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5.1.5.2 Dither Algorithm

Adaptive Hybrid

Adaptive Hybrid usually yields the best output quality; it chooses a modified Floyd-Steinberg error diffusion algorithm or ordered dithering depending upon the image characteristics.

Ordered

Ordered uses a pure ordered dither. It generally yields excellent quality for simple black and white or four color printers without variable drop size or drop modulation; it is not recommended if high quality is desired on six color printers. It is considerably faster than Adaptive Hybrid.

Fast

Fast also uses a pure ordered dither, but uses a very simple black model and makes no attempt to handle multi-level (6-color, variable drop size, or drop modulation) at all cleanly. It is substantially faster than Ordered dither. The quality tends to be quite poor except on simple four color printers. On three color printers, quality is probably competitive with anything else.

Very Fast

Very Fast is similar to Fast, except that it uses a very simple dither matrix that can be looked up much more quickly than the matrix used in the Fast dither. For simple pure black and white images dominated by horizontal and vertical lines, this may actually yield the best results; for other types of image, the quality will be poor.

Adaptive Random

Adaptive Random is similar to Adaptive Hybrid, except that the modifications to the Floyd-Steinberg algorithm are slightly different. This is slower than Adaptive Hybrid on most systems. For some images the quality may be better than Adaptive Hybrid, but generally Adaptive Hybrid should yield slightly superior images.

Hybrid Floyd-Steinberg

Hybrid Floyd-Steinberg uses the modified Floyd-Steinberg algorithm of Adaptive Hybrid on the entire image. Generally, the results are poor in pale regions.

Random Floyd-Steinberg

Random Floyd-Steinberg uses the modified Floyd-Steinberg algorithm of Adaptive Random on the entire image. Generally, the results are poor in pale regions.