i do it this way.

[Lebowsky]

it calibrated for adobe RGB isn't it? if you like it how it is why did you ask this:

this is used to correct color so you can create a 3d lut with a colorimeter and correct the colors. if you use adobe rgb you should get totally wrong green colors.

I suppose it is Adobe RGB yes. At least it is the mode I using in the monitor menu- it is the one that looks best for Windows and Internet - I don't play games. But I don't have bad green colors in movies. And nothing over-saturated either... at least not to my eye.

Basically I just wanted to make sure that I was doing things the right way... I thought using a non-color-managed movie player would result in bad colors. no?

[huhn]

I suppose it is Adobe RGB yes. At least it is the mode I using in the monitor menu- it is the one that looks best for Windows and Internet - I don't play games. But I don't have bad green colors in movies. And nothing over-saturated either... at least not to my eye.

Basically I just wanted to make sure that I was doing things the right way...
with adobe RGB you are not doing it the right way nearly everything is totally work.
are you aiming for correct colors or what you like?
[/quote]I thought using a non-color-managed movie player would result in bad colors. no?[/QUOTE]

this is true madVR make sure that every input if bt 601, bt 709, bt 2020 and more is shown correctly by converting everything to bt 709 in default settings to the standard a of a normal TV.

[Lebowsky]

I want the correct colors of the input video

[Asmodian]

Using the newest versions of dispcalgui (http://dispcalgui.hoech.net/) is the easiest way to generate a 3DLUT for madVR. This thread (http://www.avsforum.com/forum/139-display-calibration/1471169-madvr-argyllcms.html) at AVSForum is a good guide to start with.

A wide gamut monitor was what first got me interested in color calibration, I really don't like the oversaturated look one gets watching BT.709 on an AdobeRGB display. I was disturbed by the discovery that Windows calibration doesn't handle gamut conversions so everything looks oversaturated all the time, except madVR, Photoshop, and other color managed apps like Firefox.

I will no longer purchase any wide gamut displays.

[huhn]

for correct color you need a colorimeter. if you thing your display has 100 % correct adobe rgb values you can try this 3d lut: http://www.file-upload.net/download-9362374/adobetest.3dlut.html


this 3d lut uses as source rec 709 and target adobe RGB (1998) this may work.
I can't test it so GL.

I'm not a professional in creating 3d luts. I just did it the normal way but switch the profile icm with the adobe RGB that's all.

[Asmodian]

note: your display does not have 100% correct adobe rgb values. ;)

However that is probably a good start.

[huhn]

if I did it right...

[Lebowsky]

Using the newest versions of dispcalgui (http://dispcalgui.hoech.net/) is the easiest way to generate a 3DLUT for madVR. This thread (http://www.avsforum.com/forum/139-display-calibration/1471169-madvr-argyllcms.html) at AVSForum is a good guide to start with.

A wide gamut monitor was what first got me interested in color calibration, I really don't like the oversaturated look one gets watching BT.709 on an AdobeRGB display. I was disturbed by the discovery that Windows calibration doesn't handle gamut conversions so everything looks oversaturated all the time, except madVR, Photoshop, and other color managed apps like Firefox.

I will no longer purchase any wide gamut displays.

ok, so something I don't understang then: how can Firefox display stuff without problem on a wide gamut monitor without a 3dlut, and madVR needs one? Isn't it possible to "force" madVR to "do the same as Firefox does"?

be advised: I'm asking because I have trouble understanding the whole concept :)

[huhn]

he didn't say firefox doesn't need a file too.

the concept is very simple. windwos guess "everything" is perfect sRGB nothing else and "everything" looks right if it the monitor is calibrated for sRGB.

videos are nearly all bt 709 this is very very close to sRGB the gamma is a little bit different they have 100 % the same gamut.

so here is now the problem. everything is created for sRGb but your display displays this with adobe RGB which is simple wrong.

some programms can correct this like firefox with a ICM madVR with a 3d lut adobe photoshop can work in adobe RGB mode(monitors are build for this nothing else).


in short:
windows: show this as sRGB
display: no i do adobe RGB
windows: fine I don't care.

[Lebowsky]

he didn't say firefox doesn't need a file too.

from what I read, it is just a configuration to enable? I tried several tests like http://cameratico.com/tools/web-browser-color-management-test/ and http://www.gballard.net/firefox/

everything I see looks normal. Tagged RGB and untagged sRGB look exactly the same.

[huhn]

these test have nothing to do with your original question.

these test check if image with a correction can be displayed as intended. or with other words can your browser make use of this function.

don't you have an old display just compare.
and if you really want to understand this you should stop looking out for all parts of calibration. this is an very complicated topic. start with on part and get this first and only one way to correct this.

displays have wrong colors that's normal and adobe RGB displays show totally wrong colors with non adobe RGB inputs. and adobe RGB is nearly not used at all. a display with wide color gamut are created to work with specialised software.
the display doesn't know if the input is sRGB or adobe RGB so that's it and windows thinks it is sRGB. it is really that simple.

[Asmodian]

Firefox uses the profile that is assigned in Windows, your monitor might come with one or you can create them with the meter. Windows will only use it to correct the white point (assumes sRGB gamut). Firefox can be told to correct the gamut, note there are a large list of different way to "correct" a gamut. As far as I understand it none of them are most or less correct, simply different. Most of the guide is actually calibrating and generating this profile, there is a tool in dispcalgui that combines the profile with a destination profile into the very precise and specific (and large ;) ) 3DLUT that madVR uses.

People have asked for madVR to be able to read the icm file assigned in Windows like Firefox or Photoshop. The icm file does contain gamut conversion information but it contains it in quite a few different ways, some of them amazingly imprecise. So far Madshi has wanted to keep all the decisions about how to do the conversion outside of madVR, or at least hasn't wanted to implement a CMS other than yCMS. Hence the need to configure a profile and generate a 3DLUT.

