New project: camera color profile calculation

DawMatt

Re: New project: camera color profile calculation

« Reply #180 on: 31 / May / 2008, 00:10:21 »

Advertisements

Quote from: lukg on 30 / May / 2008, 06:53:09

Ok!!! I really appreciated the work you're doing!

No problems.

Quote from: lukg on 30 / May / 2008, 06:53:09

EDIT: I've just downloaded my palette pics from zshare...and winrar opens it with no problem! Should I use some particular settings to make it compatible with 7zip?

I shouldn't think so. But for whatever reason the command line version of 7zip didn't recognise the files as archives, even the one you've just posted then.
EDIT: Any chance you could try zipping (rather than rarring) the files then reupload them?

Quote from: lukg on 30 / May / 2008, 06:53:09

EDIT2: ...i did a try to calibrate by myself using my palette, but with no success! I took many palette pics with still no success! (best gamut error about 42%). Can I ask you what are the reasons for setting zoom to middle and focus to infinity? Is it just to smooth and have homogeneous colors?

Thanks for giving the instructions a try!

I had similar issues originally. There are probably more secrets to taking a good palette shot but I've only figured out some of them. Just keep trying.

I'm not 100% sure about the reason for the zoom position, but I wouldn't be surprised if its related to lens distortion/chromatic aberrations/vignetting. These issues tend to be most prevalent at one end of the lens focal length or the other, typically at the wide end, and could impact the quality of the matrix generated. So the mid range zoom request seems a logical way to minimise these issues.

Pretty sure the focus to infinity requirement is to blur the colors rather than have sharp pictures of each of the liquid crystals/phosphor dots.

Logged

DawMatt

Re: New project: camera color profile calculation

« Reply #181 on: 31 / May / 2008, 00:26:48 »

Quote from: lukg on 30 / May / 2008, 13:45:37

This the only palette I get some success with! I had to deselect the black and dark grey patches (used 22 patches) to get an acceptable gamut error, and also I had to set im. bright. to 0.5.

OK, that's great that you've managed to get a calibration shot to work! It took days for me to finally get one to work properly.

Now that you have this working with im. bright at 0.5, you might want to try again with im. bright closer to 1.0. Maybe 0.75? I have found that a low im. bright value often gets you past the first hurdle (stage 1) but can increase the error rate across the zones in the final matrix. If you increase the im. bright value, while still keeping it low enough to complete stage 1, you might find better error rates across each of the zones used.

Quote from: lukg on 30 / May / 2008, 13:45:37

But I have not understood how to use this matrix now without compile dng4ps
Hope someone could take a better palette than mines (i took many)

Camera -> XYZ matrix:
3,679790 1,286464 1,690627
1,145118 3,685682 0,174926
0,245843 -1,636507 11,881179
XYZ -> Camera matrix:
0,314732 -0,128898 -0,042887
-0,096843 0,309220 0,009228
-0,019851 0,045259 0,086325

zSHARE - s5palette.rar

I'll look into adding the matrix to my copy of the code.

Did you keep the "progress and results" log output for the color matrix? I'd like to know what the error rate was across each fo the zones, and if any areas were marked as bad during the calculation process.

Quote from: lukg on 30 / May / 2008, 13:45:37

EDIT: ok, i found "dngsetmatrix" instructions...with this matrix I get some good results:
If someone wants to try (you need dngsetmatrix.exe in the same directory) I wrote a simple batch file, just to avoid to rewrite the matrix everytime:

Quote
@echo off
dngsetmatrix.exe %1 M2 0.314732 -0.128898 -0.042887 -0.096843 0.309220 0.009228 -0.019851 0.045259 0.086325
pause

Just save it as "blabla.bat", move dng files over it to apply the new matrix.
For what I saw it seems better than DNG4PS matrix (S5 and also a720).

Does that mean the (potential) matrix verification steps in the wiki worked for you? I wrote them up but they didn't seem to work when I tested them.

