each pixels color. Because monitors are RGB devices, they cant
display CMYK colors directly. However, Canvas attempts to display
CMYK images as they will appear when printed.
LAB Color image mode
The Commission Internationale dEclairage (CIE) developed the
LAB Color mode as an international color standard to overcome the
device dependency of the RGB and CMYK modes. In a LAB Color
mode image in Canvas, each pixel has one lightness and two color
components. The Lightness (L) channel has 256 levels of intensity.
The two color channels, labeled A and B, provide a color range from
red to green and yellow to blue, respectively.
Some companies sell collections of images in LAB Color mode.
Editing LAB Color mode images with some filters or painting tools
can have interesting and unpredictable effects.
Duotone image mode
In traditional graphics arts reproduction, a duotone is a grayscale
image printed with black and an additional color. Canvas lets you
create duotone images, as well as monotone, tritone, and quad-
tone images (printed with one, three, or four colors, respectively).
Printing images as duotones can add interest and increase the tonal
range reproduced from grayscale photographs, without the additional
expense of printing full-color images. The duotone effect can be sub-
tle or striking, depending on the color used and the amount added to
the image. In any case, the additional colors are used to reproduce the
gray values in the image, rather than to reproduce specific colors.
To create a monotone, duotone, tritone, or quadtone in Canvas, you
must convert a Grayscale image to Duotone mode. Unlike other
image modes, once an image is converted to Duotone mode, you can-
not work with individual image channels. Instead, you can adjust
curves for each color channel in the Duotone Options dialog box.
Note: In this section, the term Duotone refers to the Duotone image
mode, not just to images printed with two inks. In Duotone mode, an
image can be printed as a monotone, duotone, tritone, or quadtone.
To create a Duotone image
1
Select paint object and choose Image > Mode > Grayscale to
convert to Grayscale mode. Click OK when Canvas asks to discard
color information. Then choose Image > Mode > Duotone.