UPSCALE FILTERS

G’MIC provides a whole range of upscaling filters. They were developed for different image types and produce – sometimes significantly – different outputs.

Upscale [DCCI2x]

Scales by a factor of 2, fast, easy to use, few parameters, quite good preview.

Upscale [Diffusion] Depending on parameters, this much used filter can be very slow and produces relatively soft outputs.

Upscale [Edge]

Edge sharpening upscale tries to keep edges as good as possible. Few parameters control the universal filter, which supports scaling with integer factors between 2 and 8. Bicubic usually produces the better results.

Upscale [Noise]:

Simple factor 2 scaler, with random (noise) pixels.

Upscale [Scale2x]

Filter for indexed images with few colours, scales by integer factors between 2 and 27.

Upscale [Recursive2x] This is one of the most modern upscale filters. It requires a relatively large amount of computing time. The results are good, but not necessarily outstanding. The preview is limited, so it often takes several experiments to get the best results.

Upscale [Solver2x]

Modern and widely configurable. The preview is limited and remarkably slow, but the results are still interesting. It will probably be replaced today by Upscale [Recursive2x].

Upscale [Xbr2x]

The simplest upscale filter with a fixed factor of 2 and no parameters. The results are surprisingly good, but often quite hard and come from a program called ImageResizer.

Upscale [Iain 2x]

Another parameterless upscale filter with a fixed factor of 2. The results are clearly softer and thus often better suited for photos.

In a superficial comparison of all these methods with a photo, the results are relatively similar – only the Upscale [Solver2x] produces a strikingly hard result, provided the Unsharp option is not active.