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Author Topic: State of the art camera profiling software?  (Read 41595 times)

digitaldog

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Re: State of the art camera profiling software?
« Reply #40 on: March 08, 2015, 05:46:22 pm »

ICC (organization) can say whatever they want - the reality is different... I guess you do not dispute that rawdigger + argyll based example was provided to you before, no ?
digitaldog intentionally writes FUD
you are totally clueless...
You haven't been around these parts long or written many posts. But just the one's today have convinced me that you deserve your very own spam filter so that whatever comes my way from LuLa from you goes where it belongs.
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digitaldog

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Re: State of the art camera profiling software?
« Reply #41 on: March 08, 2015, 05:52:23 pm »

Lightroom has some crude camera calibration adjustments, and then it has a color tool where can make various adjustments by selecting hue, but you can't select "dark red" and make a hue adjustment and then select "light red" and make a different hue adjustment (or lightness/saturation).
Those are largely hurt me buttons for most users. If a fixed slider gets the job done, I'm fine with that.
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With RGB curves you can make some of these effects but it's more difficult to work with.
If the task can be achieved as I believe you are referring to (subjective editing) I'd suggest that or other rendering tools are both more appropriate and easier for users than building then editing a DNG camera profile.
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The best and most flexible color edit tools in a raw converter I've come across is what's found in Capture One, with it's color editor you can make advanced selections. But I think there are still a few edits that is done in bundled color profiles you can't do in that color editor.
Fair enough, perhaps C1 and Adobe need to better provide selective color editing tools to do so. But I hear what you're saying, I still wish for the kinds of tools I had back with LinoColor that offered very powerful selective color editing tools. Point is, baking those kinds of edits into a profile (DNG or ICC) seems difficult for the end user and at the wrong place in a raw converter. But if people what to use a scientific calculator to figure 15% of the restaurant tip, go for it.  ;D
« Last Edit: March 08, 2015, 09:21:50 pm by digitaldog »
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samueljohnchia

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Re: State of the art camera profiling software?
« Reply #42 on: March 08, 2015, 09:00:24 pm »

I've some limited experience with DNG camera profiles. All the custom profiles I have made in the DNGPE are better than the results I get from QPcard and X-rite's Colorchecker Passport software. The latter two tweak the matrices, by 'guessing' at the camera's response from the photographed color target. However, the LUT adjustments that these profiles make usually robs the profile of some smoothness. One can see rough transitions in blurry out of focus areas for example.

On some of the ways processing engines affect color, I've also noticed that for LR/ACR PV2010 thinks more colors are blown than they actually are (confirmed by checking in rawdigger), while PV2012 applies aggressive highlight recovery by default, and it is extremely hard to move the sliders around to a point where no highlight recovery is applied. Regardless, I see that PV2012 tends to maintain better looking color in the brightest highlights. Warm daylight colors in PV2010 that are clipped or close to clipping tend to be shifted in hue towards green, while PV2012 maintains a more pleasing color. This is true regardless of the camera profile, Adobe Standard (with hue twists) or my custom daylight DNGPE profile. To observe this phenomenon, zero all the sliders in PV2010, save a copy, then convert to PV2012 and save another copy to compare. So no user additional edits can be blamed for contributing to this shift in color.

I believe I read Iliah Borg on the colorsync list commenting about how camera profiles should be a simple matrix profile, built from monochromator data, with no LUTs involved. That is how Adobe does it to derive their color transform matrices.

Here is a link to a presentation by Wayne Bretl, where he discusses some of the trade offs in mapping color from camera sensors. I think it offers some insight on how to derive the color matrices and the tradeoffs, which you might be interested in.

This is a very intriguing thread. Thank you for starting it Torger, I sincerely hope you figure this out! I tried to about a year ago and couldn't crack it.
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torger

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Re: State of the art camera profiling software?
« Reply #43 on: March 09, 2015, 03:28:46 am »

Great post Samuel, and great link. Will look at that presentation in detail (haven't had time yet), it seems to answer lots of questions I have.

The efficiency of pure matrix profiles are indeed an interesting subject. Maybe with "perfect" XYZ coordinates of the RGB primaries color can be very accurate, although the quick look at the presentation seems to suggest that is not the case. One thing is for sure that a camera is more linear than both printers and screens, as linear as it gets, but the color filter responses are not ideal for color matching.

How accurately will a greg macbeth 24 patch profile place the RGB primaries compared to a CFA method is one question. I noted that the camSpecs product had three methods to calculate the RGB primaries from the CFA response, if we're lucky those methods are documented in the literature somewhere so one can test, seems to be a few leads in the presentation. I don't need to get a monochromator for experiments as there's public Nikon D5100 data available for example, and imaging resource has shots of both the 24 patch colorchecker and the larger SG.

