MadVR - ArgyllCMS - Page 2 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 492Likes
Reply
 
Thread Tools
post #31 of 4618 Old 05-07-2013, 10:07 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
I have also tried with BT.1886 but it looks like something is wrong.

I used
Code:
dispcal.exe -d 1 -v -m -q h -y 6 -w 0.312713,0.329016 -G 2.4 -f 0 -o madVR_C.icm SAM
targen.exe -v -d 3 -G -s 20 -g 100 -f 2000 -c madVR_C.icm SAM
dispread.exe -v -d 1 -y 6 -k SAM.cal SAM
colprof.exe -v -a X -q h -b h SAM
collink.exe -v -3 m  -q h  -e t  -E t  -I b  -I2.2  -G  -a SAM.cal  -i al  Rec709.icm SAM.icm SAM_HD.icm















Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
Sponsored Links
Advertisement
 
post #32 of 4618 Old 05-07-2013, 04:38 PM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by MSL_DK View Post

I have also tried with BT.1886 but it looks like something is wrong.

It's impossible to help or make suggestions without any description or explanation of what you think is wrong....
gwgill is offline  
post #33 of 4618 Old 05-08-2013, 04:03 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Quote:
Originally Posted by gwgill View Post

It's impossible to help or make suggestions without any description or explanation of what you think is wrong....

My mistake. It is not related to BT.1886. I'll show some screenshots of some test pattern showing the problem later today.

I have a questions about the backlight on a SAMSUNG LED display screen. What influence do backlight on gamma and white balance when taking measurements in ArgyllCMS and the final outcome? Should backlight be turned off?

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
 
post #34 of 4618 Old 05-08-2013, 05:46 AM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by MSL_DK View Post

I have a questions about the backlight on a SAMSUNG LED display screen. What influence do backlight on gamma and white balance when taking measurements in ArgyllCMS and the final outcome? Should backlight be turned off?

I guess I'm not understanding you. I'm not aware that Samsung make an LED screen. I think that Sony has some a rather expensive one, and that's about it if you don't count hand held AMOLED devices.

Perhaps you mean an LCD screen with LED backlight ?

Typically LCD screens will be unusable without a backlight to provide the light that the LCD panel filters. In fact, I'm surprised to hear that any such display has an option to turn it off, since the display will be completely black and useless without it.
gwgill is offline  
post #35 of 4618 Old 05-08-2013, 06:03 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Quote:
Originally Posted by gwgill View Post

Perhaps you mean an LCD screen with LED backlight ?.

Yeah
Quote:
Originally Posted by gwgill View Post

Typically LCD screens will be unusable without a backlight to provide the light that the LCD panel filters. In fact, I'm surprised to hear that any such display has an option to turn it off, since the display will be completely black and useless without it.

No ... however backlight = 0

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #36 of 4618 Old 05-08-2013, 08:11 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Quote:
Originally Posted by MSL_DK View Post

My mistake. It is not related to BT.1886. I'll show some screenshots of some test pattern showing the problem later today.

I have a questions about the backlight on a SAMSUNG LED display screen. What influence do backlight on gamma and white balance when taking measurements in ArgyllCMS and the final outcome? Should backlight be turned off?

Here you go ... I followed the guide to the letter ...

EDIT: And yes, ran "dispwin-c" in case.







dispcalGUI1.zip 7k .zip file

EDIT:

yCMS

Attached Files
File Type: zip dispcalGUI1.zip (7.2 KB, 463 views)

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #37 of 4618 Old 05-08-2013, 08:16 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Quote:
Originally Posted by MSL_DK View Post

I have a questions about the backlight on a SAMSUNG LED display screen. What influence do backlight on gamma and white balance when taking measurements in ArgyllCMS and the final outcome? Should backlight be turned off?