You can also use yCMS. It is easy to get the values needed for it with a quick run of HCFR (http://sourceforge.net/projects/hcfr/). This is what I used with my wide gamut display as the 3DLUTs hadn't been implemented yet. It did help a lot but it over-corrected slightly so all my colors were slightly undersaturated. It also went crazy below <20% IRE so it was better to simply leave out all measurements below 20%.

3DLUTs have been much better but if you have below ~1000:1 contrast ratio you might need to experiment with non-BT.1886 calibrations, at least with screens below that I tend to get too bright of shadows following the guide.

Edit: With a wide gamut display and a good 3DLUT madVR can hit pretty much perfect in all measurements I have been able to do, it is quite impressive. At this point it is only with everything else (web video, games, desktop) where a wide gamut display bothers me. A standard gamut display usually cannot do quite as well because at least one primary (blue :p) is not quite the right color, you can subtract but you cannot add.

everything I see looks normal. Tagged RGB and untagged sRGB look exactly the same.

Untagged = sRGB, try tagging AdobeRGB

This is with your own test image, with their (http://cameratico.com/tools/web-browser-color-management-test/) images if you are using a color managed browser and a good profile for your display installed you should see everything the same except the "How far from sRGB is your display color gamut?"

If you see that the same you don't have a wide gamut display. ;) er, or you aren't color managed at all.

[Lebowsky]

these test have nothing to do with your original question.

these test check if image with a correction can be displayed as intended. or with other words can your browser make use of this function.

exactly. so can't mpc-hc + madVR make use of this function, just like a browser?

Firefox uses the profile that is assigned in Windows, your monitor might come with one or you can create them with the meter. Windows will only use it to correct the white point (assumes sRGB gamut). Firefox can be told to correct the gamut, note there are a large list of different way to "correct" a gamut. As far as I understand it none of them are most or less correct, simply different. Most of the guide is actually calibrating and generating this profile, there is a tool in dispcalgui that combines the profile with a destination profile into the very precise and specific (and large ;) ) 3DLUT that madVR uses.

People have asked for madVR to be able to read the icm file assigned in Windows like Firefox or Photoshop. The icm file does contain gamut conversion information but it contains it in quite a few different ways, some of them amazingly imprecise. So far Madshi has wanted to keep all the decisions about how to do the conversion outside of madVR, or at least hasn't wanted to implement a CMS other than yCMS. Hence the need to configure a profile and generate a 3DLUT.

You can also use yCMS. It is easy to get the values needed for it with a quick run of HCFR (http://sourceforge.net/projects/hcfr/). This is what I used with my wide gamut display as the 3DLUTs hadn't been implemented yet. It did help a lot but it over-corrected slightly so all my colors were slightly undersaturated. It also went crazy below <20% IRE so it was better to simply leave out all measurements below 20%.

3DLUTs have been much better but if you have below ~1000:1 contrast ratio you might need to experiment with non-BT.1886 calibrations, at least with screens below that I tend to get too bright of shadows following the guide.

Edit: With a wide gamut display and a good 3DLUT madVR can hit pretty much perfect in all measurements I have been able to do, it is quite impressive. At this point it is only with everything else (web video, games, desktop) where a wide gamut display bothers me. A standard gamut display usually cannot do quite as well because at least one primary (blue :p) is not quite the right color, you can subtract but you cannot add.

I don't have a colorimeter, so I don't see yet how I could create a profile :( I bought the display sepcifically without the colorimeter, because it had tremendously great pre-calibration reviews everywhere, and I wasn't interested in this. so you're saying I'm screwed?


Untagged = sRGB, try tagging AdobeRGB

This is with your own test image, with their (http://cameratico.com/tools/web-browser-color-management-test/) images if you are using a color managed browser and a good profile for your display installed you should see everything the same except the "How far from sRGB is your display color gamut?"

If you see that the same you don't have a wide gamut display. ;) er, or you aren't color managed at all.

I promise you there is not difference at all. If I switch my monitor between AdobeRGB and sRGB modes, there is still no visual difference in the images. HOWEVER, in AdobeRGB modes, the colors in the images are a lot more poppy, and much more dull in sRGB. But there is no difference between ProPhotoRGB tagged image vs. sRGB tagged image.



My understanding was: input can be of any type. A "normal" application (let's say a game) will output it to the screen in sRGB. So if the screen is in sRGB you will see what is intended (not taking into account the difference between "perfect sRGB" and what a screen actually displays, maybe 97-99%). If the monitor is wide gamut, it is the application's job to convert the output, so that it sends "wide gamut" values that correspond to the sRGB values, so that the colors are still correct. So why can't it be activated with just a click? I understand, if you create a profile with a colorimterer, then it will be give you the "exact" wide gamut values from the screen. But aren't there simply "default" conversion values that can be used? Theoretical wide gamut values, or something like that? Or is that what you were referring to as the profile in Windows?

[Lebowsky]

OK I get it now. Eizo offers the default profiles for free to download.

edit: and now the ProPhotoRGB tagged image vs. sRGB tagged image test looks totally different :D but the rest is perfectly uniform. so yeah, color management was not enabled. hrm.. :rolleyes:

so now how can I use this default profile with madVR? Can I create a 3D LUT file from it, and if so with which application?

edit2: ok, one step further ;) seems like dispcalGUI can create a 3d lut file from an icm profile. Which source of the provided icm profile should I choose if the goal is to load the 3d lut in madVR? BT.709? sRGB?

[huhn]

go to 3d lut creating.

set source as bt 709
set target to the new icm.
select madVR format 3d lut.
about bt 1886 this is your choice not a simple topic.
or just try the 3d lut i posted above.