Scale a .PNG image using the reference implementation of the Scale effects

1 Synopsis

scalerx [-k N] [-w] [-r N] input.png output.png

2 Description

Scale2x, Scale3x and Scale4x are real-time graphics effects able to increase the size of small bitmaps guessing the missing pixels without blurring the images.

They were originally developed for the AdvanceMAME project in the year 2001 to improve the quality of old games running at low video resolutions.

The specification of the algorithm and more details are at:

http://scale2x.sourceforge.net

These command line tools read a .PNG file and write another image with the effects applied.

The reference implementation of the Scale effects is used.

3 Options

-k N, --scale N

Select the scale factor. Available values are 2, 3 and 4.

-w, --wrap

Compute the image border for a wraparound effect.

-r N

Select a specific revision of the Scale2x effect. The standard algorithm is 1. 0 is the normal scaling. 2 and 3 are alternative versions.