I find that the backlight affects gamma. I set it to 0 do I get gamma 2.2. I set the backlight to 8 do I get gamma 1.9 HCFR before ArgyllCMS 2.2

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #38 of 4618 Old 05-08-2013, 11:36 AM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by VerGreeneyes View Post

This is interesting stuff smile.gif I've yet to try the actual 3DLUT creation, but I had some questions.
Why do this? The interactive adjustment just lets you set your monitor's white point and brightness so that they're closer to the desired one (assuming your monitor has the necessary controls).
I should have added in my first post the scope for the workflow is directed at a calibration for televisions. Most televisions do not have controls similar to the controls for RGB on a computer monitor.
Quote:
Second, I don't just want madVR to use my hard won calibration and profile, so I definitely want to have the calibration enabled outside madVR and the profile installed (e.g. for use in Firefox). Does this mean I should follow suggestion 3 from the Notes section of post 2? Or will the installed profile still get applied in madVR (I would expect it to be overridden by the 3DLUT)? Do I lose any quality by doing this?
Yes, you would use option #3 and uncheck 'disable GPU gamma ramps' in MadVR (for sanity)
Quote:
Finally, isn't setting the chromaticity coordinates for the whitepoint to 0.312713 and 0.329016 the same as selecting a color temperature of 6500 K with a Daylight reference? I would expect the ideal white point to correspond with sRGB, which Rec. 709 uses, and that assumes D65 IIRC.

Right, should be the same.

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #39 of 4618 Old 05-08-2013, 12:48 PM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
@Graeme

Can you provide the formula ArgyllCMS uses to calculate the gamma targets when "-Ib -I2.2" parameters are used with collink.exe? Does it use the measured white/black levels?

The reason I'm asking is so that I can verify the results by inputting the target values into Calman and then taking measurements with it.

Thanks smile.gif

EDIT: It seems the BT.1886 formula calls for the use of the exact exponent of 2.4. (ITU ref doc)

Joel Barsotti said the exponent of 2.4 is an integral part of the BT.1886 formula. (link)

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #40 of 4618 Old 05-08-2013, 03:36 PM
Member
 
cfelicio's Avatar
 
Join Date: Jul 2011
Posts: 123
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 17
What is the performance impact of using this in a lower tier HTPC (in my case: Trinity A6-5400k)? Will it be playable or it will eat too much GPU?
cfelicio is offline  
post #41 of 4618 Old 05-08-2013, 04:53 PM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by N3W813 View Post

@Graeme

Can you provide the formula ArgyllCMS uses to calculate the gamma targets when "-Ib -I2.2" parameters are used with collink.exe? Does it use the measured white/black levels?
It's in the source code if you want to check the details. http://www.argyllcms.com/Argyll_dev_src.zip in link/collink.c.

The current code as of this instant:

Looks up the black point of the display in relative XYZ (ie. Y = 1 at white)

Invert it through the source profile matrix (ie. convert it to linear light Rec709
RGB space for Rec709.icm source).

Compute an "average" input offset value so as to maintain strict neutrality of the source colors:

LB = 0.2126 * Rb + 0.7152 * Gb + 0.0722 * Bb
LW = 1

Compute the RGB offset and scaling factors (ie. using the BT1886 formula):

γ = 2.4 for strict BT.1886, other values for other viewing conditions

a = ((LW^1/γ - LB^1/γ)^γ

b = LB^1/γ / (LW^1/γ - LB^1/γ)
Quote:
It seems the BT.1886 formula calls for the use of the exact exponent of 2.4. (ITU ref doc)
Correct, and that's what it defaults to (although I have my reservations about its real world usability).
Quote:
Joel Barsotti said the exponent of 2.4 is an integral part of the BT.1886 formula. (link)
That link just reaches a login page, so I'm not sure exactly what he said. It's "integral" in that it's part of the recommendation. But it's just a number, and can therefore be changed, and the particular number chosen is very much a result of the expected viewing conditions. See Poynton for all the details discussions of how the historic gamma numbers developed.

BT.1886 is just an input offset black matching scheme with a curve shape that is a pure 2.4 power.
ArgyllCMS dispcal had that capability before BT.1886 was invented, including being able to set whatever power you want. So it's nothing technically special.
gwgill is offline  
post #42 of 4618 Old 05-08-2013, 05:47 PM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by cfelicio View Post

What is the performance impact of using this in a lower tier HTPC (in my case: Trinity A6-5400k)? Will it be playable or it will eat too much GPU?

You will need to try it. If you video starts to stutter or skip after you enable the 3DLUT then you'll know it's not sufficient.

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #43 of 4618 Old 05-09-2013, 01:36 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Quote:
Originally Posted by MSL_DK View Post

Here you go ... I followed the guide to the letter ...

EDIT: And yes, ran "dispwin-c" in case.







dispcalGUI1.zip 7k .zip file

EDIT:

yCMS


I experience a yellowish tinge? Do you not?

