[jfdavis58]

Introduction

Contrary to what the box cover, the saleman and the advertising hype state: "matching of monitor and print images", color management doesn't do that; it (purportedly) does 'accurate' and 'consistant'.

Accurate is easy to understand: red, blue and green are actually shown as red, blue and green. Consistent or consistency is a dumbing down of a far more important concept: continuity. Continuity from Newtonian Calculus. If you are math educated you might have some exposure to continuity. Basically when using real numbers, if you draw or imagine a line (defined as a function of one real number), then you can always find a part of the line (in the numbers) no matter the size (length) of the line; it's continuous. Try it: what number is halfway from zero to one--1/2. then from zero to 1/2:1/4. From zero to 1/4:1/8. How far can you go before you run out of numbers? {answer: you never run out of numbers!; you may run out of patience!!}

Continuity also has a second component, often overlooked or misunderstood, i.e.it's 'well-behaved'. If we expand our line analogy to a surface, continuity says we can also find the surface no matter how small we subdivided the numbers AND that in a region around our little chunk of surface, both the chunk and the remaining surface have the same properties and characteristics--it's well behaved.

For color management lets consider a well used CRT monitor. Experience tells one that sometimes one or more of the color guns in the picture tube might be weaker than the other two. Let's make the red gun weakest at about 85% of maximum intensity. Blue and green (for this example) will run at 92 and 94% of their maximum. Calibrating and profiling this monitor will cause all guns to work, to output at about 85% of total capacity, even though green and blue have greater remaining ability. While this condition may not produce the most vibrant reds, blues or greens, the output will be predictably accurate and consistant across the available range.

It actually turns out that accuracy is less important than consistency. The eye/brain will adapt for less than accurate colors as long as the tone is neutral and the colors are consistent with each other in the photograph and reasonably consistent to known perceptions and experiences of real life.

A careful reader will not the progression from one to two dimensions in the line and surface analogies. Logically, this expands to a 'space' in three dimensions or three variables. Consistency has at least the same importance, and perhaps more in the space analogy. Color spaces are defined as 3 variable spaces-red, blue and green being the three axis.

The typical (Pentax) dSLR can create both a RAW file and a JPEG file from the image data. Both have attached or assigned color space profiles. At a minimum this colorspace data contains a white point definition and three color response curves(red, blue, green). The RAW file's colorspace data is meaningful only to the RAW to RGB converter--specifically the color management module (CMM) in the RAW converter, e.g. Pentax Photolab, Photoshop Camera RAW plugin, etc. These converters will generate an RGB file with an appropriate working colorspace tag.


Naming the Spaces

In camera JPEG generation is limited to two working space tags: sRGB and aRGB. Ultimately either can be used to good effect but their selection is intimately tied to the final destination of the image. A computer based RAW converter often has much greater flexibility, both in terms of input parameters and in output control. Here it's common to have several output working spaces and tags; Photoshop for instance has ProPhotoRGB and ColorMatchRGB output tags/spaces.

Here are some of the necessary specifics of working colorspaces /tags:

sRGB
sRGB is the de-facto web (internet) standard colorspace. Few web browsers contain a fully compliant CMM; they expect color graphics to be in the sRGB colorspace-with or without the appropriate tag. Many if not all consumer level photo finishing labs (WalMart, Walgreens, Sams Club, Costco, and most 'mom & pop's') also expect digital input files to be sRGB colorspaced and hopefully sRGB tagged. Of particular note here is Jasc's Paintshop software. It's sRGB only, with a twist: if you ask for or submit anything aRGB or otherwise (than sRGB) tagged, the image will be output unspaced/untagged.

aRGB
This is Adobe Systems proprietary space. Adobe is a leader in press and pre-press equipment and software manufacturing. Adobe aRGB space is designed with CMYK printing as the final output and aRGB colorspace takes greater advantage of some greens and yellows availiable to slick magazine and book publication.

There are some regular users who claim a greater range of color is obtained from their home
((s-)RGB/CMYK) printers when the input file is aRGB spaced and tagged (and the printer is custom profiled and using same). This is a YMMV situation with pitfalls that I'll discuss when I expound on rendering intents.

