Chawan Koopipat*, Norimichi Tsumura*, Makoto
FujinoE Kimiyoshi Miyata*, and Yoichi Miyake*
*Graduate School of Science and Technology,
Chiba University, Inage-ku, Chiba and ESeiko
Epson Corporation, Shiojiri-shi, Nagano (Japan)
Journal of Imaging Science and Technology,Vol.45,
No. 6, pp.591- 597(2001).
Abstract
In this study, the modulation transfer functions
of prints, which included both mechanical
and optical dot gain effects were measured
from samples printed by an ink jet printer
on glossy-coated, matt-coated and uncoated
papers. The MTF of prints were measured from
sinusoidal patterns and Fourier transforms
of line spread functions from one-pixel line
and step images. The MTF of print from three
measurement methods were analyzed and compared.
The one-pixel line method was chosen to compare
MTF of prints from different type of papers
and printing directions. In addition, MTF
of papers were also measured by contact sinusoidal
pattern on papers. The point spread function
of ink on each paper was estimated by using
the measured point spread function of paper
in the reflection image model. The results
showed that glossy-coated ink jet paper had
low MTF of paper but high MTF of print. Finally,
printed densities of ink jet images were
predicted using the estimated point spread
function of ink and measured point spread
function of paper. Because the spread function
of ink was estimated as having a gaussian
distribution, which does not correctly represented
the real point spread function of ink jet
printing, the predicted density did not fit
well with the measured density.