You can make basic subjective adjustments with a matrix profile too, like increasing saturation and I *think* Adobe typically does that, ie their matrices are not designed for maximum accuracy but to provide a good basis for that saturated "Adobe Standard" look.

Pure matrix profiles are often favored by "photo hackers" as they have perfect smoothness and perfect linearity (great for HDR merging for example), but if they can actually make reasonable accurate colors I don't know. I've got the sense that they're often quite off, but that may be due to the design method, ie for placement of RGB primaries due to test target limitations, or a subjective placement from a vendor to produce a "look". Possibly the only reason to use a LUT is to make subjective adjustments, but I do doubt it, my current guess is that even with a "perfect" matrix profile you would get improvements in accuracy by adding LUT adjustments.

Another frustrating thing in terms of the lack of profiling software is that there are no good profile evaluation tools, for example to make smoothness vs accuracy tradeoffs in a LUT profile, you have to test with real images and hope that you see, or use a tool like DcpTool and try to visualize how the listed hue/saturation adjustments will affect smoothness.

I think the lack of profiling software and general profiling experience among photographers have created a mythology around camera color. Many think the color is more strongly bound to the hardware than it actually is, and it can be the reason why some pay 4 times the price for an IQ250 rather than a 645z which has the same sensor, just because Capture One IQ250 profile color is subjectively better. I'm convinced that the CCD vs CMOS often debated in MFD forum is more about profiling than hardware differences. If there was proper tools for profile editing and available knowledge how to make great subjective profiles photographers could take some power back from the vendors...

It seems like camera profiling is the least developed aspect of photography color management.
« Last Edit: March 09, 2015, 04:04:59 am by torger »
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torger

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Re: State of the art camera profiling software?
« Reply #44 on: March 09, 2015, 04:15:09 am »

Looking a bit more at the presentation it seems like a pure matrix profile is not the "ultimate" answer concerning accuracy and gamut coverage. A LUT is required. It should be possible to create that LUT from the CFA responses.

With a matrix profile you miss out on some colors, and create some false out-of-gamut colors. I have before noted that matrix profiles can make colors even outside ProPhotoRGB, but those colors are not real colors...

Also worth noting that there are no "correct" positions of the RGB primaries in the matrix profile, but there's tradeoffs to make between say gamut coverage and chroma noise. Additionally there's also an accuracy tradeoff, a matrix can be optimized to match some colors better than others, which suggests that a matrix derived from a test target with "important colors" may be better than a purely analytical method.
« Last Edit: March 09, 2015, 07:13:30 am by torger »
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Czornyj

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Re: State of the art camera profiling software?
« Reply #45 on: March 09, 2015, 09:17:11 am »

It seems like camera profiling is the least developed aspect of photography color management.

For a good reason.

Standard CMF used in color management is a very simple model of specific human perception condition. It works well in a stable, controlled environment, and characterises the way how we perceive small color stimulants under D50 lighting.

There's no chance it could work flawlessly in case of digital camera that captures colors in a completely different way than a human eye, and - to make things even worse - in various lighting conditions. No matter what method you'll use, it will eventually fail for some colors, or in some lighting conditions. All you can do is to find the best compromise, but there's no magical method to get significantly "better results" with some more sophisticated tools or magical camera profiling method (as long as it's based on standard CIE XYZ colorimetry).

What we would need to achieve better results is a science-fiction camera and next generation RAW converter, not better camera profiling tools.
« Last Edit: March 09, 2015, 09:28:45 am by Czornyj »
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torger

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Re: State of the art camera profiling software?
« Reply #46 on: March 09, 2015, 10:38:21 am »

For a good reason.

I don't think so. As discussed in this thread there's more to camera profiling than making accurate colors. There's the subjective tuning of profiles too, and those aspects are really limited in current software. Vendors have their own inhouse tools to make profiles, because no software on the market is flexible enough.

Reproducing skin tones "just right" for your studio portraits is a more about art than accuracy, but to perform this art you need tools and knowledge how to tune this. All this is missing in the tools I've found so far.

It is however a good situation that photographers can't make profiles with "vendor look" if you're Phase One for example. One of the main selling points of Capture One is that color in Adobe Lightroom is (subjectively) much worse even for the same cameras, and there are no good tools for the photographer at hand to design their own look that they like. Capture One supports the IQ250, but not the massively cheaper 645z both with the same sensor. A major selling point is that IQ250 color is subjectively better, and that's (almost) only about the profile. Few photographers understand it though, as camera profiling is not a well-known subject.

