Which .icm file to use when HTPC ->Plasma TV?

I'd turn off everything you have turned on. Especially dynamic contrast, that's especially bad.

The ICM files don't do anything to improve your image quality, they only work in color managed apps, like photoshop, ect... Video playback software like TMT completely ignores them.

Windows doesn't support LUTs embedded in ICC/ICM profiles, you'll need to calibrate those separately.

MPC HomeCinema support LUTs embedded in ICC/ICM profiles.

MadVr also supports 3DLut calibration (using yCMS) but it's underdeveloped.

It's not entirely true that Video playback software ignores the .icm file. Endemically, yes, JRiver MC (for example) ignores the .icm file, but if you set the monitor profile to work system-wide by default, then the video playback software will have to "use" the monitor profile because it's part of the system, it can't stop it from being used. And as in the recent thread that I started a few days ago, it does help to have a very correct profile if you are using a HTPC for playback. I would be careful about downloading profiles because there are many variables you have to set correctly on the monitor itself to work with the profile. It would pay to save up for something like an i1 display pro. See the Sony monitor thread I started a few days ago.

That's not true.

Windows desktop, and by extension all direct-show filters, do not use ICM profiles.

Having an ICM setup as the default working profile does not mean that it applies correction, it simply means ICC/ICM aware apps will default to that profile.

I do know that 1 single video app, MPC-HC, can use ICC. So Windows media player, windoes media center, xbox media center, zoom player, cyberlink powerDVD, arcsoft TMT, corel winDVD, ect... DO NOT USE ICC, and CANNOT BENEFIT FROM icc in any way.

The list of software that doesn't work is extensive.

If you like menus with your blu-rays there are ZERO software solutions that work with ICM.

Anyone who thinks ICC profiles are a solution for video playback is either willing to conform to the single piece of software that supports them, or doesn't understand that they aren't actually getting a benefit from ICC.

I hate to argue with the Spectracal developer! Here is the evidence that I am right: As I mentioned in the Sony monitor thread that I recently started, INITIALLY, the icc profile that I had created in the i1 was not being used. The first evidence is that the Joe Kane grayscale ramp showed a significant green tinge in the low mid level section of the chips. After that I went straight into the windows color management setup and after a bit of work (described in that thread) I was able to enable the profile system wide. And I am confident it is working with JRiver media center, as evidenced by a big change in the Joe Kane grayscale ramp, which now looks entirely grey and neutral. I can only conclude that it is possible to use icc profiles with video playback apps.

If necessary, I'll take screen shots of before and after of my monitor to demonstrate.

It's the graphics card LUT.

You can modify the gamma and white point, but not the gamut or color decoder issues.

Not just that but they are handled separately by windows. You can change the ICM profile without replacing the LUT, or vice versa.


The LUT is applied in the graphics card at the scan out stage, so it does have a system wide affect. It's not that calibrating your PC doesn't benefit video content, it's that ICC profiles don't benefit video content. All good PC calibration software packages do both, but they also leave a tray app running, that tray app is what is managing the LUT, which is why you see changes in the desktop.

Some time back a component called a VCGT was added to ICC / ICM profiles.
This is an optional component, and is just a 1D RGB LUT, so is can change grey scale / colour temp / white point.

When a PC profiling system generates an ICC / ICM profile it does include gamut matrices too.
But theses are only used by software applications (such as Photoshop, etc).

You can actually manage the VCGT separately from any ICC / ICM profile with something like SpaceMatch DCM (which does a lot of other things) or via CalibrationTester.exe, which you can find via a Google).

This approach can help, as ICC / ICM profiles often cause issues with other software applications that attempt to use the profile data to perform their own internal colour correction.
It also means you can load the VCGT and then not have any application running.
The VCGT can be loaded via Windows Scheduler for example.

For calibration in this industry (film and TV) I really suggest avoiding ICC / ICM profiles.

Steve

VCGT is not an ICC spec, it uses the fact that ICC profiles support arbitrary tags.

