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GCD - Gamut Calibration Disk - Page 7

Poll Results: What format would you prefer for the HTPC?

 
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32 Total Votes  
post #181 of 608
5/18/12 at 12:28pm
Thread Starter 
The colour test patterns are not in any particular saturation or luminance. It's purely a test pattern with known xyY values used to determine a displays quality based on your numbers you have done a great job. The dE values for the test colours should be rated higher then the dE for rgbcym since they represent mixed colours and not only pure colours.
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post #182 of 608
5/18/12 at 12:34pm
I use them to compare best variation my calibrate?
1) 75L/100S
2) 75L/75S
3) 100L/75S
4) 100L/100S

or not?
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post #183 of 608
5/18/12 at 12:42pm
Thread Starter 
Any. When you calibrate to 100/75, 75/75, 75/100 or 100/100 all you try to is to get your display any given colour at any given saturation/ luminance. The test pallet will tell you how you have done. If you have higher dE then you did, then you should calibrate at a different saturation or luminance.
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post #184 of 608
5/18/12 at 12:43pm
Thread Starter 
Sorry just read what you said. Yes that is correct
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post #185 of 608
5/18/12 at 12:49pm
best - minimum average dE colour test pattern ?

Or must measure:
100L,100S
100L,75S
100L,50S
75L,100S
75L,75S
75L,50S
50L,100S
50L,75S
50L,50S

And average dE?

Or colour test pattern replaces this?

Then the calibration is much easier!
If so it is wonderful news!
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post #186 of 608
5/18/12 at 12:52pm
Thread Starter 
You calibrate to the saturation/luminance that give you the best result (based on average) dE). When that is done you you can check how you have done with the test colours.

If your display preform correct then you should see the lowest dE for the test patterns when you calibrate the patterns (rgbcym) that give you the lowest dE.
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post #187 of 608
5/18/12 at 1:39pm
That is colour test pattern correlated with average all saturation/luminance?
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post #188 of 608
5/18/12 at 1:55pm
What is better?
Gamma 2.2 and greyscale dE 1-3 (average 1.5) or
Gamma 2.0 and greyscale dE 0-1 (average 0.5)?
My TV LED Samsung UE55B7000.

My eyes are satisfied briightness 40-50 ftl.
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post #189 of 608
5/18/12 at 1:59pm
Quote:
Originally Posted by anta1974 View Post

Zoyd!
Use your Color Checker Palette.
Calibrate 75 sat\\75 luma
My Result:
ΔE94
1.72
0.58
1.17
1.95
1.76
0.87
0.90
1.99
1.19
0.99
0.81
0.84
Good or bad?

YourColor Checker Palette use 100% luma or 75% luma?
If 100% luma - then it can not be used to assess the quality of calibration
To assess patterns of a real, need to be all in table:

100L,100S
100L,75S
100L,50S
75L,100S
75L,75S
75L,50S
50L,100S
50L,75S
50L,50S
???

 

That's a very good result (avg = 1.23). The color checker patterns are "real world" colors, ones that have been determined to be important to get right and used as a color grading metric. They cover a luma range of 34% to 69%.


Here is the best I could do on my display:

All values are dE94
 

  No CMS 100L/100S 75L/100S 75L/75S Skin Tone Tweak
dark skin 2.10 1.21 0.86 0.85 0.62
light skin 3.22 3.78 2.88 2.36 0.93
blue sky 2.99 0.82 1.00 1.04 0.72
foliage 2.12 2.53 1.86 0.97 0.96
blue flower 2.12 2.07 1.60 1.23 1.20
bluish green 3.93 2.87 1.02 1.03 0.73
orange 4.00 2.20 1.51 1.62 2.07
purplish blue 3.27 0.92 1.06 0.61 0.71
moderate red 4.68 2.47 1.25 1.41 2.18
purple 2.24 1.61 1.06 1.09 0.92
yellow green 2.41 1.61 0.90 0.54 0.60
orange yellow 2.48 1.45 1.17 0.82 1.22
Average 2.96 1.96 1.35 1.13 1.07
Stdev 0.87 0.86 0.57 0.49 0.53
min 2.10 0.82 0.86 0.54 0.60
max 4.68 3.78 2.88 2.36 2.18

The last column was obtained by desaturating red a small amount to get skin tones to line up at the expense of orange and moderate red.

This is not a free lunch! If we look at what happens at the extremes of the gamut (100L/100S) we get this:
 

R 3.64
G 2.62
B 1.61
Y 0.38
C 2.39
M 2.63
average 2.21
stdev 1.11
min 0.38
max 3.64

That's the best you can do (on this display) without an outboard 3D LUT and it's a good trade to make in my opinion, the frequency of occurrence of images with maximum saturation and luminance is much lower than the color checker colors.