If there's something to gain from making the base profile using measured CFA responses like the vendors do instead of using reflective targets is less certain I guess (especially if we're satisfied with Pointer's gamut), maybe it's more about efficiency than quality. Once you've measured the CFAs you can use any type of design method to make your profile without having to pull out the camera again (oh well, you'll still have to do your subjective adjustments on real shots). I guess the only way to find out is to test, or ask someone that is experienced with both methods.
« Last Edit: March 09, 2015, 10:41:36 am by torger »
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digitaldog

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Re: State of the art camera profiling software?
« Reply #47 on: March 09, 2015, 10:41:31 am »

I don't think so. As discussed in this thread there's more to camera profiling than making accurate colors. There's the subjective tuning of profiles too, and those aspects are really limited in current software.
I strongly agree with Czornyj and further, those tools you desire should be placed outside an ICC profile or DNG profile. Not their job. As for 'accurate' color, major rabbit hole like many aspects of this discussion.
« Last Edit: March 09, 2015, 10:43:28 am by digitaldog »
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torger

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Re: State of the art camera profiling software?
« Reply #48 on: March 09, 2015, 10:50:09 am »

I agree with Czornyj and further, those tools you desire should be placed outside an ICC profile or DNG profile. Not their job. As for 'accurate' color, major rabbit hole like many aspects of this discussion.

Well, I agree, but the raw converter vendors don't, and actually I think most users actually prefer to have a base look delivered by the profile. Subjective look is currently very much controlled by the profile in the major raw converters, and the tools inside the raw developer typically don't allow for the type of fine-tunings done in a profile.

On the second point you can always run the argument that since absolute accuracy is not possible (as we all know) you can reduce test target gamut coverage further, and dumb down the profiling process even more. Maybe it's true that 24 patch greg macbeth is already way past the limit of diminishing returns, but I'd like to find some better documentation on that than I've found so far, or make my own experiments that can reach to that conclusion.
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digitaldog

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Re: State of the art camera profiling software?
« Reply #49 on: March 09, 2015, 11:00:01 am »

Subjective look is currently very much controlled by the profile in the major raw converters, and the tools inside the raw developer typically don't allow for the type of fine-tunings done in a profile.
Can be yes! Doesn’t have to be, wasn't designed to be, rather difficult to achieve compared to editing tools in a raw converter. Do we need better selective color rendering tools? Sure. Is a profile the place to do this? I and others think not.
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On the second point you can always run the argument that since absolute accuracy is not possible (as we all know) you can reduce test target gamut coverage further, and dumb down the profiling process even more. Maybe it's true that 24 patch greg macbeth is already way past the limit of diminishing returns, but I'd like to find some better documentation on that than I've found so far, or make my own experiments that can reach to that conclusion.
There lies a huge issue; the gamut of the target itself and the fact our camera systems don't really have a color gamut. And the illuminant and conditions we shoot that target. And how it's processed. As was mentioned here already, treating a camera system like a display or printer in terms of targets, measurements and other processes is fraught with issues. Been that way since way back in the ColorBlind days of ICC color management, hasn't changed much since.

IF the problem is rendering the raw image as you or I desire, we need better rendering tools in the converter. And it's possible we could get them.
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AlterEgo

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Re: State of the art camera profiling software?
« Reply #50 on: March 09, 2015, 11:14:38 am »

maybe I would find out that the monochromator/CFA method would be no more effective than a greg macbeth 24 patch color checker though, and then I would cry a bit ;)

there mere fact that OEM profiles are not done off 24 patches says that you have a chance to do better - may be you can create your own target for example... there was one person (do not remember where I saw his postings @ colorsync list or here) who actively engaged in creating his own targets for camera profiling (you have spectrophotometer, so you can measure patches for argyll)... he was using some paints and color chips and cuts from exisitng targets and so on, as far as I remember... I think his name was Ben Goren... this dude = http://trumpetpower.com/photos/Exposure
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torger

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Re: State of the art camera profiling software?
« Reply #51 on: March 09, 2015, 11:23:41 am »

there mere fact that OEM profiles are not done off 24 patches says that you have a chance to do better - may be you can create your own target for example... there was one person (do not remember where I saw his postings @ colorsync list or here) who actively engaged in creating his own targets for camera profiling (you have spectrophotometer, so you can measure patches for argyll)... he was using some paints and color chips and cuts from exisitng targets and so on, as far as I remember... I think his name was Ben Goren... this dude = http://trumpetpower.com/photos/Exposure

Thanks for the reference, I'll have a look, looks like a really nice user article on the net similar to what I'm thinking about doing.

