4.2. Antialias

4.2.1. Overview

This filter reduces alias effects (see Antialiasing) using the Scale3X edge-extrapolation algorithm.

Scale3X is derived from Scale2X, which is a graphics effect to increase the size of small bitmaps guessing the missing pixels without interpolating pixels and blurring the images.[11] Scale2X was originally developed to improve the quality of old Arcade and PC games with a low video resolution played with video hardware like TVs, Arcade monitors, PC monitors and LCD screens.[12]

The Antialias filter works as follows:

For every pixel,

  1. the filter expands the original pixel in 9 (3x3) new pixels according to the Scale3X algorithm, using the colors of the pixel and its 8 adjacent pixels (extrapolation);

  2. then the filter subsamples the new pixels to a weighted average pixel.

4.2.2. Activating the filter

You can find this filter through Filters → Enhance → Antialias.

4.2.3. Examples

The following examples illustrate the effect on some patterns. The small squares are one pixel in size (zoom 16:1).

4.2. Antialias - 图1

Original image (zoom 16:1)

4.2. Antialias - 图2

“Antialias” applied (zoom 16:1)

[11] [SCALE2X].

[12] [AdvanceMAME].