imbedded profile

[ljl269]

My congrats to all involved for a well designed site with great content. Any site that yields relevent info in < 5 mins I join!

Attached r 2 GretagMacbethColorChecker where 1 has an imbedded profile. These look a bit different to me no matter what I enable in Ulead's PI8 Color Management.

1-Is the idea that the image with the imbedded profile will display accurately on any calibrated monitor & print accurately on any printer that recognizes imbedded profiles? Here accurately means matches to the eye the purchased GretagMacbethColorChecker.

2-What profiles r embedded? I thought it would be monitor but 1 site said it's capture device.

BTW Color Management is about the most difficult subject associated with a PC 4 me.

Your help is MUCH appreciated. Any Comments/ suggestions/corrections appreciated.Thanks- bye- Larry

[Vikki]

I'm not sure what you're asking.
If you want to compare images with and without profiles, you would use the same image.

Maybe this will help (not to be considered an expert at this though) Think of embedded profiles as a "code" that tells a device how to render colors.

As an analogy, think of a profile as a box of crayons.
My camera uses sRGB crayons and colors reds using the red2 crayon.
However, my monitor uses an aRGB box of crayons. It has a few crayons that look red, but doesn't have the red2 crayon. So, the monitor will make a substitution, and use a medium red crayon.

To make it even crazier, my printer uses Epson crayons, and doesn't have either of the red crayons used by my sRGB crayons (camera) or aRGB crayons (monitor). It only has a redx crayon.

Now, when I see the image on my monitor, the reds may not look like the actual color I saw when I took the picture, because it's not able to produce the same red color. When I go to print the image, it doesn't look like the image on my screen because the printer doesn't have the same exact red used by my monitor.

Embedded profiles tells the device which crayons were used to for the image. Soft profiling allows you to "preview" how the image will look when "colored" using different "crayons" .

Bottom line: When you have an image from your camera or scanner, if it has a profile, your program will know which box of crayons was used, so that it can render the image as accurately as possible, using the box of crayons it has. You can then tell the program to "convert" the profile to your printer's profile, so that it knows how to convert the colors using the crayons your printer has available.
Does that make sense?

[Chip Hildreth]

Vikki, that was without a doubt the best plain english description of basic color management I have ever seen.

I can only add, and my plain english will not be so good, that profiles go with devices like monitors, printers, cameras, etc. The profile that probably matters most is the printer, or more specifically, the printer/paper combination. Say your working with the epson crayons and you print on a piece of plain old bond paper and then you print on a piece of very expensive, glossy epson paper... the color checker will look different on each print. The printer software needs to know what kind of paper you're using so it can adjust how much of each crayon to use to get as close to the expected color as possible.

Color management and profiling are a big ball of wax that is hard to get you brain around, at least for a while. But once you start to get it figured out with your particular system, it will be a simple set of steps to take each time to make sure everything (all your devices, paper and inks) is in harmony and reading from the same page. From a printing perspective, you can look into Harald Johnson's book, 'Mastering Digital Printing'. He also has a helpful website, 'www.dpandi.com'.

Lastly, beware, this is a subject involving many possible solutions to a single set of problems and opinions are many... and often strongly stated as though they were gospel. You have to work out your own methods. You'll know they are right when the results are good, as expected, and repeatable.

[Vikki]

Thanks Chip, but I can't take full credit for that analogy.
Gary Box was my inspiration. I read this quite a while ago, and upon reading it again just now, I think in my interpretation I've clumped "color profiles" and ""color spaces" into one.
Even so, putting it in these terms has helped me comprehend these issues, and I wanted to pass it on, as I know so many people are struggling with this.
Good point to mention the paper profiles.
To read Gary's article:
Click on: Understanding Colorspace
Also read: Device Profiles (link on his site)

[ljl269]

Thank you for such a quick response.

RE:'I think in my interpretation I've clumped "color profiles" and ""color spaces" into one"- I was gonna suggest color spaces = brand of crayon(or paints).