There's also "HueLight" the guy that sells color profiles to the 645z for example (and people buy them because many are not satisfied with Adobe defaults), as far as I know he uses some self-devised custom method to make his profiles, and adds hand-tuning. Subjective fine-tunings will never be a "mainstream" function, it will be for advanced users with a special eye for color. Therefore I think it's unlikely that we'll see corresponding fine-tune functions inside Lightroom for example.
« Last Edit: March 09, 2015, 11:26:23 am by torger »
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TRANTOR

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Re: State of the art camera profiling software?
« Reply #52 on: March 09, 2015, 11:40:30 am »

TL;DR

There is no way to make good profiles with reflection target. And no chance to make profiles that is colorimetric accurate in general because sensors do not correspond Luther-Ives condition. Only "pleasure color reproduction" rule way to make these things right.


I make some profiles that uses sensor's CMF (color matching functions, spectral responses).

ICC (for Capture One):

https://www.sendspace.com/file/f951ee
https://www.sendspace.com/file/tw6uw5
https://www.sendspace.com/file/277362
https://www.sendspace.com/file/8f2gsq
https://www.sendspace.com/file/dsx7wp
https://www.sendspace.com/file/5dxgl1

DCP (LR, ACR etc):

https://www.sendspace.com/file/lpru4k
https://www.sendspace.com/file/420pg5
https://www.sendspace.com/file/p7b1jh
https://www.sendspace.com/file/cdihaj


Enjoy.


PS. Sorry for my bad english. =)

torger

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Re: State of the art camera profiling software?
« Reply #53 on: March 09, 2015, 11:48:36 am »

Thanks Trantor. I'll certainly have a look.

Would you mind sharing a little about which method/software you have use to create these profiles? I'm very curious to hear...
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AlterEgo

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Re: State of the art camera profiling software?
« Reply #54 on: March 09, 2015, 11:49:13 am »

There's also "HueLight" the guy that sells color profiles to the 645z for example (and people buy them because many are not satisfied with Adobe defaults), as far as I know he uses some self-devised custom method to make his profiles, and adds hand-tuning.

He does, he got once into a shouting match with Eric Chan :D , as far as I remember the postings in some U2U Adobe-hosted forums ... but I do not recall him sharing his methods or anything that you might be interested in... for such things you really can try to engage directly people behind the profiles in actual raw convertes - Chan or BG of Iridient or Borg of RPP or even what was his name... Kuhlmann or Esben Myosotis (???) from PhaseOne ... the skillfully posed polite question goes a long way, while not creating an impression that you are trying to extract something that they consider a trade secret... so you really need to spend time thinking what and how to ask and then you might score a knowledge
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AlterEgo

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Re: State of the art camera profiling software?
« Reply #55 on: March 09, 2015, 12:14:51 pm »

Thanks Trantor.
I recall somebody (3rd party) posted about his profiles @ http://www.rudtp.pp.ru last year... examples were good (or very good)
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TRANTOR

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Re: State of the art camera profiling software?
« Reply #56 on: March 09, 2015, 12:17:21 pm »

method/software you have use to create these profiles?
I make my custom software. Actually all calculations does in Matlab plus sort of handmade works (eg matrix fitting, whitepoints iteration etc).

Schema is: CMF + spectral "paths" (~50K items) + spectra of selected illuminants (A, D50, D65 etc) -> sensor gamuts under selected illuminants -> warping (Shepard's method) sensor gamuts to human gamuts under selected illuminants -> LUT's for every illuminant -> resulting profiles.

TRANTOR

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AlterEgo

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Re: State of the art camera profiling software?
« Reply #58 on: March 09, 2015, 12:38:20 pm »

the starting point for OP this way is - either procure spectral response for a particular camera (sensor + CFA + whatever optics on top) from manufacturer or buy/rent monochromator (or make some friends in a local university/etc with such equipment available) to measure
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digitaldog

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Re: State of the art camera profiling software?
« Reply #59 on: March 09, 2015, 12:40:06 pm »

Thanks for the reference, I'll have a look, looks like a really nice user article on the net similar to what I'm thinking about doing.

You should contact Eric Walowit and talk to him about his idea of capture specific profiles done on the fly when shooting while measuring the actual capture illuminant. Contact me off list and I'll give you his email. What Eric proposes makes so much more sense than treating a digital camera like a printer in terms of a profile.


https://www.linkedin.com/pub/eric-walowit/4/4a0/793. No armchair's anywhere near this fellow.
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