FDRP Diffusion (Fixed Dot Random Placement Diffusion)

A type of FM halftone structure which is made of many pixels of the same size that are evenly dispersed, so the frequency of the pattern is a function of the gray level represented. This is a patented error-diffusion process created by ONYX Graphics for use in large-format printing. The Error Diffusion produces very high image quality, due to its noise and inherent edge enhancement.

• Pros
  • Diffusion helps threshold array emulation and placement when a dot may not be placed using  Stochastic because the error means the decision of where the dot placement is carried over.
  • High frequency detail distributes dots more evenly because it converts each pixel in the image to one of two levels, either black or white.
  • Images look sharper than images hafltoned with other techniques, because the edges have been enhanced.
  •  Used for smoother image quality as seen in fine art or photography

• Cons
  • Solid to lighter colors may display a "band" of dots where there is no dots placed. This is known as the "leading edge" effect.
  • Takes longer to process.
  • Artifacts may be present when going from light to dark (or dark to light) areas.

See Dot Patterns.

See FM Screening.