ProPhoto
ProPhoto is an extremely wide ranging colorspace, allegedly designed by/for photographers. While you don't actually get any greater number of colors, you do get a greater range. Unfortunately there is no hardware that can output this range. What you see on the monitor is a cheap approximation. Certain special situations can cause severe image degradation--again something to be further discussed in rendering intent. This space most nearly mimics the gamut of the human eye range of reception.

Colormatch
A colorspace from Apple and Macintosh computers. The Mac is generally considered the best professional photographers editing platform. Many pro's like this particular color space for specific image content: skin and faces being the most notable. The total number of colors is exactly the same as all other color spaces, iIt's range of color falls somewhere between sRGB and aRGB---all much less than ProPhoto.

There are several other working spaces and profiles/tags. They are of and for limited and special uses; notably the emulation of specific film types like echtachrome slide film.

There are some special warnings about colorspace conversion: one often hears that going from a larger space to a smaller space is desired and that there is a potential for the loss of data and colors shifting. Let me clarify: there is always a loss of data and always some (hopefully small) color shifting when making a colorspace conversion; the potential is that it may be visually detectable. In the absence of an ability to convert from the original RAW file directly into a desired working space, the notion of converting colorspace from larger to smaller minimizes the aforementioned losses and color shifts, only when the large to small space difference is small and the affected colors are insignificant. Again, more on this will be found in the rendering intent material.


Monitor Calibration and Profiling

The actual details of procedure are being left to the individual Profiling Software/Hardware manufacturers; here I summarize what is being accomplished.

During calibration of a monitor the user will adjust the individual colors to acheive a neutral gray, As a means of transitioning from calibrating to profiling, the brightness and contrast settings are manipulated from minimum to maximum, perhaps while being measured by the screen device (spectrophotometer-the wand or hockey puck thingy). Transitioning to Profiling is complete with contrast set at or near maximum and brightness set for comfortable viewing in the typical viewing area.

Profiling accumulates the contrast and brightness data and the data from the screen response to a series of standard color swatches. Calculations ensue and a profile is prepared. The user may be asked to name the profile.

Just after the profile is calculated but before it is saved one special operation should be performed. The profile white balance should be adjusted to the room ambient lighting. Most often the user completely ignores or mis-performs this step. In the case with my older Monaco spectrophotometer device, I simply turn the 'puck' to face it's measuring aperture at the ambient light, click read or proceed or some such and let the software do it's thing.

Older monitors had two presets near 5000K and 6500K; get a newer monitor if possible. You need to be able to set any value from about 3300K (tungsten/incandescents) to 7000K(cool white fluorescents). Ott lights are about 4800-4900. Fluorescent lights can often have the color temperature stamped on the end. Sunlight is 5000-5500K but dependent on reflective surfaces.

I know this final step is difficult to understand and perform; but it is easy to determine when done properly.
Sit and edit a series of photographs. If after 30-40 minutes you are rubbing your eyes or perhaps have a low on the forehead headache, it's probably set wrong. This is eye strain, not simple fatigue. Find a photo with some pastel colors. Edit and have printed. If it's off in those soft colors, you need to redo the profile!

Once you have a profile (right or wrong) it must be installed at some convenient time. The commercial software should have installed a gamma loader. You should remove Adobe Loader; drag it to another file and hide it! At power ON bootstrap/start-up the gamma loader will inform the video hardware/software of the file name you supplied and the profile will be loaded. Other than to replace the profile as the monitor ages or room lighting changes, there is ABSOLUTELY NOTHING for the user to do with tis profile. Don't touch it, don't load it, don't move it, don't soft-proof with it! Just like the advise to never touch any of the monitors manual controls for contrast, brightness or color intensity and hue, DON'T MESS WITH THE PROFILE!


Summary of settings

From the camera JPEGs with an sRGB tag.
From the cameras RAWs get a sRGB spaced and tagged RGB in the converter (Camera RAW plugin); saved with profile tag

Set the Photoshop color settings dialog to North American General Purpose Defaults.
NOTE: I like to be told of mismatches: I set the policies box to 'preserve all file tag types (the edit fields)and check all the check boxes to enable notifications. This changes the name of the preset to Custom. One could save this preset if inclined.

