Multi-level printing process reducing aliasing in graphics

摘要

A multi-level printing process using a printer includes the following four steps. 1. A raster image processor (RIP) converts electronic page data to multi-level bitmap data with a specific number of gradation levels Nlev and at a specified spatial resolution. This specified resolution is higher than that of the printer. 2. The multi-level bitmap data is converted to a lower spatial resolution. 3. An image processing technique is used to reduce the number of gradation levels to some lower number Nlevp giving a second multi-level bitmap. 4. The printer, capable to record at least Nlevp different gradation levels at a single pixel, prints out the multi-level bitmap.