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #44 of 4618 Old 05-09-2013, 02:47 AM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,275
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 1316 Post(s)
Liked: 1064
Quote:
Originally Posted by gwgill View Post

Looks up the black point of the display in relative XYZ (ie. Y = 1 at white)

I haven't checked but are you sure scaled values give you the proper curvature? BT.1886 formally uses absolute luminance.
zoyd is offline  
post #45 of 4618 Old 05-09-2013, 04:32 AM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by zoyd View Post

I haven't checked but are you sure scaled values give you the proper curvature? BT.1886 formally uses absolute luminance.

Lw is just a scale factor. Divide it by Lw and it's all the same.

x^y = (s.x)^y / s^y

They use absolute because it makes the spec simpler - normalizing the brightness to 1 would just complicate the definition for no change in the result.
gwgill is offline  
post #46 of 4618 Old 05-09-2013, 04:44 AM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,275
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 1316 Post(s)
Liked: 1064
zoyd is offline  
post #47 of 4618 Old 05-09-2013, 06:59 AM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by zoyd View Post

But black does not scale with peak white so the function has to be explicitly dependent on absolute values (I think)

Black is absolute in BT.1886, just like white, so if you scale white to 1, you have to scale black by the same amount, and the resulting offset & scale numbers come out of BT.1886 exactly the same.
gwgill is offline  
post #48 of 4618 Old 05-09-2013, 07:23 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
Okay ... this is weird! As I said, I tried with dispwin -c but just tried with
Quote:
2) Don't use the collink "-a display.cal" parameter (ie. create a link/3dlut that doesn't
incorporate the display calibration curves), and load the calibration curves into the VideoLUT
using "dispwin display.cal"

This gives me a completely different result, but I also need to uncheck "disable GPU gamma ramps"

Something is wrong with madVR

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #49 of 4618 Old 05-09-2013, 10:06 AM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
@Graeme
RE: Results of using “Black point compensation” in DispcalGUI profiling (step B.10)

From your discussion with cyberbeing in the MadVR thread over at Doom9, you stated that the ‘Black point compensation’ (BPC) option in DispcalGUI is an option you “can’t ever imagine using.” But from my calprofs last night on my Sharp LE640 TV (16-235 only, -E switch used for both dispcal and dispread), the black level is raised significantly without the BPC option enabled. Viewing a black clipping pattern (flashing steps from 2-25) with BPC disabled, black is shown at bar 11 instead of 16.

Readings of reference video black 16
Before cal/profile – 0.016 fL
With 3DLUT, BPC disabled – 0.032 fL
With 3DLUT, BPC enabled – 0.014 fL

I’ve attached the all files generated from ArgyllCMS/DispcalGUI from this particular cal/prof. The DispcalGUI generated ti3 file with BPC is xxxxx.bpc.ti3.
Sharp.LE640.calprof.files.zip 773k .zip file
Attached Files
File Type: zip Sharp.LE640.calprof.files.zip (773.5 KB, 272 views)

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #50 of 4618 Old 05-09-2013, 12:04 PM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by zoyd View Post

I haven't checked but are you sure scaled values give you the proper curvature? BT.1886 formally uses absolute luminance.

@Graeme
In confirming with zoyd's suspicions, I also had a feeling either I was doing something wrong or the BT.1886 implemented in ArgyllCMS is not calculating correct targets because I resulted in incorrect BT.1886 gamma curves on both on my displays. Last night, I performed the following cal/prof test on my Sharp LE640 television.

1. TV was calibrated with ArgyllCMS to power gamma 2.2
2. Resulted cal was loaded into videoLUTs (readings below "Display with G2.2 videoLUT")
3. Profiled with massive testchart (2386 patterns)
4. Created 3DLUT with -Ib -I2.4, without -a
5. Made sure videoLUT still had the same values from step 2
6. Imported 3DLUT, unchecked "disable GPU gamma ramps"
7. Measured 11-step grayscale (readings below "Actual measured with 3DLUT")

In the chart below you can see results the power gamma 2.2 to display is calibrated to. There should be enough room for the 3DLUT to work with to transform to a BT.1886 2.4 gamma curve. I've also included calculated BT.1886 2.4 targets from the BT1886CalcV3.xls (attached) and from the SpectraCal Calman v5 calibration software. They basically have the same targets with negligible differences. On the other hand, the actual measured grayscale with the 3DLUT in MadVR is very different from these targets, especially from 10-60%.



