Simple difference in Photoshop grayscale, index, RGB, CMYK four mode

Grayscale mode : Simple point that grayscale mode is like Black-and-white photos, all colors are in different 256 shades of gray (so in grayscale mode to fill in other color color, the default will be associated with the gray color replacement fill!)

indexing mode : When doing Web pages, indexed color files are generally GIF format (saved in GIF format of the picture, will automatically turn into the index mode, you must turn to RGB mode to edit the picture), and RGB mode is JPG or PNG format.

RGB mode : is a color photo, all colors are red (R) Green (G) Blue (B) out of various colors. It is stored in three bytes (24 bits) in the computer, which is usually 24-bit true color.

CMYK mode : CMYK represents four kinds of colors used in printing, C for cyan, m for magenta, Y for yellow, and K for Black. Because in actual quotes, cyan, magenta, and yellow are hard to overlay to form real black, most of which is brown. Hence the introduction of k--black. The role of black is to strengthen the dark tone, deepen the dark color.

CMYK mode is the best printing mode, RGB mode, although many colors, but not fully printed out.

Using CMYK mode editing can avoid the loss of color, but the operation speed is very slow. Because: 1, even in the CMYK mode of work, Photoshop must also convert the CMYK mode to the display of the RGB mode used. 2, for the same image, RGB mode only need to handle three channels, and CMYK mode will need to handle four channels