Comments/suggestions/corrections appreciated.
Thanks- bye- Larry

[ljl269]

QUOTE=Chip Hildreth] Lastly, beware, this is a subject involving many possible solutions to a single set of problems and opinions are many... and often strongly stated as though they were gospel. You have to work out your own methods. You'll know they are right when the results are good, as expected, and repeatable.[/quote]

This is atually a subproblem that arose from calibrating my monitor which, without extra hardware, has many solutions (like 2 equations with 3 unknowns). I have at least 3 that will pass 'gray pattern tests' at 3 sites but fail some real-world tests(from which this question arose). I think ur advise above is applicable to monitor calibration.

From experimenting I'm trying to get a list of tests & general guidelines. IE: in nVidia driver, Gamma correctionms > 10% probably dont work very well outside of 'gray pattern tests' !

That will be subject of a later post so I dont want to say 2 much. Thanks- bye- Larry

[Chip Hildreth]

My work involves mostly paper and ink so my perspective is very print oriented. I use Adobe Gamma to adjust my monitor for changes in lighting conditions and I use soft proofing in Photoshop as a rough guide. Otherwise, I'm pretty ignorant about color management for monitors.
I thought I should at least try and address your original questions with what I've learned so far. Expect dissenting opinions and corrections from others. I'm certain to miss things or be mis-understood... but it's a start in the right direction.

Originally Posted by ljl269

1-Is the idea that the image with the imbedded profile will display accurately on any calibrated monitor & print accurately on any printer that recognizes imbedded profiles? Here accurately means matches to the eye the purchased GretagMacbethColorChecker.

The embedded profile is a color key specific to a device like a camera, monitor, scanner or printer and it's used in conjunction with a reference model to render colors as accurately as possible on a different device with different color capabilitiy. Everything has to be coordinated in terms of the reference model, how the file is to be used and at what point the profiles are applied. It is very likely the colors will not match between different devices and the original because light and color work differently on monitors and paper and, practically all devices have different capabilities when it comes to rendering color..

2-What profiles r embedded? I thought it would be monitor but 1 site said it's capture device

Originally, it's the capture device, usually camera or scanner, but it can be converted to any other device profile and saved that way. The capture device profile is a description of what colors the device can record and what values it assigns to those colors (device charaterization). It's what set of crayons the device uses. sRGB is the general purpose profile for PC monitors running windows and is almost a standard for digital cameras and scanners. It's the safest profile for display applications and it prints most images well too.

BTW Color Management is about the most difficult subject associated with a PC 4 me.

Like I said earlier, it's difficult at first but you can get the hang of it by being methodical. As you work with it, you will make happy mistakes that work perfectly. Research those mistakes to figure out what went right and learn to repeat them. Then, it's easy to find information and opinions backing up what you did. When I was first trying to use color management to print, I wasted $140 worth of fine art paper trying to match a painting. About two thirds of the way through, I got a match but couldn't repeat it. Turned out I was applying the same profile twice and that one match happened when I forgot to tell the printer to apply the profile. I later learned that double profiling was a common issue.
These days, I have a standard workflow for printing to the printers for which I have profiles and most of it is safely recorded in Photoshop actions so I don't screw up.

[Duv]

"These days, I have a standard workflow for printing to the printers for which I have profiles and most of it is safely recorded in Photoshop actions so I don't screw up."

This idea seems pretty tasty. Could you supply details of your workflow as a rough guide to others?

Cheers
Dave

[Chip Hildreth]