BT1886CalcV3.zip 19k .zip file
Attached Files
File Type: zip BT1886CalcV3.zip (19.5 KB, 259 views)

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #51 of 4618 Old 05-09-2013, 05:32 PM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by N3W813 View Post

But from my calprofs last night on my Sharp LE640 TV the black level is raised significantly without the BPC option enabled.

I’ve attached the all files generated from ArgyllCMS/DispcalGUI from this particular cal/prof.

You haven't provided the device_link.icm or the command line used to create it (so I can re-created it), so it's a bit hard to comment.
gwgill is offline  
post #52 of 4618 Old 05-09-2013, 05:58 PM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by gwgill View Post

You haven't provided the device_link.icm or the command line used to create it (so I can re-created it), so it's a bit hard to comment.

Using your latest rec709.icm file in \ref
Command line is
Collink.exe -v -3m -qh -et -Et -Ib -I2.2 -G -ial Rec709.icm icm_in_zip.icm madvr.icm

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #53 of 4618 Old 05-09-2013, 07:27 PM
Member
 
cfelicio's Avatar
 
Join Date: Jul 2011
Posts: 123
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 17
Quote:
Originally Posted by N3W813 View Post

You will need to try it. If you video starts to stutter or skip after you enable the 3DLUT then you'll know it's not sufficient.

Ok, I gave it a try and with Smooth Motion enabled, it's borderline playable (drops a frame every couple of mins) on 720p scaled to 1080p. Adds 10-15ms to the render queue on my A6-5400k. The funny thing is, if I disable the Smooth Motion, then the processing time pretty much remains the same (with or without the 3dlut)....
cfelicio is offline  
post #54 of 4618 Old 05-09-2013, 09:30 PM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
Quote:
Originally Posted by N3W813 View Post


In the chart below you can see results the power gamma 2.2 to display is calibrated to. There should be enough room for the 3DLUT to work with to transform to a BT.1886 2.4 gamma curve. I've also included calculated BT.1886 2.4 targets from the BT1886CalcV3.xls (attached) and from the SpectraCal Calman v5 calibration software. They basically have the same targets with negligible differences. On the other hand, the actual measured grayscale with the 3DLUT in MadVR is very different from these targets, especially from 10-60%.

Looks exactly as expected if you used the "black point compensation" profile.

Since the BPC profile is lying to collink, collink thinks that the display has a zero black, and bt1886 reduces to a pure 2.4 power curve:

50% mark for 3dlut: log(21.45-.0486/110.89)/log(0.5) = 2.37, pretty close to 2.4

But I think there are a couple of basic problems with the whole idea of BT.1886 being used as per the spec. with profiles:

* Typical instruments struggle for accuracy in measuring displays with a very dark black point.
* For display with very dark blacks, the profile doesn't capture the black point accurately enough (it may be a small absolute error of 0.02 cd/m^2 which compared to white is 0.02%, but compared to the true black is a 50% error).
* BT.1886 effective gamma (the effect it has on the overall brightness of the image) is quite sensitive to the black point value.

So I think I will proceed with changing the defaults in collink to aim for an effective (default) gamma of 2.2 and make the gamma adjustment value also be effective gamma. That way the apparent brightness will not be sensitive to any issues with black point accuracy. I'll provide a different option to specify technical gamma for those who want to try pure BT.1886, etc..

The problem with "BPC off" I think is due to a mistake on my part - I was converting the display point to input space (Rec709) using a reverse lookup of the input profile that clipped to the input gamut, and if the display black point is not neutral (as is the case here), the clipping brightened up the black point a lot to get it in gamut.

I'll change the code somewhat to clip it in a different way, that doesn't brighten it up as much. If this still proves to be objectionable, then rather than try to correct the black point neutrality as much, I can try blending it to the true black point (but once again, inaccuracies in the readings and profile model near the black point can mess this up somewhat.)
gwgill is offline  
post #55 of 4618 Old 05-09-2013, 11:37 PM
Advanced Member
 
gwgill's Avatar
 
Join Date: Jan 2013
Location: Melbourne, Australia
Posts: 937
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 256 Post(s)
Liked: 192
I've updated http://www.argyllcms.com/Win32_collink_3dlut.zip with the latest fixes for BT.1886 processing. The black point shouldn't be lifted as much when the display black is not neutral, and the gamma curve is now effective gamma by default, making the reproduction much less dependent on the black point being measured or profiled with perfect accuracy. Note that the syntax has changed if you want to alter the default effective gamma, it now looks like "-I b:2.2". The default effective gamma is 2.2, since this is close to what you get with a power of 2.4 and and some sort of black point offset.
gwgill is offline  
post #56 of 4618 Old 05-10-2013, 07:48 AM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by gwgill View Post

