The needs for color printing is increasing to output color documents used for presentation data and the Internet. To meet these needs, high-speed electrophotographic color printers are becoming popular. Okidata has also commercialized electrophotographic color printers. This paper describes the hardware and software design technology of an electrophotographic color printer controller using a ta...

In printing the final color image reproduction quality depends on the quality of the digital image as well as the properties of the printing system and the paper used. Although it is well known that the paper has a large influence on the print result it is seldom specified according to image quality attributes. Computer screens, digital cameras and printers are all technically specified with re...

Traditionally the choices made by color separation are expressed as amounts of each of the available colorants to use for each of the reproducible colors. Halftoning then deals with the spatial distribution of colorants, which also results in the nature of their overprinting. However, having a colorant space as the way for color separation to communicate with halftoning gives access only to som...

A Perceptual Significance Hierarchy (PSH) for line art images is developed which represents the relative perceptual significance of each image component. This is possible through the use of a set of image-features which are used by the human visual system. The PSH and related rho-space computer vrsion algorithms can be used to automate the fake color separation process used by the printing indu...

Seeing means perceiving light from an external source which was scattered in a material medium and reemitted toward the observer’s eye. Thereby colors are the result of wavelength dependent absorption processes. The physical basis of color as molecular or atomic phenomenon is state-of-the-art in science, both in experimental and in theoretical respect. But to the authors knowledge, the deriving...

Many high end printing systems store and/or transmit compressed images to save bandwidth, memory, and disk space. Prior to printing, the system will decompress and then color correct the image to compensate for the characteristics of a particular printer. In the conventional architecture, the decompression step converts the image from some encoded format (e.g. JPEG with Huffman encoding) into t...

The stochastic screen has traditionally been used to preserve images with fine features as well as to reduce printing Moiré of images that contain input periodic structures. However, the stochastic screen also has experienced more difficulty in maintaining color stability in long press runs. Kodak, using its multilevel printing architecture, has created a new stochastic screening technology, wi...

“Color space” refers to a specific system of coordinates that allows us to describe a particular color of light. In this article we discuss the concept of the color of light and the concept of a “color model”—which if precisely specified is today most often described as a “color space”. We then describe in some detail a number of specific color spaces used in a wide range of fields. TABLE OF CO...

Reproducing Color Images with Custom Inks by Eric J. Stollnitz University of Washington Advisor Associate Professor David H. Salesin Computer Science and Engineering Chairperson of Supervisory Committee Professor Loyce M. Adams Applied Mathematics This dissertation investigates the general problem of reproducing color images on an offset printing press using custom inks in any combination and n...