Color workflow on a Mac

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Paramvir Singh
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Color workflow on a Mac

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What you need to get started

Getting started with virtual color proofing is easier than ever. Yesterday, virtual color proofing required many different hardware and software devices, constant intervention and fine tuning. Today, digital technology has refined the process to just a few key components and automated many steps in the workflow.


Mac OS X Tiger
With Mac OS X Tiger, and now Leopard (OSX 10.5x) it is faster, easier and more affordable than ever to achieve consistent color — a prerequisite for accurate virtual color proofing. Mac OS X Tiger takes a system-wide and always-on approach to color by integrating ColorSync, based on the International Color Consortium (ICC) standard for color management, into every phase of the workflow: capture, edit and output. This ensures that color accurately translates from one device to another across your entire workflow.

Apple Mac Pro
The foundation of your virtual color proofing platform, the Mac Pro provides the computational power to realize all of your creative ideas in any medium. With its 64-bit Dual-Core Intel Xeon processors and PCI Express architecture, it radically increases data bandwidth system-wide and introduces an all-new set of performance features never before seen on a desktop computer. The Mac Pro delivers the multitasking power you need to realize your ideas as fast as you can imagine them. Plus, you get all the power and ease of use of the Mac OS X operating system.

Apple Cinema Displays
Apple pioneered the move to LCD technology in 2001 with an award-winning line of all-digital, active-matrix, flat-panel displays and has since built the industry’s most innovative, elegant displays. Based on the industry’s best LCD technology, the Apple Cinema Display line delivers performance superior to that of any CRT-based display. Compared with other LCD monitors, the Apple line stands out in numerous ways: its wide-aspect design, DVI connector, integrated FireWire and USB ports, the ultrathin bezel, brushed-aluminum enclosure and VESA mountable and adjustable stand.

The Cinema Display’s total color gamut — number of viewable colors — is perceptibly larger than that of the CRT. You can use the Cinema Display in normally-lit settings — not darkened rooms — with little reduction in the dynamic range of colors being displayed.

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Brightness
When designing CRT displays, engineers must always make a trade-off between brightness and sharpness. If the CRT screen is made brighter, the text typically becomes less sharp. That’s because CRT technology is based on light-emitting phosphors. As a given phosphor glows brighter, it becomes harder to distinguish it from neighboring phosphors. The result is that adjacent pixels become less distinct and therefore less sharp.

Place an Apple Cinema Display side by side with a conventional CRT display and you’ll immediately notice that the Cinema Display’s colors appear more vivid and lifelike, because its total color gamut — number of viewable colors — is perceptibly larger than that of the CRT. The benefit of this larger apparent gamut is that you can use the Cinema Display in normally-lit settings — not darkened rooms — with little reduction in the dynamic range of colors being displayed (that is, without the colors becoming washed out).

Flat-panel displays turn each pixel on and off using transistors directly in the screen that activate the liquid crystal layer with electricity. This means an LCD can be made very bright without reducing the clarity of text or graphics. A key benefit of a bright screen is that it allows you to view fine details and subtle color differences even in well-lit office and home environments.

Contrast
Another benefit of increased brightness is better contrast ratio. Contrast ratio is the ratio between the whitest white and the blackest black on a display — its dynamic range. Because flat-panel displays are brighter, they can create brighter whites, thus instantly increasing the contrast ratio.

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Sharpness and Lack of Flicker
In a CRT, the energy from an electron beam hitting the phosphors creates light, which fades after the beam sweeps to other parts of the screen. The sharpness of a CRT is determined by the size of the area excited by the electron beam. To minimize the apparent flicker of the phosphor being excited and fading, a good CRT monitor refreshes each part of the screen at an extremely fast rate — 75 times a second or more.

At those speeds, however, it’s difficult to control the spot size of the electron beam and therefore to create a sharp transition between dark and light areas. So CRT engineers again face a trade-off: a high refresh rate and a sharp image are difficult to implement simultaneously at high resolutions.

Modern CRT displays with high refresh rates have minimized flickering, which is widely accepted to cause eyestrain and associated headaches. LCDs, however, offer an even greater advantage: They have no electron beam rapidly “painting” an image on the screen, line by line. Each and every pixel on an LCD turns on and off independently whenever needed. This means you can have consistent, sharp, flicker-free color for a stable view of your virtual proof.
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Re: Color workflow on a Mac

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The basics of virtual color proofing

Preparing your Apple Cinema Display
The first step in good virtual color proofing is verify what you see on your Apple Cinema Display — it’s the window into everything you do. This means that your display must be properly calibrated and profiled to ensure that what you see on screen matches what you and your clients will see in virtual proof and final output.