Feel free to review the ICC spec: http://www.color.org/specification/ICC1v43_2010-12.pdf

Also if you actually wrote code that did PC calibration, you would know windows doesn't support the VCGT tag and you have to load that information separately via the windows API.
Edited by sotti - 2/26/13 at 1:12pm

We do do Windows ICC calibration, and it does load the tag - it even flags when a vcgt is available

The vcgt was actually 'nicked' from Mac!

Just checked - Windows 7 uses the vcgt - XP and Vista require separate colour management software to be downloaded.

So does the PC calibration software offered by SpectraCal provide grayscale, gamut, gamma and white point for video playback using the standard Windows Media Center DXVA and EVR renderer?

Yes but you must go into control panel and go to the Color Management profile and then go to the advanced tab and then click the Use Widnows Display calibration check box.

Which is not enabled by default and does not have an API to enable, therefore it requires the user to go in and make the change specifically.

Like I mentioned above, windows does not do this in any reliable way, so all good color calibration apps for the Windows use a tray app that handles loading the LUTs directly.

It's the only way you can do it if you want to have an ordinary user install your software and be successful. Not to mention a lot of people used XP or Vista where that features is not available at all.

Our software manages the graphic's card LUT and provides an ICC profile.

DXVA and EVR renderers do not have built in support for ICC. Unless the specifically registered renderer provides custom support for using ICC, the profile will not effect the video output.

The graphics card LUT does provide white point and gamma correction on a system wide basis, so all content, DirectX, DXVA, EVR, and desktop apps all benefit from having the LUT calibrated.

OK, here's how it's done! It took me the rest of today to figure this out. The gentleman from Spectracal was right. Joel (from Spectracal) was correct that JRiver (and other video playback programs) normally ignore the profile and yes they do. But there is a way to use icc monitor profiles with a video playback program and just the i1 Display Pro! I figured out how to do it with just the i1Display software and some utilities available free from XRite; so I wouldn't have to buy another calibrator from Spectracal (sorry guys). I think this post should be made a sticky.

Damn Windows, this would be so much easier on a Mac. When I started this investigation I thought I had licked the problem, but on a reboot the monitor calibration was lost. So I had to do a little research and come up with the recipe below.

The way to do it (as mentioned by Joel from Spectracal) is to load the gamma curves into the Look Up Table (LUT) of the graphics card each time you start up. I have an AMD graphics card, which does not allow loading icc profiles directly. The following procedure may not be necessary with NVIDIA graphics cards as apparently they have a method of initializing with an icc profile.

1) The monitor profile must be applied to the look up table (LUT) of the graphics card each time that windows is restarted. Since JRiver won't use windows' icc profile, then the profile (or its curves) must be loaded directly into the graphics card!
2) The LUT (lookup table) in the graphics card must be reinitialized with the icc profile (gamma curves) each time that windows is restarted, or the monitor profile will not be used by your video playback software.
3) Download from the i1 site "Eye One Match Software". Most of this software is not appropriate for the i1 Display Pro and will not function. However, XRite includes one gem which is essential (and apparently does not come with the regular i1 Display Pro software). This is a LUT loader called "CalibrationLoader.exe". Put a shortcut of this application in the windows startup folder.
4) Also download from the i1 site the "Calibration tester", known as pm5_calibration tester. You can use this to confirm that your graphics card has loaded your monitor profile, and also to disable it to see a before and after demonstration. You can then reload the monitor profile using "Calibration Loader" to test it. Both of these files are found at http://www.xrite.com/product_overview.aspx?Action=support&ID=758 at the xrite site.
5) Make sure that your i1-generated monitor profile is the default system profile in the color management section of windows. This is the profile that will be loaded by "CalibrationLoader".
6) If you are using Photoshop or other application which can use a monitor profile on this same machine, be careful that you don't get "double correction". You may have to clear the LUT override on the graphics card in some circumstances. And if you are switching back and forth frequently between Photoshop and JRiver (or similar video playback software) you might be able to set up an autohotkey macro to perform the switching tasks.

