Screening module examples

Modules
	A simple bilevel screen that cannot be written in PostScript
	The htm4x4 example of the modular screening API implements a primitive bi-level halftone that could not be produced using conventional PostScript/PDF thresholds, because pixels can be extinguished as well as lit when moving from one shade to a darker shade.
	A set of multi-level dispersed screens
	The htm8ml example of the modular screening API implements a multi-level screening technique which produces a configurable number of levels, and where the transition between levels is dispersed using a stochastic screen cell.

Detailed Description

The RIP's modular screening API provides a method to extend the screening options available to jobs running on the RIP. Standard PostScript/PDF screening actions are implemented as static data, but the core screening API provides the ability to implement dynamically changing actions on the page buffer - for example, true error diffusion screening.

The modular screening API is implemented as a module that can be linked directly into an HHR RIP.

The SDK includes two examples of the modular screening API: a simple bilevel halftone screen that includes the ability to extinguish as well as light pixels (non-monotonic screening), and an 8-bit multiple bits per sample screen.