I've updated http://www.argyllcms.com/Win32_collink_3dlut.zip with the latest fixes for BT.1886 processing. The black point shouldn't be lifted as much when the display black is not neutral, and the gamma curve is now effective gamma by default, making the reproduction much less dependent on the black point being measured or profiled with perfect accuracy. Note that the syntax has changed if you want to alter the default effective gamma, it now looks like "-I b:2.2". The default effective gamma is 2.2, since this is close to what you get with a power of 2.4 and and some sort of black point offset.

Thanks, I'll test my workflow with the updates.

FYI, the collink.exe in the \link folder is older than the one in \bin folder. I'm assuming I should be using the one in \bin, correct? wink.gif

EDIT
I just tested -Ib:2.2 through 2.4 and I'm getting really weird gamma curves. 2.2 target ending up closer to 2.6 avg gamma. I will do more testing and post the readings.

FYI, the option -IB:g.g is not working.
"Diagnostic: Intent modifier (-I) argument 'B:2.2' not recognised"

Without x.x
"Diagnostic: Intent modifier (-I) argument 'B' not recognised"

EDIT #2
Attached my device link icms
output.zip 3841k .zip file
Attached Files
File Type: zip output.zip (3.75 MB, 255 views)

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #57 of 4618 Old 05-10-2013, 09:44 AM
Member
 
MSL_DK's Avatar
 
Join Date: Nov 2011
Location: Denmark
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 11
@Graeme
Please look here ... Is there an error with collink or madVR, or misunderstand I the use of collink, madVR GPU gamma ramps and dispwin?

collink "-a display.cal" and running dispwin -c (ON: fullscreen exclusive and "GPU gamma ramps")


collink without "-a display.cal" and with dispwin "display.cal" (ON: "fullscreen exclusive" OFF "GPU gamma ramps")

Panasonic TX-55CX700E - Dynaudio Focus 200 XD
MSL_DK is offline  
post #58 of 4618 Old 05-10-2013, 10:51 AM
Member
 
fallengt's Avatar
 
Join Date: Jul 2009
Posts: 162
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 10
Quote:
Originally Posted by N3W813 View Post

Thanks, I'll test my workflow with the updates.

FYI, the collink.exe in the \link folder is older than the one in \bin folder. I'm assuming I should be using the one in \bin, correct? wink.gif

EDIT
I just tested -Ib:2.2 through 2.4 and I'm getting really weird gamma curves. 2.2 target ending up closer to 2.6 avg gamma. I will do more testing and post the readings.

FYI, the option -IB:g.g is not working.
"Diagnostic: Intent modifier (-I) argument 'B:2.2' not recognised"

Without x.x
"Diagnostic: Intent modifier (-I) argument 'B' not recognised"

EDIT #2
Attached my device link icms
output.zip 3841k .zip file

It's -i[space]b:g.g not -ib:g.g

It gota average 2.4 gamma curve using -i b:2.2.which is too dark for me.
fallengt is offline  
post #59 of 4618 Old 05-10-2013, 11:26 AM - Thread Starter
AVS Forum Special Member
 
N3W813's Avatar
 
Join Date: Feb 2003
Posts: 1,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked: 79
Quote:
Originally Posted by fallengt View Post

It's -i[space]b:g.g not -ib:g.g

It gota average 2.4 gamma curve using -i b:2.2.which is too dark for me.

The space does not make a difference. wink.gif

In the documentation, there is -Ib and -IB. The capital 'B' specifies a technical BT.1886 gamma. smile.gif

My ArgyllCMS/MadVR 3DLUT Creation Workflow
My Sharp Elite Movie THX AV Mode Settings
--Aug 2011 Set, 2.2 gamma [ link ]
--Nov 2012 Set, 2.2 gamma [ link ]
N3W813 is offline  
post #60 of 4618 Old 05-10-2013, 01:32 PM
Member
 
fallengt's Avatar
 
Join Date: Jul 2009
Posts: 162
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 10
Really? Why I don't see the -IB syntax anywhere?



Did you copy collink.exe from /bin ?
fallengt is offline  
Sponsored Links
Advertisement
 
Reply Display Calibration

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off