The net effect is:
start with sRGB tagged RGB files,
edit sRGB tagged RGB files and
save sRGB tagged RGB files (JPEG,PSD or TIF).

I don't care how things 'appear' in non-color managed applications--they will turn out right if printed by typical commercial outsources or on my profiled printer.

One important setting in the color settings dialog is the rendering intent (intent in the conversion options sub-box).


Rendering intent

The conversion of an image file from one space/profile to another is inevitable. It's done when converting a RAW data set, again when the file is sent to the monitor and again when it's printed. You may disregard popular advise and need to do it to change working spaces.

So, How does it work?

The profile file contains the working data of a mathematical formula (actually three functions). The color management module takes that date, builds the equations and with the image data as input to the functions variables calculates a new set of data in the output space; pixel by pixel, color by color. There is one computational detail: input files and input profiles convert to something called profile connection space. Output files and output profiles convert from profile connection space to output space. Profile connection space (PCS) is an intermediary standard color space.

And it all works fine except when the color spaces span different ranges; which is almost always!

It's generally pretty hard to imagine in 3 dimensions so let's use an analogy. Carnivals and circus or state fair midways often have balloon vendors. You may have seen some balloons with an animal figure balloon inside a transparent regular round or pear shaped balloon. That's like a small color space and a larger color space. All the air in the figure ballon is also inside the outer regular balloon and the same is true with colorspaces. But what about the air between the figure balloon and the outer regular balloon? How do I push this air into the figure balloon and keep the same figure. Or back in the digitals photo world, what do I do with the colors in the larger space that aren't in the smaller space?

RENDERING INTENT!

There are four rendering intent rule sets: Perceptual, Saturation, Relative Colorimetric and Absolute Colorimetric. Perceptual and Relative Colorimetric are of particular interest to photographers--all are of interest to general graphics artists. This is a field worthy of intense study!

Perceptual rendering shifts all colors to maintain relationships. R-Colorimetric shifts to main constant hue. As for the colors that are in the larger but not in the smaller space, they all end up on the surface of the color space-a place known as the surface of saturation. There are to put it simply, no rules to successfully move the out of space colors into the space (you may hear of this as out of gamut colors...)

So what, you say! Here's the problem: color spaces are not smooth and regular, they are not elastic balloons. In L-a-b space diagrams--the most common visual presentation of color spaces--color space looks something like a beheaded, de-flippered and beat-up whale. Mathematically the term 'non-linear' applies: aside from skewing the out of gamut colors, in gamut colors don't always move nice and smooth to a new location.

Conclusion

The good thing is that digital photography is not all that different from film photography. In some sense all the new problems are just the old problems with new names. It's never been a perfect medium. Just like film, digital images with high levels of extreme saturation cause enormous problems.

And now you know, so google some names: Bruce Fraser-especially for color management, he will lead you to several others in the field (notably Rodney something (sorry forgot the name)-the Digital Dog, Clark of Clark Vision, the Imatest fellow(sorry again)). Dan Margulis if you want to eat, sleep and play with color-beware: nightmares!. Katrin Eisman, Lee Varis for skin (and a bunch of CMYK tricks to make it 'perfect'). Kevin Ames for expensive skin (and how to sell it legitimately). Harald Johnson if you want to extend CM to printing at home and other places on a professional level.

[nystateofmind27]

John, thanks for the indepth explanation of how colors actually work but unfortunately I can't see how to apply it to the practical problem at hand.

What is causing my mismatch between Photoshop and the other apps? Is it that Photoshop has its own color management? If so, who do i trust?

[jfdavis58]

Photoshop!

But then ...

This other app is mS Office Picture manager?

Can you send a sample photo?

John, thanks for the indepth explanation of how colors actually work but unfortunately I can't see how to apply it to the practical problem at hand.

What is causing my mismatch between Photoshop and the other apps? Is it that Photoshop has its own color management? If so, who do i trust?

[nystateofmind27]

Photoshop!

But then ...

This other app is mS Office Picture manager?

