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New project: camera color profile calculation

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Offline snc

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Re: New project: camera color profile calculation
« Reply #400 on: 26 / March / 2009, 05:40:18 »
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yup, got it... a fellow 970 user took them, cause my cam was gone for a while... took new images with my cam, but same problem. anyway, the sx10 and ixus970 sensors seem to be extremely similar, if not identical.
surely some more experienced photographer can come up with "better" images from the 970, but i am not sure that it would help...

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Offline ewavr

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Re: New project: camera color profile calculation
« Reply #401 on: 26 / March / 2009, 06:46:24 »
yup, got it... a fellow 970 user took them, cause my cam was gone for a while... took new images with my cam, but same problem. anyway, the sx10 and ixus970 sensors seem to be extremely similar, if not identical.
surely some more experienced photographer can come up with "better" images from the 970, but i am not sure that it would help...

@scn:

Try also semi-official color matix from G9 (http://lclevy.free.fr/cr2/):

#define CAM_COLORMATRIX1                               \
  7368, 10000,  -2141, 10000,  -598 , 10000, \
 -5621, 10000,  13254, 10000,  2625 , 10000, \
 -1418, 10000,   1696, 10000,   5743, 10000

also try with this matrix:
#define cam_CalibrationIlluminant1 21 // D65

For current SX10 matrix, reds are oversaturated (like to many other cameras: SX100, A720, S5IS).
With this matrix, reds are slightly undersaturated.
Violet colors in both matrix are more violet than in jpeg, but they (in dng) are more similar to the real colors (due to  suppression of chromatic aberrations in camera jpeg ?).
« Last Edit: 26 / March / 2009, 06:57:35 by ewavr »

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Offline snc

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Re: New project: camera color profile calculation
« Reply #402 on: 26 / March / 2009, 10:11:42 »
Did you give it a shot with NIP2? There is a nice tutorial here: http://www.vips.ecs.soton.ac.uk/index.php?title=Colour_calibration_with_nip2&printable=yes

Attached see the image I quickly did with it, and your sample pic. It shows the color matrix it calculated, I suspect it could be used for our purpose as well. Just I didn't have time to look into it yet. Either the values need to be ordered correctly, or the matrix has to be inversed for the transformation... Suspect that a value like 107.07 would be 1.0707 in "our" terms... that would make sense, judging from the scale of them.

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Offline whoever

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Re: New project: camera color profile calculation
« Reply #403 on: 26 / March / 2009, 12:52:53 »
Did you give it a shot with NIP2? There is a nice tutorial here: http://www.vips.ecs.soton.ac.uk/index.php?title=Colour_calibration_with_nip2&printable=yes
...
For this to work, you need the real G-M color-checker, not an on-screen fake (plus you need a standard light source). Overall, to calibrate anything, you need a calibrated source. (ArtDen's logic in dng4ps2 is something different from calibration, even though it may produce useful results.)


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Offline snc

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Re: New project: camera color profile calculation
« Reply #404 on: 27 / March / 2009, 02:23:24 »
well, you are right with that, of course. but as i said, it was merely a quick test. what i am trying to work out with this is some principle that i could apply. the test image that was processed there surely should give us some "close enough" result as proof-of-concept, should it not?
and really, i am willing to get a color checker chart - it's not like they are hellishly expensive, after all. plus, i have the access to standard light sources and additional color charts.
« Last Edit: 27 / March / 2009, 04:56:05 by snc »

