This paper proposes a modified jointly-blue noise mask (MJBNM) method using an S-CIELAB color measure. For color image halftoning, the jointly-blue noise mask (JBNM) method provides a visually pleasing pattern for single and multiple color planes. However, the halftone outputs of a JBNM mask show a higher chrominance error. The SCIELAB metric, a modified color metric from CIELAB, includes the spatial-color sensitivity of the human eye in the metric to account for how spatial patterns influence color appearance and color discrimination. To reduce the chrominance error, the low-pass filtered error and SCIELAB chrominance error are both considered during the mask generation procedure and calculated for single and combined patterns. Based on the calculated low-pass filtered error, the patterns are then updated by either adding or removing dots from the multiple binary patterns. Finally, the pattern that shows the lower S-CIELAB chrominance error is selected. The proposed algorithm can produce a visually pleasing halftoned image with a lower chrominance error than the JBNM method.
Yong-Sung Kwon, Yun-Tae Kim, Ho-Keun Lee, Yeong-Ho Ha, "Modified Jointly-Blue Noise Mask Approach Using S-CIELAB Color Difference" in Proc. IS&T 9th Color and Imaging Conf., 2001, pp 194 - 198, https://doi.org/10.2352/CIC.2001.9.1.art00036