Can you send a sample photo?

http://www.njee.com/temp/color/color.jpg

[nystateofmind27]

Update: I installed Corel Paint Shop Pro and Photoshop Elements. Same darn problem. Elements renders the same as Photoshop, and Corel renders like Picasa and other basic photo viewers.

See comparison:
http://www.njee.com/temp/color/elementsVScorel.jpg


Edit:
I removed Photoshop and Elements, restarted and re-installed Elements only. Same result.

[nystateofmind27]

OK, new development. I've been playing around with Corel Paint Shop and i noticed it has a feature called Color Management. If i Enable Color Management, colors are rendered as in Photoshop, and if I disable it, they look like the other photo programs.

[jfdavis58]

So; getting some confidence in it/how it works/etc? Or still troubled?

What is/are your computer/operating system?

OK, new development. I've been playing around with Corel Paint Shop and i noticed it has a feature called Color Management. If i Enable Color Management, colors are rendered as in Photoshop, and if I disable it, they look like the other photo programs.

[nystateofmind27]

So; getting some confidence in it/how it works/etc? Or still troubled?

What is/are your computer/operating system?

John,

No, i'm still completely clueless. If i PP a photo in lightroom or photoshop to look to my liking then view it in Picasa (my favorite photo browser) the photo looks nothing like what it did when i processed it.

I narrowed it down to it being the issue of color management. Any idea how i should configure color management properly?


I'm using Windows XP Pro and i have pretty much every major photo editing software at my disposal.


Can we start from scratch? What would someone do to ensure proper color management. I have windows xp, the photo editing software, and a Spyder2PRO.


Thanks,
Peter

[jeffkrol]

Introduction

Contrary to what the box cover, the saleman and the advertising hype state: "matching of monitor and print images", color management doesn't do that; it (purportedly) does 'accurate' and 'consistant'.

(BIG SNIP, don't really need to repeat the whole thing)

And now you know, so google some names: Bruce Fraser-especially for color management, he will lead you to several others in the field (notably Rodney something (sorry forgot the name)-the Digital Dog, Clark of Clark Vision, the Imatest fellow(sorry again)). Dan Margulis if you want to eat, sleep and play with color-beware: nightmares!. Katrin Eisman, Lee Varis for skin (and a bunch of CMYK tricks to make it 'perfect'). Kevin Ames for expensive skin (and how to sell it legitimately). Harald Johnson if you want to extend CM to printing at home and other places on a professional level.

you forgot to mention "imaginary colors' and didn't mention
Bruce Lindbloom.........
Welcome to Bruce Lindbloom's Web Site
Or color correction via eyedropper (where even the colorblind can be the best)
Norman Koran=Imatest.
Norman Koren photography: images and tutorials
Andrew Rodney=digitaldog
Digital Dog :: Main
And for real fun go to Corel newsgroups and look up David Milisock
Professional Support for the CorelDRAW Graphics Suite - CorelDRAW.com
That man is a hoot.............
quote.......
Curious...does this apply to creating media profiles (including ICC creation) using spectrophotometers and such? I'm looking for some training in this regard, but have been told it's best done hands-on.


To answer your question in a short manner yes.

As far as hands on I would agree but this is where it gets just on the far side of interesting. If what you want is to make profiles for your output device and print it is not too bad. Figure about $3,000 for profiles creating and editing software and about $1,500 for a spectrophotometer. Another method would be to research a RIP that contains the profile creating software within, make sure you price it with a spectrophotometer. An example would be the Onyx poster shop or production house, look out for your wallet. Wasatch is another product with a decent low cost product about $1,000 without the spectrophotometer.

Now for self training, if you're a superior type individual in terms of your technical ability, figure about 80 hours of the most boring reading you've ever had and about $2,000 in materials and about 160 hours of test printing. You will at the end be able to make profiles and YOU will have an understanding of what you're doing. A few hundred bucks on consultation could help smooth this out and reduce the waste in training materials.

You could spend about $2,000 to get a professional in to set you up, unfortunately most of them cannot find their ass with both hands and a GPS. At the end you most likely will end up with profiles of lesser quality and YOU will have learned little.
....................

[jfdavis58]

Only so much fits in a peanut shell.

