Estimating the amount of cyan, magenta, yellow, and black inks in arbitrary colour pictures

Authors: Verikas, Antanas¹; Bacauskiene, Marija²; Nilsson, Carl-Magnus³

Source: Neural Computing & Applications, Volume 16, Number 2, February 2007 , pp. 187-195(9)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

Abstract:

This paper is concerned with the offset lithographic colour printing. To obtain high quality colour prints, given proportions of cyan (C), magenta (M), yellow (Y), and black (K) inks (four primary inks used in the printing process) should be accurately maintained in any area of the printed picture. To accomplish the task, the press operator needs to measure the printed result for assessing the proportions and use the measurement results to reduce the colour deviations. Specially designed colour bars are usually printed to enable the measurements. This paper presents an approach to estimate the proportions directly in colour pictures without using any dedicated areas. The proportions—the average amount of C, M, Y, and K inks in the area of interest—are estimated from the CCD colour camera RGB (L*a*b*) values recorded from that area. The local kernel ridge regression and the support vector regression are combined for obtaining the desired mapping L*a*b* ⇒ CMYK, which can be multi-valued.

Keywords: Neural networks; Kernel ridge regression; Support vector regression; Offset printing; Colour print quality

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s00521-006-0066-6

Affiliations: 1: Email: antanas.verikas@ide.hh.se 2: Email: marija.bacauskiene@ktu.lt 3: Email: cmn@ide.hh.se

Publication date: 2007-02-01