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

1 Synopsis

scalex [-k 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 fast implementation of the Scale effects is used. It imposes some limitations of the type of the image usable. Specifically :

Only the pixel sizes of 1, 2 and 4 bytes are supported. If the image has another pixel size it's automatically converted.
The width of the image must be an exact multiplier of 8 bytes. If the image has an odd width the conversion fails.

3 Options

-k N, --scale N

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