8.56. Posterize

8.56. Posterize
	8. The “Colors” Menu

8.56.1. Overview

图 16.222. Example for the “Posterize” filter

Original image

“Posterize” with 3 levels applied

This tool is designed to intelligently weigh the pixel colors of the selection or active layer and reduce the number of colors while maintaining a semblance of the original image characteristics.

8.56.2. Activating the Filter

This filter is found in the main menu under Colors → Posterize….

8.56.3. Options

图 16.223. Posterize filter dialog

Presets

“Presets” are a common feature for several Colors commands. You can find its description in 第 8.1.1 节 “Colors Common Features”.

Posterize Levels

Here, “level” means “number of colors per channel ”.

This slider and the input boxes with arrowheads allow you to set the number of levels (2-256) in each RGB channel that the tool uses to describe the active layer. The maximum total number of colors is the combination of these levels. A level to 3 will give 3³ = 27 colors.

Blending Options, Preview, Merge filter, Split view

These are common features described in 第 8.1.1 节 “Colors Common Features”.