I noticed your script applies the results to the second color matrix (M2). I had expected you would overwrite the first color matrix (M1) instead, or possibly even both matricies. Or maybe during your testing you overwrote both so your photo looks OK regardless? I only mention this because others might not be testing the matrix they think they are testing.

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #182 on: 31 / May / 2008, 08:05:08 »

ok, I'm going to take some better palette pics (i hope) before uploading it again!
My question about the zoom was about the problem of taking pics at middle zoom with a S5 with 12x.
As I remember I got many BAD areas.
About dngsetmatrix batch I forgot to change it, because I was experimenting with it since it's used M2 even in the instructions I followed. (I wrote both fields in my experiment....do you think it's better to write both M1 and M2 with same values?)
I'm going to upload conversion logs for different im. brightness so you can take a look at them.

« Last Edit: 31 / May / 2008, 13:57:45 by lukg »

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #183 on: 31 / May / 2008, 09:12:55 »

I don't know if it's normal, but this are my results changing only the im.brightness:

Brightness 1.00: BEST RESULTS FROM G=1,96000, min(E)=20,4% BAD <----- ONLY 20.4

?!?
Brightness 0.85: BEST RESULTS FROM G=2,02000, min(E)=38,4% BAD
Brightness 0.75: BEST RESULTS FROM G=2,04000, min(E)=35,4% BAD
Brightness 0.65: BEST RESULTS FROM G=1,84000, min(E)=21,4% BAD
Brightness 0.63: BEST RESULTS FROM G=1,84000, min(E)=21,3% BAD
Brightness 0.62: G=1,40328, range(E)=13,4%->13,4%, aver(E)=10,1% POOR RESULTS
Brightness 0.61: G=1,42006, range(E)=11,3%->11,3%, aver(E)=8,4% POOR RESULTS
Brightness 0.60: G=1,45888, range(E)=7,6%->7,6%, aver(E)=6,8%
Brightness 0.59: G=1,48614, range(E)=7,1%->7,1%, aver(E)=6,2%
Brightness 0.58: G=1,53668, range(E)=5,6%->5,6%, aver(E)=5,2%
Brightness 0.55: G=1,53812, range(E)=5,6%->5,6%, aver(E)=5,2%
Brightness 0.50: G=1,61465, range(E)=4,1%->4,1%, aver(E)=4,0%

Since the first error value (im. bright. 1.00) made me thinking, I tried with im. brightness values over 1.00, but with an error never less 20%.

Here are the logs:
zSHARE - logs.zip

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #184 on: 31 / May / 2008, 11:13:50 »

I did some tests using two different matrix. Indeed, as Dawmatt said, I get better results using the matrix with a little higher error.

Here are some examples:

(the pics are in order:
top-left= A720matrix
top-right= matrix obtained from my palette with 0.60 image brightness
bottom-left= camera jpg
bottom-right= matrix obtained from my palette with 0.50 image brightness
)

http://img92.imageshack.us/img92/861/catturadx5.jpg

http://img92.imageshack.us/img92/3770/catturakb1.jpg

http://img92.imageshack.us/img92/9393/catturalt8.jpg

I think the top-right pictures give, in overall, better results (more fidelity with the jpg camera). Except for the green color that doesn't match at all in all matrix.

These are only basic tests, since I get many bad errors and area no. doesn't match. during calculation.

« Last Edit: 31 / May / 2008, 11:27:24 by lukg »

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #185 on: 31 / May / 2008, 15:22:03 »

This is the palette I've used (zipped). I can't take a good palette anymore, I don't know why, it's like to win a lottery.

zSHARE - palette.zip

Logged

lks

16
[A570IS, S5IS]

Re: New project: camera color profile calculation

« Reply #186 on: 31 / May / 2008, 21:08:43 »

I tried calibrating the S5 today. I took a picture of the Gretag-Macbeth color chart in 3pm sunlight. The best result I got was this with Im. Bright = 0.75:

Code: [Select]

