HYBRID VECTOR HALFTONE SCREENING AND ERROR DIFFUSION

摘要

Vector halftoning and error diffusion are combined to provide a quantization method that yields high quality rendered images while demanding fewer system resources. For instance, the method is tolerant of resolution reductions in secondary or auxiliary channels to the vector halftoning process. Accordingly, these secondary pixel data channels can be sub-sampled and/or bit-depth reduced for transmission bandwidth conservation and/or reduction in data storage requirements. Restoring the resolution of the low resolution channels provides estimated image data to arrange or align with high resolution target channel data for the vector halftoning process. Error from marking decisions generated by the vector halftoning process is diffused to neighboring unprocessed pixels. The method also allows for the use of a small vector halftone threshold array while providing quantized images with fine texture and wide color gamuts. In some embodiments error diffusion is distributed according to vector error diffusion.