Mac OS X Tools for Display Calibration and Profiling
When you connect a display, let it warm up for about 30 minutes and turn off any energy savers that might dim or blank the screen. Your Macintosh will automatically query your display for industry-standard information. Based on this data, ColorSync automatically creates and assigns a factory display profile. This means every Mac running Mac OS X 10.3 (or later versions) can display color accurately without any effort on your part. For even better color results, consider calibrating and creating a custom profile for your particular display.

A calibration sequence makes sure the display behaves consistently before profiling. The display is told to produce a series of colors in sequence. Each color is measured to compare the requested color with the actual color displayed. The results are saved in the correct system location automatically.
Once your display is calibrated, you can create a custom ICC profile for it.
You can accomplish both of these steps using the Display Calibrator Assistant built into Mac OS X Tiger. Enhancements to the new Display Calibrator give you more control over customizing the color space profile of Apple displays.

Every Mac running Mac OS X 10.3 (or later versions) can display color accurately without any effort on your part. For even better color results, calibrate and create a custom profile for your display.
To use the Display Calibrator Assistant, go to System Preferences and select Displays. Click the Color tab and then the Calibrate button to view the Display Calibrator Assistant screen. Check the Expert Mode box. Click Continue.

The onscreen directions walk you through the calibration and profiling process. At the end, you can name and save a custom profile for your display.

You should calibrate and profile your display about once a month, because ambient conditions and the color on your display can change.

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Taking Good Calibration to the Next Level
For the ultimate in color accuracy, consider investing in a hardware device for calibrating and profiling your display such as the MonacoOPTIXxr hardware and software, the GretagMacbeth Eye-One Display, which works in conjunction with GretagMacbeth’s Eye-One Match software, or the Spyder2 ProStudio 2.0. MonacoOPTIX, a colorimeter, calibrates, and profiles your display by mimicking how the human eye sees the color on your display. The Eye-One Display is an affordable spectrophotometer that attaches to your monitor and measures and defines the color on your display. The Spyder2 PRO Studio includes a highly sensitive colorimeter that lets you easily calibrate all of your displays, including projection devices.


Onscreen help in both software packages guides you through the process of calibrating and profiling your display using hardware devices. The software offers predefined settings and automated processes if you don’t want to develop customized settings. Or experienced users can create their own custom settings for brightness, white point, and contrast using Advanced Mode. Once the profiling kit has calibrated your display and created a custom profile, Mac OS X makes your display’s custom profile accessible throughout your system to all of your applications.

Now, ask your clients to calibrate their displays so that they, too, can trust the color they’re viewing exactly matches your intent.

Get more information about solutions from GretagMacbeth, X-Rite, and ColorVision by Datacolor.

Embedding a Profile
Once you and your clients can mutually trust what you see on your displays, it’s time to “tag” your image or layout with an output device profile for the printer, proofer or other device. You can acquire this device profile from your commercial printer.

When you get the device profile, install it in /Library/ColorSync/Profiles and ask your clients to do the same. Essentially, tagging an image means that you’ve digitally embedded the color profile describing the output device into the image file. Once you’ve tagged the image, then you are actually viewing a soft proof virtual press printout of the final output, right on your screen.

Now you can easily create a virtual proof by converting the color in the source document or image to reflect the color capabilities specified by the profile of your output device. The following pages show steps to follow in both editing and imaging applications.

Aperture:

How to create a virtual color proof

Setup
1) Choose the menu Presets>Export Presets
2) Select the Add (+) button to create an Export Preset for the desired output device.
3) Pull down the ColorSync Profile menu to select the output device (destination color space) for the virtual color proof. The source color space is either the space assigned in camera or Aperture's internal high-dynamic color space, which is applied as necessary to preserve all color edits. Aperture automatically uses relative colorimetric as the rendering intent.
4) Click Okay.
Proofing
5) Choose View>Onscreen Proofing, then select the appropriate profile to proof against with View>Proofing Profile.
6) Export a version of the file by choosing File>Export Version and selecting the Export Preset you have configured.

Image

Adobe Photoshop:
How to create a virtual color proof

1) Choose the menu Image>Mode>Convert to Profile…
2) Pull down the Destination Space menu
3) Choose your output device profile
4) Next, under Conversion Options, choose Apple CMM
5) Choose an Intent. We recommend either Relative colorimetric or Absolute colorimetric, depending upon which best renders the color you want to print. You can preview both options in this menu box before making a decision.
Click Okay
6) Save the file with a new name and send to your client for review.
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Re: Color workflow on a Mac

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Download “Color Theory” (PDF) by John Paul Caponigro. This essay explains how you can sharpen your perception of color by properly understanding color theory.

