Section 2.2. Device Profiles

2.1. Calibration Versus Profiling

In reality, calibrating and profiling is a partnership rather than a competition, but people frequently confuse these terms. Calibrating is like giving a device a fine tune-up, while profiling is describing the exact color gamut of the device in its already tuned-up condition.

Calibration refers to setting up a device in a centered state or known condition, where it can then yield the best performance within given parameters. For example, you might calibrate a device to a color temperature setting of 6500 degrees Kelvin and a gamma setting of 2.2 (don't worry, those settings will make sense after Chapter 4). Once you've established a few parameters, the tool to calibrate the monitor can position the color temperature and gamma for proper viewing during calibration.

Profiling is measuring the capabilities of a (calibrated) device and then saving this information in a file known as an ICC profile. The ICC profile is used as a color space that your file can be converted into in order to manage the color while you view an image on a properly calibrated display.

The term "profile" is also used to describe a combination of elements or characteristics. When using a film scanner, for instance, you can choose a profile of a specific film type such as Fuji or Kodak film, or even a look, such as a "portrait look" (less saturated) or "product look" (more saturated). These profiles are more specifically LUTs (lookup tables) that allow you to control the centering or color temperature of the scanner along with other properties such as gamma or contrast settings.

When shooting in the JPEG mode, a digital camera will allow you to set a Matrix that could include a color space (such as sRGB or Adobe RGB), saturation, contrast, and even sharpness settings. This too is a type of "LUT" profile, where the color space's sRGB or Adobe RGB are actually a color space profile embedded in the file from the camera's firmware. RAW profiles are embedded during processing and not in the camera.

Device calibration can be achieved using sophisticated tools or software that is packaged with the device. For instance, an ink-jet printer might include a utility that allows you to establish print head alignment and nozzle cleaning for calibration. A monitor or display is best calibrated using a device known as a colorimeter. In either case, there is always a "proper" way to calibrate a device, given a type of workflow or objective.

We'll get to that in Chapter 4, but for now, understand that calibration of a device goes hand in hand with creating an ICC profile of the device in its calibrated state. If results suddenly become inconsistent in a workflow, recalibrating a device will bring back the consistency.

Practical Color Management. Eddie Tapp on Digital Photography
Practical Color Management: Eddie Tapp on Digital Photography
ISBN: 0596527683
EAN: 2147483647
Year: 2006
Pages: 61

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