Dave,
I'm happy to pass this on though you should take it with a big grain of salt. I'm not formally trained, this is just what I've figured out over time that happens to work for me with my equipment and software... which I should probably outline first.
I shoot either a Nikon D1X recording RAW files or film (6x7 or 4x5) and scan using an Imacon FT848 ccd scanner.
For the Nikon, I process the RAW files into TIFFs using Phase One's CaptureOne DSLR software, mainly because it makes RAW files easy to handle in batches. I keep the 'Nikon D1X Daylight' profile embedded the whole way through until I'm ready to print. With the Imacon I do kind of the same thing, scan RAW files and process them into TIFFs using Imacon's Flexcolor software. I keep the 'Imacon Flextight 848' profile all the way through until ready to output.
I print to several devices: an Epson P2200, an Epson 10000, a Xerox Phaser 6200 and various offset presses at our printer's. I only have usable profiles for the Epsons.
I pass virtually every file I print through Photoshop 7 because it gives me the control I want. I usually sharpen a little bit, last thing before converting the profile and printing. No matter what, I do all my PS work without changing the embedded profile until I'm absolutely ready to print. When I go to the Epsons, I convert the profile to the appropriate printer/paper profile (I use Ilford and Epson papers) and turn on soft-proofing just to see what changed. Typically the image loses some contrast and the reds shift slightly to the blue. I try to compensate for that with levels or curves prior to converting. When I click print I watch for the Epson preview, which is not color managed, and if it's heavy on the magenta, I print; if it looks normal, I stop and check my settings. Strange, I know, but it works. There's probably something I could do about it but, as yet, I haven't needed to.
One thing is for certain, if I don't like the print and need to make a change, I go back in the history to before I convert the profile to do it. Whenever I make changes to the file once the output profile is embedded I get color cast problems that I'm unable to correct.
So that's that for the Epsons which are the only cases of true, closed loop color management I use. When I print to the laser, I convert to 'Adobe RGB 1998' and let it rip. If I need to make changes, I go ahead and change them without backing up to the source profile. We mainly use that laser for proofing or printing from QuarkXpress... but that's another thread entirely.
When we go to offset press, I convert to CMYK as soon as I know that's what the destination is. Typically the image files are layed out in Quark or Illustrator once the manipulation and color correction are done so it's CMYK, CMYK, CMYK.
So far, we get good, reliable results and our printers love us because we send them files just like they want them.

That's really all there is. The PS actions are maily for converting the profiles and turning on the appropriate soft proofing.
It's funny, it seems so simple now... but I've wasted a lot of paper and ink getting to this point.

Is that useful to you?

[ljl269]

Thank you Vikki for such a quick response. Mine was not so prompt because I was reading, thinking, & experimenting to give some meat to my reply. Chip has brought-up some of the same issues in 3 subsequent posts so I will make my responses there since they break into subtopics similar to his posts.

I look forward to ur continued input on profiling.

Now I gotta find out how to get this thing to not QUOTE all the time.

Thanks- bye- Larry

[ljl269]

Thanks Chip. I'm gonna respond in several posts commenting on ur points in order i've researched them the most.

1-'I later learned that double profiling was a common issue', It is possible to double count- apply your monitors profile 1st in nVidia driver & 2nd time in color management.

2-'I have a standard workflow for printing to the printers for which I have profiles".Ofoto, a Kodak site, has no profiles and suggested I adjust nVidia driver so monitor matched the prints.Turning on Color Management for any of 6 printer profiles I have always results in an overall dark shift since printing is a reflective process as compared to monitors which are closer to a transparent medium like slides.In fact, times I've done this I had to use gamma multiplier of ~.7 which makes web pages awful dark.

3-viewing HP's profile 4 my monitor in my nVidia driver , the gamma ( see attachment ) looks like none I've seen. Can ihis be right?

Comments/suggestions/corrections appreciated.
Thanks- bye- Larry

[ljl269]

Hi Chip RE#2 & 'Originally, it's the capture device, usually camera or scanner, but it can be converted to any other device profile and saved that way'- R U saying that OUTPUT as well as input device profiles r carried with an indicator of color space(sRGB) & [(R,G,B) values for every pixel]. I suppose if my printer prints 126 on grayscale as red & urs prints it as 18% gray, u could lookup in my profile that I printed it as red and then look up red on ur profile as say pink.So withour my profile u print it as 18% but with knowledge of my profile u print it as pink? Perhaps its used in another way- this is only 1 I could think of.

I'll hae to think about what use my monitor profile would be to anyone but me.

Comments/suggestions/corrections appreciated.
Thanks- bye- Larry

[ljl269]

I took the 2 thumbnails and played with them seeing if I could do operations with both & if they have the same affect:

Notice that there is a difference in the profiled & non-profiled versions of GretagMacbethColorChecker even with Color Management OFF. Turning on Color Management & using HP's profile for my CompaqFS740 monitor darkens both & also produces noticable color shifts in both the profiled & non-profiled versions of GretagMacbethColorChecker . The shifts r in squares (2,1), (2,2), (2,6), (3,1), (3,4) but r minimal in the grayscale (row 4) & the greens. The RGB values of all pixels remain the same.