Bruce Lindbloom seems far to esoteric for most tastes. All those damn equations and even a seasoned engineer gets crossed-eyed. But then some of his test images and that 64million color thing is almost too much fun to play with to ignore.

I got a pro version of Imatest-those early pics of Koran are a hoot. Mostly though, he is just too busy to reach through e-mail or even the phone. His real skill is in lens system testing not color management-GamutVision leaves much to be desired--way to personalized and far too much engineer-speak when compared to something like ColorThink (where even the entry level app is intuitive for those left-brain types). I did de-compile Imatest and check all his equations and coding-some pretty cool stuff there.

Thought I mentioned Digital Dog; much of his stuff, lately, cost way too much money---hey, he'll set you up for just a couple hundred dollars. But what happens when the paper or the ink runs out--or the monitor bites the dust?

I stopped chasing PaintShop a long time ago. Too many parents, tube weirdness and no real color management. Maybe I should go and check the forums there; perhaps Coral has been good for them. I (think I) recall, vaguely the Milisock name--where is he from?

you forgot to mention "imaginary colors' and didn't mention
Bruce Lindbloom.........
Welcome to Bruce Lindbloom's Web Site
Or color correction via eyedropper (where even the colorblind can be the best)
Norman Koran=Imatest.
Norman Koren photography: images and tutorials
Andrew Rodney=digitaldog
Digital Dog :: Main
And for real fun go to Corel newsgroups and look up David Milisock
Professional Support for the CorelDRAW Graphics Suite - CorelDRAW.com
That man is a hoot.............
quote.......
Curious...does this apply to creating media profiles (including ICC creation) using spectrophotometers and such? I'm looking for some training in this regard, but have been told it's best done hands-on.


To answer your question in a short manner yes.

As far as hands on I would agree but this is where it gets just on the far side of interesting. If what you want is to make profiles for your output device and print it is not too bad. Figure about $3,000 for profiles creating and editing software and about $1,500 for a spectrophotometer. Another method would be to research a RIP that contains the profile creating software within, make sure you price it with a spectrophotometer. An example would be the Onyx poster shop or production house, look out for your wallet. Wasatch is another product with a decent low cost product about $1,000 without the spectrophotometer.

Now for self training, if you're a superior type individual in terms of your technical ability, figure about 80 hours of the most boring reading you've ever had and about $2,000 in materials and about 160 hours of test printing. You will at the end be able to make profiles and YOU will have an understanding of what you're doing. A few hundred bucks on consultation could help smooth this out and reduce the waste in training materials.

You could spend about $2,000 to get a professional in to set you up, unfortunately most of them cannot find their ass with both hands and a GPS. At the end you most likely will end up with profiles of lesser quality and YOU will have learned little.
....................

[jfdavis58]

Smaller peanut shell version, hmmm. well, what the hey!


You need to color manage an image for accurate color and consistant display and editing. It's never going to be a perfect match from device to device, but we want to keep shifts and data loss to a minimum.


Do the profile for the monitor again; or at least re-read all the instructions and assure yourself that you did every step (correctly). This should (have) put a monitor profile down in here: C:\Windows\System32\spool\drivers\color\driver. You probably named the profile.

When you installed the profiling software, it should have installed the gamma loader. When you installed any version of Photoshop or Elements (of recent vintage) it installed the Adobe gamma loader. The shortcut that causes Adobe Gamma Loader to run will be in one of the Startup folders. Find it, hide it in any folder somewhere different than the path along where it was was located.

Reboot from power off (Restart). Your profile should be loaded to your video card/hardware/software. Right-click on some empty desktop real estate, click the Properties menu item. This will bring up the Display Properties dialog. Click the Settings tab and the Advanced button. On the dialog that appears click the Color Management tab. Viola, your monitor profile on the top of the list-the default!

Enjoy an adult beverage!


Close everything, launch Photoshop. If you spent a lot of time messing with various settings and features in Photoshop, you might want to flush the preference file. The three finger salute that does this is hold down ctrl+alt+shift as soon as you launch the application. All user customized presets will be lost! All palettes and workspace set-ups will be set to fresh from the box defaults. Color management will be set to it's lowest default level.

