Spectral Analysis and Modeling of Dot Gain in Ink-jet Printing

Jun Yamashita, Hisato Sekine, Toshiya Nakaguchi, Norimichi Tsumura, Yoichi Miyake

*Department of Information-Science, Graduate School of Science and Technology, Chiba University
1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
 

Journal of The Society of Photographic Science and Technology of Japan, Vol. 66 No. 5, 458-463(2003).

Abstract
We propose a new model to predict the color reproduction of digital halftone image based on the physical model of dot gain. In the previous papers, we reported that the transparency image of halftone is not influenced by optical dot gain. On the basis of this experimental result, in this paper we analyze the optical and mechanical dot gain separately by using the optical microscopes which can take the transparency and reflectance images of the same area. Transparency images of an ink dot are taken with an optical microscope with a six-band camera and the spectral transmittance of each pixel in an ink dot is estimated by the multiple regression estimation method. This obtained spectral transmittance is converted into the amount of cyan, magenta, and yellow (c,m,y) inks in each pixel. Then we can estimate the shape of ink dot by polynomial fitting of ink amount. The transmittance of c,m,y inks of printed images is estimated by using the proposed method and compared with that of practical printed images. This results show that the proposed method is significant to predict the density of ink-jet images.

Full paper ( to appeare )
[PDF](in Japanese)

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