초록 ▼

A high addressable multibit screening device and method for use in a PDL interpreter environment achieve improved printing resolution and quality. A PDL interpreter receives a PDL document from a host source, which identifies one or more objects that can be fully toned (black) or partially toned (li

A high addressable multibit screening device and method for use in a PDL interpreter environment achieve improved printing resolution and quality. A PDL interpreter receives a PDL document from a host source, which identifies one or more objects that can be fully toned (black) or partially toned (line art or images). Each of these objects can be processed differently. Fully toned objects are processed within the interpreter and directly output in a predetermined output. Partially toned objects are sent to a high addressable screening module within the interpreter for processing prior to outputting in a desired output format. The high addressable screening module screens the partially toned objects to obtain multibit screened data for output. This can be achieved by converting an array of single threshold values to an array of three or more sub-threshold values in a way that preserves the pattern specified by the original threshold array (one bit per pixel image), but improves the quality of the rendered image relative to the quality of a one bit per pixel (per colorant) image. The partially toned data is then output with the fully toned objects for subsequent printing. This achieves an increase in available tints and spatial frequency for a given halftone pattern while reducing memory requirements.

대표청구항 ▼

1. A rendering apparatus that renders page description language documents for printing by a high addressable printer, the documents having at least one of a fully toned object and a partially toned object, the apparatus comprising:a page description language interpreter having an input section and a

1. A rendering apparatus that renders page description language documents for printing by a high addressable printer, the documents having at least one of a fully toned object and a partially toned object, the apparatus comprising:a page description language interpreter having an input section and an output section, the input section receiving a document representing a page to be printed, the document being formatted in a page description language; means within the interpreter for distinguishing a partially toned object and a fully toned object; means for processing a fully toned object and outputting the fully toned object as fully toned object data in a predetermined output format; means for screening the partially toned objects to obtain multibit deep partially toned data in a predetermined format, which includes means for determining a threshold pattern array at a given addressability; means for calculating sub-pixel thresholds from the threshold pattern array; means for screening by comparing an input signal against the sub-pixels to achieve multibit deep screening; and means for sending the fully toned object data and the halftone data to a printer for subsequent printing by a high addressable printer.