Справочник Пользователя для Adobe photoshop cs2
229
ADOBE PHOTOSHOP CS2
User Guide
These guidelines apply to converting images to and from Grayscale mode:
•
You can convert both Bitmap mode and color images to grayscale.
•
To convert a color image to a high-quality grayscale image, Photoshop discards all color information in the
original image. The gray levels (shades) of the converted pixels represent the luminosity of the original pixels.
original image. The gray levels (shades) of the converted pixels represent the luminosity of the original pixels.
You can mix information from the color channels to create a custom grayscale channel by using the Channel Mixer
command.
command.
•
When converting from grayscale to RGB, the color values for a pixel are based on its previous gray value. A
grayscale image can also be converted to a CMYK image (for creating process-color quadtones without converting
to Duotone mode) or to a Lab color image.
grayscale image can also be converted to a CMYK image (for creating process-color quadtones without converting
to Duotone mode) or to a Lab color image.
See also
Duotone mode
Duotone mode creates monotone, duotone (two-color), tritone (three-color), and quadtone (four-color) grayscale
images using one to four custom inks.
images using one to four custom inks.
See also
Indexed Color mode
Indexed Color mode produces 8-bit image files with at most 256 colors. When converting to indexed color,
Photoshop builds a color lookup table (CLUT), which stores and indexes the colors in the image. If a color in the
original image does not appear in the table, the program chooses the closest one or uses dithering to simulate the
color using available colors.
Photoshop builds a color lookup table (CLUT), which stores and indexes the colors in the image. If a color in the
original image does not appear in the table, the program chooses the closest one or uses dithering to simulate the
color using available colors.
Because the palette of colors is limited, indexed color can reduce file size yet maintain the visual quality needed for
multimedia presentations, web pages, and the like. Limited editing is available in this mode. For extensive editing,
you should convert temporarily to RGB mode. Indexed color files can be saved in Photoshop, BMP, GIF, Photoshop
EPS, Large Document Format (PSB), PCX, Photoshop PDF, Photoshop Raw, Photoshop 2.0, PICT, PNG, Targa, or
TIFF formats.
multimedia presentations, web pages, and the like. Limited editing is available in this mode. For extensive editing,
you should convert temporarily to RGB mode. Indexed color files can be saved in Photoshop, BMP, GIF, Photoshop
EPS, Large Document Format (PSB), PCX, Photoshop PDF, Photoshop Raw, Photoshop 2.0, PICT, PNG, Targa, or
TIFF formats.
Multichannel mode
Multichannel mode uses 256 levels of gray in each channel. Multichannel images are useful for specialized printing.
Multichannel mode images can be saved in Photoshop, Photoshop 2.0, Photoshop Raw, or Photoshop DCS 2.0
format.
Multichannel mode images can be saved in Photoshop, Photoshop 2.0, Photoshop Raw, or Photoshop DCS 2.0
format.
These guidelines apply to converting images to Multichannel mode:
•
Color channels in the original image become spot color channels in the converted image.
•
When you convert a color image to a multichannel image, the new grayscale information is based on the color
values of the pixels in each channel.
values of the pixels in each channel.
•
Converting a CMYK image to Multichannel mode creates cyan, magenta, yellow, and black spot channels.
•
Converting an RGB image to Multichannel mode creates cyan, magenta, and yellow spot channels.