Dot profile model-based direct binary search

Abstract

A dot profile model to compensate dot shape irregularity errors of inkjet printers is proposed. Previous tabular approaches for parameterizing the printer model rely on the measurements of the gray level of various printed halftone patterns. However, lots of patterns need to be printed and scanned if the printer generates large drops of colorant. To solve this problem, we propose to simulate the appearance of the rendered patterns so that the model parameters can be computed analytically. The simulation uses the mean dot as the printer dot profile and saturated addition to resolve dot overlap. Besides, we incorporate a standard definition (SD) and a high definition (HD) equivalent gray-scale representation of the printed halftone image produced by the dot profile model into the direct binary search (DBS) algorithm. Experimental results show great improvement in the mid-tone and shadow regions over the printed image halftoned by the original DBS. The HD model further enhances details in the shadows.