3.2. Antialias

3.2.1. 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.[12] 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.[13]

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.

3.2.2. Activating the filter

You can find this filter through FiltersEnhanceAntialias.

3.2.3. Examples

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

Original image (zoom 16:1)

Antialias applied (zoom 16:1)