So now I know that imbedded profiles do NOT exempt the image from either visual driver effects (like gamma) or Color Management effects like soft-proofing.

The RGB values of images with imbedded profiles r only changed in the same ways as non-imbedded profiled images- levels, briteness,etc. The RGB values r correct for the image with the imbedded profile but not for the other image- (1,1) should be (114,81,64) but is (129,96,82) in the image without the profile but it may have just been created less accurately.

Comments/suggestions/corrections appreciated.
Larry

[Chip Hildreth]

Dude, you are working hard on this one aren't you! While I may not be of much help, I'm confident you will find what you're looking for. Here's my rather lame responses to your responses:

Originally Posted by ljl269

1-'I later learned that double profiling was a common issue', It is possible to double count- apply your monitors profile 1st in nVidia driver & 2nd time in color management.

That's interesting, makes perfect sense. I'm wondering if I had that problem a while back and didn't know it.

2-'I have a standard workflow for printing to the printers for which I have profiles".Ofoto, a Kodak site, has no profiles and suggested I adjust nVidia driver so monitor matched the prints.Turning on Color Management for any of 6 printer profiles I have always results in an overall dark shift since printing is a reflective process as compared to monitors which are closer to a transparent medium like slides.In fact, times I've done this I had to use gamma multiplier of ~.7 which makes web pages awful dark.

I think you should look in your monitor menu and set it to sRGB and leave the nVidia color management off. Use sRGB color profiles in your editing program and print sRGB... which may be as simple as telling the printer to not manage color. You will have to experiment. Like you say, the print can't match the monitor exactly but keeping everything sRGB should get you close. SRGB is a standard color space for web pages too.

3-viewing HP's profile 4 my monitor in my nVidia driver , the gamma ( see attachment ) looks like none I've seen. Can ihis be right?

It looks like the nVidia color correction dialog is for tuning the display. It seems like it should include a visual tool to aid in making the adjustments. I use Adobe Gamma but you might not have it. It gives you a dialog with grey references (two types) and you adjust brightness and contrast using the controls on your monitor proper; then you adjust a gamma slider in the dialog based on a visual judgement of one of the references; then you can save those settings in a monitor profile.

I'll respond to the other post too.
Good luck.

[Chip Hildreth]

OK, next one, this is more technical and there's lots of room for me to explain wrong... just keep that in mind.

Originally Posted by ljl269

Hi Chip RE#2 & 'Originally, it's the capture device, usually camera or scanner, but it can be converted to any other device profile and saved that way'- R U saying that OUTPUT as well as input device profiles r carried with an indicator of color space(sRGB) & [(R,G,B) values for every pixel]. I suppose if my printer prints 126 on grayscale as red & urs prints it as 18% gray, u could lookup in my profile that I printed it as red and then look up red on ur profile as say pink.So withour my profile u print it as 18% but with knowledge of my profile u print it as pink? Perhaps its used in another way- this is only 1 I could think of.

You just have one profile embedded at any given time and it is either an input profile or an output profile. An input profile is a very specific description of how a camera or scanner see and records color. The CMS needs it to know how the recorded color numbers compare with the internal reference model so it can convert the colors for another device like a monitor or printer. Input profiles are one-way, they are useful only as a source, not a destination. You can convert the embedded profile to an output profile, like sRGB, CMYK, or Adobe RGB (these are all general purpose profiles) which is more versatile. Output profiles are also color recording information specific to hardware devices. They go two ways so they can be used for source or destination conversions. This may have raised more questions than it answered. If you want to learn more of the technical/theoretical stuff, try the book 'Real World Color Management' by Fraser, Murphy & Bunting. The bottom line answer is one embedded profile and it's used by the CMS to render colors similarly on other devices that have their own profiles.

I'll hae to think about what use my monitor profile would be to anyone but me.

You got it. Your monitor profile is only useful to render colors on your monitor using the embedded profiles as a source for conversion. That's why sRGB was invented, it's a general purpose characterization of the average Windows monitor. The problem is, very few people adjust gamma or even know how their monitor is color balanced, plus monitors vary, windows color palettes vary... everything varies. With sRGB its usually possible to render a pleasing image on lots of monitors but don't expect them to match.

I hope this is helpful to you.