I'm satisfied now that I have squeezed every last photon of adjustment out of this display...beertime!


Edited by zoyd - 6/6/12 at 3:39am
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post #190 of 608
5/18/12 at 2:12pm
Thank you very match, Zoyd!
Where your result 75S/100L?
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post #191 of 608
5/18/12 at 2:24pm
Quote:
Originally Posted by anta1974 View Post

Where your result 75S/100L?

I didn't do it because I was able to find a solution following the progression at 75L. 100L is probably not a very useful point to check, the average luminance of the colors is 52.4% for gamma=2.2
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post #192 of 608
5/18/12 at 5:11pm
Quote:
Originally Posted by anta1974 View Post

What is better?
Gamma 2.2 and greyscale dE 1-3 (average 1.5) or
Gamma 2.0 and greyscale dE 0-1 (average 0.5)?
My TV LED Samsung UE55B7000.

My eyes are satisfied икшпретуіі 40-50 ftl.

brightness = яркости? I wondered where you were from.

I think gamma=2.2 would be better.
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post #193 of 608
5/19/12 at 5:06am
Thread Starter 
I had a go today and this is the best I can come up with:
not brilliant but ok since my TV is undersaturted for red, yellow and green.
Measured x y Y [%] Y [cd/m2] ΔL ΔC ΔH ΔE94
dark skin 0.388 0.352 10.28% 9.7 -0.50 2.60 1.05 1.70
light skin 0.383 0.354 35.81% 33.9 -0.75 1.41 1.11 1.30
blue sky 0.249 0.270 18.93% 17.9 -0.41 0.92 0.73 0.83
foliage 0.331 0.413 13.24% 12.5 -0.05 4.18 1.87 2.32
blue flower 0.272 0.255 23.55% 22.3 -0.23 0.29 1.21 0.90
bluish green 0.256 0.354 41.90% 39.7 -0.02 0.42 0.66 0.47
orange 0.479 0.401 33.86% 32.1 -2.88 9.50 1.56 3.84
purplish blue 0.215 0.190 12.56% 11.9 -1.57 3.06 0.30 1.85
moderate red 0.449 0.313 21.04% 19.9 -2.27 4.46 0.75 2.69
purple 0.299 0.229 6.82% 6.5 -0.93 2.58 0.47 1.43
yellow green 0.366 0.470 44.96% 42.6 -0.40 10.47 1.29 2.78
orange yellow 0.453 0.433 45.74% 43.3 -2.08 10.00 1.06 3.24
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post #194 of 608
5/19/12 at 8:57am
1) why not calibrate 50 sat/75 luma
2) why CALMAN recomendation:
50-60 ftl - gamma 2.0
40-50 ftl - gamma 2.2
30-40 ftl - gamma 2.4
3) where more shadow detail - gamma 2.0 or gamma 2.2?
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post #195 of 608
5/20/12 at 5:05am
Quote:
Originally Posted by anta1974 View Post

1) why not calibrate 50 sat/75 luma
2) why CALMAN recomendation:
50-60 ftl - gamma 2.0
40-50 ftl - gamma 2.2
30-40 ftl - gamma 2.0
3) where more shadow detail - gamma 2.0 or gamma 2.2?

1 - no improvement for me but you can try.
2 - ask calman support, those are general guidelines (don't know why they would recommend 2.0 @30-40 though).
3 - generally 2.2 is better, 2.0 tends to wash out lower levels. Use your eyes to determine what looks best in your viewing environment.
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post #196 of 608
5/20/12 at 5:07am
Quote:
Originally Posted by visca blaugrana View Post

I had a go today and this is the best I can come up with:
not brilliant but ok since my TV is undersaturted for red, yellow and green.

Did you use a flat or measured gamma response?
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post #197 of 608
5/20/12 at 5:33am
Excuse me.
Of course, 30-40 ftl - gamma 2.4!
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post #198 of 608
5/21/12 at 8:47am
Used the disc for calibration today, picture definitely improved when compared to my previous process using AVS disk, windows for grey scale and gamma, and large APL windows for primary and secondary.
Seem to still have an issue with Magenta at 25% saturation tho and black level at IRE 0 has doubled from 0.012. Red saturation not great either, however if i push it further faces become way too red, seem to have a nice balance.

Great work!

Attached is my HCFR file.

 

Calibration 21st May using Viscas AV Forums disc, APL with coloured level backgrounds.zip 5.6796875k . file
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post #199 of 608
5/21/12 at 12:59pm
Quote:
Originally Posted by zoyd View Post

That's a very good result (avg = 1.23). The color checker patterns are "real world" colors, ones that have been determined to be important to get right and used as a color grading metric. They cover a luma range of 34% to 69%.


