In this paper, we consider a dual-mode halftoning process for the electrophotographic laser printer - a low
frequency halftoning for smooth regions and a high frequency halftoning for detail regions. These regions are
described by an object map that is extracted from the page description language (PDL) version of the document.
This manner of switching screens depending on the local content provides a stable halftone without artifacts
in smooth areas and preserves detail rendering in detail or texture areas. However, when switching between
halftones with two different frequencies, jaggies may occur along the boundaries between areas halftoned with
low and high frequency screens. To reduce the jaggies, our screens obey a harmonic relationship. In addition, we
implement a blending process based on a transition region. We propose a nonlinear blending process in which
at each pixel, we choose the maximum of the two weighted halftones where the weights vary according to the
position in the transition region. Moreover, we describe an on-line tone-mapping for the boundary blending
process, based on an off-line calibration procedure that effectively assures the desired tone values within the
transition region.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.