Attached are two screenshots from "Calibration Tester" on my machine. One of the shots is after loading a fake "crappy profile" that I generated using the Sony monitor set for "vivid" to fool i1. It's great for testing and proving that your correct monitor profile has been loaded after restart. The other screenshot is the results of the i1Profiler, it is my icc profile that I'm now using to get beautiful-looking and accurate video from JRiver. When the LUT is cleared with the reset button in Calibration tester, the graphics card is neutralized, I cannot see the 2% chip in the pluge pattern, and the grayscale looks uneven and color-tinted in spots. When I load the "crappy profile" everything looks crappy so you can really see the effect. Finally, when I load the correct profile, all the chips are neutral gray and the pluge pattern looks correct. This holds through reboots! Hooray.

I can only conclude that I've conquered the problem and that the i1Display Pro can be used with video playback software.
Edited by bobkatz - 2/26/13 at 2:59pm

for white point and gamma, if you need gamut calibration, you'll need to find another path.

Do you have Spectracal available for Mac as well? Joel, how long have you had this feature (generating icc profiles)? When I called you a few years ago you said there was no way to use the i1Display Pro that you include with your software to set up monitor profiles. And I enquired of XRite and they would not sell me an upgrade license so I could use the unit you sell for both purposes. So I went with the i1Display Pro direct from XRite.

If only I had known Spectracal had this flexibility a few years ago I would not have bought the i1 Display Pro at that time, I would have bought the full kit from Spectracal. That's because I not only wanted to calibrate the home theatre, I also wanted to calibrate the Mac monitors for photography with Lightroom and Photoshop. Sorry about that...


Bob

Dear Joel:

How long have you included icc support in your software? I was not aware of it. Do you support Macs as well? There would be no need for an LUT initializer on Macs, of course, just make the profile and assign it to the monitor. Macs are much friendlier to graphics professionals.

I believe that I called both Spectracal and Chromapure a few years ago enquiring if I could use the included colorimeter for both home theatre calibration and also generating icc profiles for use on a Mac for photography. I also enquired of XRite to see if I could purchase an upgrade license to upgrade the i1DisplayPro that would allow doing both. Instead I learned I would have to buy two redundant colorimeters and that just busted my chops. So I just bought the i1Display Pro for the Macs and did the home theatre monitor manually.

If only I had known you had that facility I would have been happy to purchase Spectracal (or your competitor's product if it had that facility)!

Dear Joel: Please elaborate. I don't know what "gamut" is. I am happy with the visual results as viewed with the Joe Kane disc, however!

There exists an application called Upsilon Mixer that does gamut, gamma, white point and grayscale for Windows DXVA and EVR. It was floating around in beta for along time but has limited meter support. It was free in beta but is $50 US dollars now. You can try before you buy but it watermarkets the display. I am tempted to give it a whirl now that I have an i1 pro which is supposely supported. It site licenses you for non-commercial use.

This is the kind of app I would like to see only with a decent size cube and support for other renderers like madVR transparently and proper support for more current meters with meter profiling.

The i1 Display Pro works with CalMAN.

We don't currently have a client for the Mac, but we also haven't announced our computer calibration software based off CalMAN 5 yet either.

Gamut is the area encompassed by the primaries of the display, or the total amount of color a display can produce.

Something like my Dell 2408wfp has a very wide gamut:


The dots are where the colors actually measure, the squares are where they should be for sRGB or rec.709 content (HDTV and computer monitors share the same red green and blue colors). The position on this graph shows the hue and saturation of each color.

The LUT can correct the white point, which should also help correct the Cyan Magenta and Yellow colors to some degree. But in order to relocate the Red, Green and Blue you need to either have a CMS (Color management system) in the display or use software that can use the ICC profile to remap the colors correctly.

Gamut also has a luminance component, or how bright the color is. Our software also has charts to show if the colors brightness is correct or if they need to be corrected as well.



Probably the most useful tool for evaluating color performance is the Color Checker chart.

Here is a shot of the targets for the color checker, you can see how having a wide gamut causes all the colors to be wrong.