Here is the best I could do on my display:

All values are dE94

No CMS 100L/100S 75L/100S 75L/75S Skin Tone Tweak
dark skin 2.10 1.21 0.86 0.85 0.62
light skin 3.22 3.78 2.88 2.36 0.93
blue sky 2.99 0.82 1.00 1.04 0.72
foliage 2.12 2.53 1.86 0.97 0.96
blue flower 2.12 2.07 1.60 1.23 1.20
bluish green 3.93 2.87 1.02 1.03 0.73
orange 4.00 2.20 1.51 1.62 2.07
purplish blue 3.27 0.92 1.06 0.61 0.71
moderate red 4.68 2.47 1.25 1.41 2.18
purple 2.24 1.61 1.06 1.09 0.92
yellow green 2.41 1.61 0.90 0.54 0.60
orange yellow 2.48 1.45 1.17 0.82 1.22
Average 2.96 1.96 1.35 1.13 1.07
Stdev 0.87 0.86 0.57 0.49 0.53
min 2.10 0.82 0.86 0.54 0.60
max 4.68 3.78 2.88 2.36 2.18

The last column was obtained by desaturating red a small amount to get skin tones to line up at the expense of orange and moderate red.

This is not a free lunch! If we look at what happens at the extremes of the gamut (100L/100S) we get this:

R 3.64
G 2.62
B 1.61
Y 0.38
C 2.39
M 2.63
average 2.21
stdev 1.11
min 0.38
max 3.64

That's the best you can do (on this display) without an outboard 3D LUT and it's a good trade to make in my opinion, the frequency of occurrence of images with maximum saturation and luminance is much lower than the color checker colors.

I'm satisfied now that I have squeezed every last photon of adjustment out of this display...beertime!

Do you have a disc and known reference xyY values for all these other colors?
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post #200 of 608
5/21/12 at 1:07pm
Thread Starter 
See first post that include both disk and targets
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post #201 of 608
5/23/12 at 10:46am
Zoyd!
Сan change in table dE94 in the dE2000?
End average dE and amount dE.

Please.

Today I tried to calibrate the 50 sat/ 75 luma - the result is worse!
The total delta of color checker - 19.19 against 14.76 ( 75 sat/75 luma).

75 luma/100sat - 23.66.

I still need to try skin tone tweak.

What is stdev?
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post #202 of 608
5/23/12 at 3:52pm
Quote:
Originally Posted by anta1974 View Post
Zoyd!
Сan change in table dE94 in the dE2000?
End average dE and amount dE.

Please.

Today I tried to calibrate the 50 sat/ 75 luma - the result is worse!
The total delta of color checker - 19.19 against 14.76 ( 75 sat/75 luma).

75 luma/100sat - 23.66.

I still need to try skin tone tweak.

What is stdev?
dE2000 is not going to tell you anything new compared to dE94 but I included it anyway. stdev=standard deviation, the smaller that is the smaller the spread in errors. Total dE is not useful, you need to look at min/max and average, I put those in too along with a plot of lightness/chromaticity/hue errors so you can see which color has which problem. I also unlocked the color and gamma target pages so you can add your own plots and statistics if you'd like.

 

GCD_targets v8.xlsx.zip 147.7236328125k . file
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post #203 of 608
5/23/12 at 5:39pm
Quote:
Originally Posted by visca blaugrana View Post

See first post that include both disk and targets

Ah! Thanks.
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post #204 of 608
5/24/12 at 7:35am
Quote:
Originally Posted by zoyd View Post

dE2000 is not going to tell you anything new compared to dE94 but I included it anyway. stdev=standard deviation, the smaller that is the smaller the spread in errors. Total dE is not useful, you need to look at min/max and average, I put those in too along with a plot of lightness/chromaticity/hue errors so you can see which color has which problem. I also unlocked the color and gamma target pages so you can add your own plots and statistics if you'd like.

Thank you very match!!!
dE2000 and dE94 - different result.
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post #205 of 608
5/24/12 at 7:40am
How to calculate standard deviation?
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post #206 of 608
5/24/12 at 3:14pm
in excel it's stdev(cell range)
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post #207 of 608
5/25/12 at 1:59am
Is not it better to calibrate the 70sat/70luma?

nearer 50%
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post #208 of 608
5/25/12 at 2:27am
75%luma is closer to 50%luminance for gamma=2.2 Anyway, given probe inaccuracies and other factors once you've gotten average and max dE below 3 you are done, further tinkering is just a numerical exercise.
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post #209 of 608
5/25/12 at 2:33am
Thank you!
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post #210 of 608
5/25/12 at 2:33am
max dE below 3 - what dE (1976 or 1994 or 2000)?
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