| Extracted from Pike v7.8 release 866 at 2018-02-09.

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Image
Image.Colortable

# Method Image.Colortable()->floyd_steinberg()

Method floyd_steinberg

  `object floyd_steinberg()`
  `object floyd_steinberg(int bidir, int|float forward, int|float downforward, int|float down, int|float downback, int|float factor)`

Description

  Set dithering method to floyd_steinberg.

  The arguments to this method is for fine-tuning of the algorithm (for computer graphics wizards).

  original | floyd_steinberg to a 4×4×4 colorcube | floyd_steinberg to 16 chosen colors

Parameter `bidir`

  Set algorithm direction of forward. -1 is backward, 1 is forward, 0 for toggle of direction each line (default).

Parameter `forward`
Parameter `downforward`
Parameter `down`
Parameter `downback`

  Set error correction directions. Default is forward=7, downforward=1, down=5, downback=3.

Parameter `factor`

  Error keeping factor. Error will increase if more than 1.0 and decrease if less than 1.0. A value of 0.0 will cancel any dither effects. Default is 0.95.

Returns

  the object being called