Practical Color Management: Eddie Tapp on Digital Photography

CHAPTER 2: Understanding Key Color Management Concepts

18

Rendering intents determine how the

color of one device converts to another

device. Depending on the color and

tonality in the two di erent color spaces,

the di erences can range from minimal to

fairly dramatic. When converting from one

space, such as RGB, to another, such as

CMYK, we go though the PCS (discussed

in “PCS Source and Destination,” earlier

in this chapter). There are four di erent

rendering intents that ICC pro les may

have for resolving color di erences:

perceptual, saturation, relative

colorimetric, and absolute colorimetric.

The images here illustrate the di erences

among the four di erent rendering

intents. The e ects of the di erent

intents have been exaggerated so

that they are easier to distinguish

visually. Even with the exaggerated

colors, it is still sometimes di cult

to see the subtle di erences.

Original image

Rendering

Intents

As you’ve learned, di erent devices have di erent size

gamuts. When you convert from one color space to another,

the colors and tones need to be changed to  t into the new

color space. The rendering intent is the strategy for resolving

the di erences in color space.

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Perceptual

This intent (sometimes referred to

as photographic) tries to preserve

the overall color appearance by

changing the colors of the source

image to  t into the destination space.

It sacri ces accuracy to produce

a more visually pleasing image.

This intent is very useful when the

source has a wide gamut and the

destination has a small gamut.

Saturation

This intent tries to produce the most

vibrant color by pushing the color of

the source image out as far into the

destination space as possible. It is not

used much by photographers but is

often used for business graphics to

achieve bold color in presentations.

Relative colorimetric

This intent is used when color

accuracy is the most important

concern and is the default rendering

intent in the more recent versions of

Photoshop. It works very well when

the source and destination pro les

have similar gamuts. If the gamuts

of two devices are too di erent from

one another, the more saturated

color may be clipped or minimized.

Absolute colorimetric

This intent is usually used for proo ng

when trying to simulate one device

on another. It is similar to relative

colorimetric, except all the color

adjustments are based on the white

point. Unlike relative colorimetric,

absolute colorimetric shows the white

of the source pro le. In some cases,

this intent can create an undesirable

color cast if used as a default.

Relative colorimetric

Saturation

Perceptual

Absolute colorimetric

Rendering Intents

19

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