Scale2x is real-time graphics effect able to increase the size of small bitmaps guessing the missing pixels without blurring the images.
It was originally developed for the AdvanceMAME project in the year 2001 to improve the quality of old games with a low video resolution. Derivative Scale3x and Scale4x effects which scale the image of 3x and 4x are also available.
 scale4x |
 scale2x |
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Scale2x is used in the following OpenSource projects:
- AdvanceMAME 2001/07
- xmame 2001/10
- ScummVM 2002/04
- Raine 2002/11
- Visual Boy Advance 2002/11
- FB Alpha 2002/12
- CottAGE 2002/12
- Pygame 2002/12
- Psx Emulation Open Source 2003/01
- Exult 2003/03
- DosBox 2003/04
- GnGeo 2003/05
- Jump'n'Bump 2003/07
- PrBoom 2003/07
- Sarien 2003/7 (CVS)
- MAMEPlus 2003/08
- MAMEoX 2003/08
- WinUAE 2003/08
- TI-99/Sim 2003/08
- Fuse 2003/09
- VICE 2003/10
- VirtuaNES 2003/10
- GEST 2003/10
- Nestopia 2003/11
- Open MSX 2004/01
- FCE Ultra 2004/03
- Gens Plus! 2004/09
- olafnes 2004/12
- Osmose 2005/03
- UFO 2000 2005/08
- Unreal Speccy 2005/09
- CloneKeen 2005/10
- ZBoy
It is also used in some closed source projects (which use rewritten implementations due the license restrictions) :
- Nebula
- Kawaks (with the name KScale)
- Pocket RPG Maker 2005/10
If you know other projects which use the Scale2x effect please send an email and I will add them to the list.
Scale2x has also a SourceForge page and a FreshMeat page. It's also mentioned in the FSF Free Software Directory and in Wikipedia.
Other interesting effects are HQ2x/3x/4x. These effects interpolate pixels and partially blur the images. They require more computation power than Scale2x/3x/4x but they are very precise and surely worth of checking.
Check also this very interesting paper Depixelizing Pixel Art. With modern processors you can do a lot better than Scale2x.
 scale2x |
 original |