Caponigro on Color
The Temperature of Color - Warm or Cool

An essential quality of color is temperature. Temperature can be used to attain a color balance, enhance spatial relationships within an image, and elicit psychological responses. Understanding and exploring the dynamics of temperature in color can benefit any visual artist.

There are physical characteristics of color linked to temperature. The color temperature of light (Kelvin degrees) is determined by measuring a black body radiator (an object heated so that it emits light). As the physical temperature of the object rises, color transitions from red (long wavelengths — low energy) to blue (short wavelengths — high energy) through ROYGBIV (red, orange, yellow, green, blue, indigo, violet). When it comes to light sources, physically, blue is warmer than red.

There are also psychological qualities of color linked to temperature. Psychologically, blue is cooler than red. These associative qualities of color with regard to temperature are almost universally accepted. This is due in large part to our physical environment — water is blue, plants are green, sunshine is yellow, fire is red.

Using the qualities of one sense (touch) to describe the qualities of another (sight) can be a tenuous affair and may lead to ambiguity and confusion. The more precise a language is the more useful it is. The language of HSL (hue, saturation, luminosity) is a very precise language. When using the language of HSL, hue values mark a position measured in degrees (0-360) on a color wheel.

0 red
30 orange
60 yellow
90 yellow green
120 green
150 blue green
180 cyan
210 green blue
240 blue
270 purple
300 magenta
330 blue red

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The line between 90 and 270 degrees divides the color wheel in two halves — warm colors (right) and cool colors (left). Two points on the color wheel can be considered absolutely warm (0) or cool (180). Moving any color towards or away from one of these points either warms or cools it.

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The colors in the image plotted on the Apple color picker.

Absolutely warm and cool colors can be found at 0 (red — no warmer color) and 180 (cyan — no cooler color) degrees. Determining whether one color is warmer or cooler than another can be measured by its proximities to these poles. A line between 90 (green yellow) and 270 degrees can be used to broadly demarcate warm colors from cool colors; colors on the right (towards red) are warm while colors on the left (towards cyan) are cool. The association of yellow with the sun, a warm light source, subtly skews the associative quality of warmth towards yellow (60) and away from blue; as a result, colors above the line between 0 and 180 tend to seem warmer than colors below it — i.e. while both are equally distant from red (0), orange (30) seems warmer than blue red (330).) While one color can be seen as warmer or cooler than another color, each color also has warm and cool components — there are warm yellows and cool yellows, warm blues and cool blues, etc. (Where numerical classifications of colors define hues very specifically — 1 degree per hue, 30 degree spread per linguistic color — linguistic specifications of colors — red, orange, yellow, etc. — define broad ranges of hues.) Defining the warm and cool endpoints of any linguistic color is useful at a coarse level of granularity but becomes increasingly subjective at a fine degree of granularity. At what point does blue become purple? At what point does blue become green?

It’s possible to describe the adjustment of hue simply in terms of warming and cooling.

Photographic color adjustment strategies rely on adjusting a balance in each of three complements.

R — C
G — M
B — Y

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An image with a color dynamic that is warm and cool, which uses both warm and cool variations of the two dominant hues.

Each set of complements has a warm and cool dynamic.

R (warm) — C (cool)
G (cool) — M (warm)
B (cool) — Y (warm)
These three complementary axes have different warm/cool dynamics with respect to the three color primaries - RGB.

red (warm red) — cyan (cool blue): warm/cool
green (cool green) — magenta (cool red): cool/cool
blue (warm blue) — yellow (warm green): warm/warm
You can make a field of color appear more dynamic, complex, and three-dimensional by preserving or introducing a variety of warm and cool components in it.

The temperature of color carries spatial associations with it. Warm colors tend to appear to be nearer than cool colors. Again this is universal. It can be overturned by many factors. Some factors are related to color — saturated colors appear nearer than desaturated colors or a progression from light to dark may be the primary element that establishes spatial hierarchy. Other factors are not related to color — for instance, placement and overlap in composition may be primary spatially, overriding color relationships.

Color balance, spatial proximity, association — these are just three of the uses of warm and cool color dynamics in images. Whether you are adjusting preexisting color relationships or creating new ones, having thoroughly explored the warm and cool dynamics of hue, you can apply that knowledge towards the realization and enhancement of your images.
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