Actually, I do remember what "gamut" is. "Gamut" is the range of acceptable values of colors that a given device or medium can accept. I'm assuming (correct me if I'm wrong) that there will be no out of gamut colors when playing video discs because they would not or could not be included after the encoding process. I'm assuming that gamut correction might apply when color correcting material on a monitor that is going to be printed on paper, for example. Photoshop shows out of gamut colors as does Lightroom, for example. So I don't think gamut correction applies in my case.

BK

I was able to check the accuracy of the correction to some degree using the 709 bars in the Joe Kane bars and the r, g and b filters that come with the disc. The blue looks spot on, and the other two colors vary in their accuracy. Kane's literature says this is because of the limited accuracy of the decoder in the TV set. I wonder if gamut correction can fix decoder errors as well?

But honestly, I'm very pleased with the results with this corrected Sony monitor. I don't know how much better this set can look, it already looks pretty impressive to me, from deepest blacks to brightest whites, and flesh tones and other colors look real good. I know it's not an XBR or a Pioneer Elite, but we're talking about refinements on top of refinements at this stage of the game.

BK

And Joel proved me wrong... it has to do with the accuracy of reproducing specific colors within the monitor itself. When the i1 Profiler is doing its job, it compares the colors of about a hundred Pantone swatches against its standard for those colors. It then produces the profile. Does this profile then correct the "out of gamut" nature of the monitor for those specific Pantone colors? Is this then different from what is entered into the LUT using the method that I've outlined? It seems to me that a non-linear screen would be corrected by the shape of the transfer curve in the lookup table, as long as a transfer curve shape can follow the trend of the gamut errors in any portion of the quadrant. This is not the same as remapping, but it looks like correction to a large degree to me. I assume you saw the LUT image of a fake profile that I produced by measuring the screen when set to "vivid" in a previous post. The curve is quite curvy so it looks like some degree of gamut correction as long (as there are linear errors for each gun) could be possible in the LUT???? I agree that if the gamut is scattered, it's tough to fix with a simple curve. But I'm an audio man by profession and there are things I don't know about video so I'm here to learn.
Edited by bobkatz - 2/27/13 at 7:18am

Perhaps Calman was not able to do this back at the time I bought my i1 Display pro, but I would have bought the product at that time But at the time I believe I did check If I had known this when I bought my i1Display. Your literature says "OEM i1 Display" on this page: http://store.spectracal.com/calman5/licenses. Was it always able to work with an OEM i1Display pro? I don't recall seeing this back a few years ago, but I could be wrong.

It would have been wonderful to work with Calman and my home theatre at the time I was using a standalone blu-ray player. But now I'm using it all in the HTPC and I have a LUT correction.

How much time is involved in using Calman with a test disc to set up the monitor's r g b and rgb bias and brightness/contrast to linearize the display? Would (could) this look better than the method that I've used with i1Display and the LUT?

I assume that you can't really correct out-of-gamut this way, either, that you really need a monitor profile.
Edited by bobkatz - 2/27/13 at 7:17am

I believe JRiver uses madVR (a term that I'm just getting familiar with) in its "Red October HQ" video rendering engine. If you get any success with Upsilon Mixer, please let us know.


BK

Of course it applies. The disk encodes content into YCrCb and when decoded should produce an XYZ value from the display. That only works correctly if your display has exactly the correct Red Green and Blue, if your gamut is slightly off colors will get pulled and pushed away from their targets. Look at my gamuts above. None of the colors are a correct, but the gamut of the monitor fully encompasses the target gamut for rec.709.


Here is the long list of hardware supported:
http://store.spectracal.com/support/hardware-support.html

We did not launch with support for the retail meter, but I believe it was added within about 6 months.


There is some variability in setting up the monitor based on the skill of the user, but typically it that should be around 5-10 minutes, then setting up the LUT runs an automated correction process that takes 5 minutes tops.

So the PC client is not a stand alone application and requires Calman?

Correct, the client piece is a tray app responsible for persisting the LUT, ICC, and DDC settings as well as generating patterns.

CalMAN (or CalPC) is the piece that talks to the meter to gather the data and perform the corrections.