5.10. Desaturate

By using the Desaturate command, you can convert all of the colors on the active layer to corresponding shades of gray. This differs from converting the image to grayscale in two respects. First, it only operates on the active layer and second, the colors on the layer are still RGB values with three components. This means that you can paint on the layer, or individual parts of it, using color at a later time.

[참고] 참고

This command only works on layers of RGB images. If the image is in Grayscale or Indexed mode, it can do nothing.

5.10.1. Activating the Command

You can get to this tools in several ways:

  • In the image menu through ToolsColor ToolsDesaturate… or ColorsDesaturate…,

  • by clicking on the tool icon in Toolbox, if this tool has been installed there.For this, please refer to 1.7절. “도구상자”.

5.10.2. Options

그림 14.176. The Desaturate option dialog

The Desaturate option dialog

Three options are available:

Choose shade of gray based on

Lightness

The graylevel will be calculated as

Lightness = ½ × (max(R,G,B) + min(R,G,B))
Luminosity

The graylevel will be calculated as

Luminosity = 0.21 × R + 0.72 × G + 0.07 × B
Average

The graylevel will be calculated as

Average Brightness = (R + G + B) ÷ 3

그림 14.177. Comparing the three options

Comparing the three options

원본 이미지

Comparing the three options

Lightness applied

Comparing the three options

Luminosity applied.

Comparing the three options

Average applied.