When the app finishes all it's start-up gyrations Go to the Edit menu, Color settings item and open the dialog. Scroll the top list to North American general Purpose Defaults and select it. Click any of those boxes I mentioned in the long reply for features you want to add. Close the dialog.



If you convert RAW to JPEG in camera set the camera color space to sRGB. If you use Camera RAW Plug-in, set the output color space to sRGB before you move the file into Photoshop.

Take and download some images to a convient place on your harddrive. Open them in Photoshop or Camera RAW.


You're color managed!

When you save the edited file make sure the 'include profile' button is check and the profile indicated is sRGB...

If another app has color managment-like PaintShop-turn it on per their instructions. If an app doesn't color manage expect some color shift. It should be (relatively) small. You will most likely notice color shift of a large magnitude with files that are tagged aRGB or others in those non-CM apps. In Photoshop (with CM on per above with the notification boxes checked) you will get a warning! And some options. Either open it with the existing profile or open it after converting to your working space profile. All those nasty things in the long post will apply. You avoid data losses by not using non-CM apps to edit the file!

John,

No, i'm still completely clueless. If i PP a photo in lightroom or photoshop to look to my liking then view it in Picasa (my favorite photo browser) the photo looks nothing like what it did when i processed it.

I narrowed it down to it being the issue of color management. Any idea how i should configure color management properly?


I'm using Windows XP Pro and i have pretty much every major photo editing software at my disposal.


Can we start from scratch? What would someone do to ensure proper color management. I have windows xp, the photo editing software, and a Spyder2PRO.


Thanks,
Peter

[nystateofmind27]

John, thanks again. I just about gave up on my PC and stepped over to my laptop and check out the results:

Laptop is a quality dell xps, color calibrated with spyder2pro as well, profile is set automatically on each start-up by the spyder2pro software and adobe gamma is Disabled. I should say that i'm using adobe CS2 (color management enabled) and Windows Vista on the laptop.

I recreated the same situation that I have on the PC and guess what... ALL PROGRAMS DISPLAY THE PHOTO EXACTLY THE SAME. There is none or virtually no difference between a photo rendering in Office Manager, Picasa, or PHOTOSHOP.


I'm starting to think the problem lies somewhere with the PC video card or other setting?


-Peter

[Captain]

I just installed the pentax photo browser and Labrotory.
Will they do the same as photo shop?

Mike

[jfdavis58]

Yes and NO. PPB and PPL will allow you to see and convert RAW pentax files. Editing is not really possible.

I just installed the pentax photo browser and Labrotory.
Will they do the same as photo shop?

Mike

[jeffkrol]

Only so much fits in a peanut shell.

Bruce Lindbloom seems far to esoteric for most tastes. All those damn equations and even a seasoned engineer gets crossed-eyed. But then some of his test images and that 64million color thing is almost too much fun to play with to ignore.

Yep way beyond me but a fun read.....

I did de-compile Imatest and check all his equations and coding-some pretty cool stuff there.

That's cool. Some don't trust his "results" but as with all things it's more in the understanding
and if you can relate it to the real world. Good to see someone keeping an eye on him.

Thought I mentioned Digital Dog; much of his stuff, lately, cost way too much money---hey, he'll set you up for just a couple hundred dollars. But what happens when the paper or the ink runs out--or the monitor bites the dust?

The main problem w/ all "at home" color management. Constant tweaking.

I stopped chasing PaintShop a long time ago. Too many parents, tube weirdness and no real color management. Maybe I should go and check the forums there; perhaps Coral has been good for them. I (think I) recall, vaguely the Milisock name--where is he from?

Actually I was referring to Corel Photopaint not PSP... an interface I never warmed to. And lack of 16bit support at the time.
As to Milisock, he "just appearred", somewhere around ver 12 of CorelDraw. and some real "lively" CM discussions ensued.. NOT for the weak of heart.... apparently as a consultant on CM and to fix the busted parts. Mostly CMYK and pre-press related I believe and therefore not totally relevent to us.... ????
COREL DRAW SUITE has been my poor mans Adobe CS for ages but Photopaint has seen hard times. Kind of like Pentax no?