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Offline zosX

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Re: New project: camera color profile calculation
« Reply #405 on: 28 / March / 2009, 06:58:51 »
CALCULATION
Area 1
jpeg color r=0.50, g=0.08, b=0.37
camera color r=0.21, g=0.12, b=0.08
Area 2
jpeg color r=0.00, g=0.01, b=0.18
camera color r=0.00, g=0.02, b=0.03
Area 3
jpeg color r=0.08, g=0.39, b=0.00
camera color r=0.09, g=0.17, b=0.03
Area 4
jpeg color r=0.37, g=0.01, b=0.00
camera color r=0.14, g=0.04, b=0.01
Area 5
jpeg color r=0.60, g=0.47, b=0.53
camera color r=0.28, g=0.31, b=0.14
Area 6
jpeg color r=0.69, g=0.57, b=0.52
camera color r=0.34, g=0.38, b=0.15
Area 7
jpeg color r=0.77, g=0.67, b=0.51
camera color r=0.42, g=0.47, b=0.16
Area 8
jpeg color r=0.53, g=0.66, b=0.19
camera color r=0.29, g=0.39, b=0.10
Area 9
jpeg color r=0.42, g=0.63, b=0.12
camera color r=0.24, g=0.35, b=0.09
Area 10
jpeg color r=0.45, g=0.66, b=0.58
camera color r=0.25, g=0.39, b=0.15
Area 11
jpeg color r=0.55, g=0.70, b=0.04
camera color r=0.31, g=0.39, b=0.08
Area 12
jpeg color r=0.73, g=0.64, b=0.43
camera color r=0.39, g=0.43, b=0.15
Area 13
jpeg color r=0.66, g=0.71, b=0.56
camera color r=0.35, g=0.46, b=0.17
Area 14
jpeg color r=0.78, g=0.70, b=0.46
camera color r=0.44, g=0.49, b=0.16
Area 15
jpeg color r=0.00, g=0.02, b=0.24
camera color r=0.01, g=0.03, b=0.04
Area 16
jpeg color r=0.59, g=0.17, b=0.37
camera color r=0.25, g=0.17, b=0.10
Area 17
jpeg color r=0.23, g=0.52, b=0.16
camera color r=0.16, g=0.27, b=0.08
Area 18
jpeg color r=0.35, g=0.25, b=0.15
camera color r=0.17, g=0.17, b=0.06
Area 19
jpeg color r=0.56, g=0.65, b=0.07
camera color r=0.31, g=0.37, b=0.08
Area 20
jpeg color r=0.77, g=0.49, b=0.25
camera color r=0.40, g=0.36, b=0.11

RESULTS
White area: 13
Errors:
Zone 1: 7.0%
Zone 2: 9.2%
Zone 3: 9.4%
Zone 4: 9.5%
Zone 5: 8.6%
Zone 6: 7.4%
Zone 7: 5.5%
Zone 8: 2.9%
Zone 9: 8.8%
Zone 10: 9.1%
Zone 11: 2.2%
Zone 12: 3.6%
Zone 13: 5.7%
Zone 14: 9.4%
Zone 15: 9.5%
Zone 16: 3.2%
Zone 17: 6.2%
Zone 18: 7.6%
Zone 19: 3.5%
Zone 20: 8.5%
Camera -> XYZ matrix:
0.983613 0.279535 0.814647
0.154812 1.559721 -0.447597
-0.195736 -0.653666 5.720120
XYZ -> Camera matrix:
1.023507 -0.252814 -0.165548
-0.094643 0.686256 0.067178
0.024208 0.069771 0.176833


20 zones are good enough?? I think I've just perfected the matrix for the 590IS rev 1.01B.

First of all the noise on the CCD makes this calibration really HARD. It took two hours to get 20 zones out of my crappy test image. Secondly I highly recommend anyone attempting this get a test target and shoot that in really bright light. Underexposure leads to noise which makes everything all the more difficult.

Test files are at: http://rapidshare.com/files/214496507/test.zip.html

Sorry they are kind of crappy. I didn't realize how dirty that target was until I looked at the files at home.

Re: New project: camera color profile calculation
« Reply #406 on: 14 / April / 2009, 16:01:21 »
From postings seen DNG4PS2-0.2.3 build 256 is latest.

Went to download site http://code.google.com/p/dng4ps2/downloads/list and not found only dng4ps2-0.2.3-beta20.exe   for Windows.  Uploaded:     Feb 23, 2009 so seems have newer version with added IXUS 50 support.

Steve   

Re: New project: camera color profile calculation
« Reply #407 on: 29 / April / 2009, 16:00:14 »
Same trouble as ewavr http://chdk.setepontos.com/index.php/topic,390.msg30620.html#msg30620
Camera SX110, matrix the same is SX10.
10-bit RAW + JPG - http://www.zshare.net/download/59373244b43c4d91/


Re: New project: camera color profile calculation
« Reply #408 on: 07 / May / 2009, 23:44:51 »
In the link below there is a multi target picture taken with SX110. Maybe it can help to calculate the apropriate color matrix for SX110 (sorry, in the beta version of dng4ps made to SX110 - http://chdk.setepontos.com/index.php/topic,2838.msg32053.html#msg32053 -, there is no Calibrate button).

ColorCheck picture:

http://www.imaging-resource.com/PRODS/SX110IS/FULLRES/SX110IShMULTIW.HTM

Re: New project: camera color profile calculation
« Reply #409 on: 10 / May / 2009, 15:00:56 »
Same trouble as ewavr http://chdk.setepontos.com/index.php/topic,390.msg30620.html#msg30620
Camera SX110, matrix the same is SX10.
10-bit RAW + JPG - http://www.zshare.net/download/59373244b43c4d91/

Did you already deleted the 2 bit?

I hope someone could make a working color matrix...
« Last Edit: 10 / May / 2009, 15:02:53 by Obihoernchen »
Canon PowerShot SX110 IS
CHDK: at Autobuild now
Wiki: SX110IS

 

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