each pixel’s color. Because monitors are RGB devices, they can’t display CMYK colors directly. However, Canvas attempts to display CMYK images as they will appear when printed. LAB Color image mode The Commission Internationale d’Eclairage (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.
Canvas 8 Help: Painting and image-editing (43 of 46)                                                Page #629