RESULTS
White area: 9
Errors:
Zone 1: 11.1%
Zone 2: 10.8%
Zone 3: 10.7%
Zone 4: 4.2%
Zone 5: 10.3%
Zone 6: 4.9%
Zone 7: 7.8%
Zone 8: 10.6%
Zone 9: 6.0%
### Max error is greater then 10%, RESULTS ARE POOR ###
Camera -> XYZ matrix:
1.558489 0.923604 0.792446
0.260645 2.211214 -0.107758
0.044825 -0.855401 6.696108
XYZ -> Camera matrix:
0.698670 -0.325843 -0.087927
-0.083100 0.493829 0.017781
-0.015293 0.065266 0.152201

Unfortunately it doesn't appear much better than lukg's. I do note that if I use tint +10 in ACR that it looks pretty close, though.

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #187 on: 01 / June / 2008, 06:59:41 »

Thanks lks, if you have a real gretag color chart you can provide better results than everyone else. Keep trying, play with focus and zoom.
I have a question for the author or anyone knows...does this method depends on the palette provide in the first post?? because i tried with different color palette with horrible results (errors of about 100000%).

EDIT: LKS, I tried your matrix, but it doesn't match colors with my 3 test pics. It gives colder colors sometimes and warmer colors in other pics (like the a720matrix). It's a mission impossible, in my opinion. I'm worry that in this way, there are millions of good matrix for the calibration pic, but only few are good for any other picture too. Anyway I hope we'll find some of those.

« Last Edit: 01 / June / 2008, 13:16:30 by lukg »

Logged

lks

16
[A570IS, S5IS]

Re: New project: camera color profile calculation

« Reply #188 on: 01 / June / 2008, 16:25:07 »

I agree my last calibration is not that great. I tried again and got the following slightly better results:

Code: [Select]

RESULTS
White area: 9
Errors:
Zone 1: 10.3%
Zone 2: 3.9%
Zone 3: 8.0%
Zone 4: 9.5%
Zone 5: 9.4%
Zone 6: 10.2%
Zone 7: 9.9%
Zone 8: 5.9%
Zone 9: 4.6%
Zone 10: 1.4%
### Max error is greater then 10%, RESULTS ARE POOR ###
Camera -> XYZ matrix:
1.761105 0.931603 0.791588
0.325948 2.337791 -0.149091
0.065097 -0.923729 6.943318
XYZ -> Camera matrix:
0.622181 -0.278327 -0.076910
-0.087866 0.470720 0.020125
-0.017523 0.065233 0.147422

If in addition I manually set white balance in Adobe Camera Raw and then set the camera calibration tab (based on http://www.21stcenturyshoebox.com/tools/ACRcalibrator.html) to the following settings:

Code: [Select]

Red Hue, Sat:  -1, -38
Green Hue, Sat: 51, 42
Blue Hue, Sat: 6,18

then the result seemed better on a few test pictures. This is still a bit too much work for my tastes, though.

Logged

lukg

162
Eos 450D+18-55is+55-250is & Powershot S5is - 1.01a

Re: New project: camera color profile calculation

« Reply #189 on: 01 / June / 2008, 18:21:54 »

You're right! I tried to create a calibration setting in camera raw too but with no absolute solution that could be good for all my pictures (maybe cause i don't have a gretag chart, I don't have the skill and there are too many combinations

). The only thing I noticed is:
-with my matrix and yours, if you set RGB channels hue to +100 and saturation to -100 I think (i suppose) that you should get a gray scale image. But the image is not gray. If you set Blue or red or green channel sat to -50 you get a gray scale image. This is the point from where I started but I lost my patience soon

I'm really thinking that the camera apply some further strange algorithm from Raw to Jpg instead of a simple color transformation (selective color boost or something else). Maybe i'm wrong, I don't know much about camera working and color theory

.
Anyway for what I see your latest matrix is way better than the previous one. I see also that you too got only 10 zones instead of 22 (or 24)...and for what I understood, it is not a good thing.

« Last Edit: 01 / June / 2008, 20:52:41 by lukg »

Logged