Riso Kagaku Corporation

Michael Mehigan

Mitsuaki Ishitoya

Noriaki Nagao

Musashi Hirata

Jianmin Xiong

Nobuko Kubota

Nami Higashio

An original color image data is converted to halftone image data having information on density of pixels by a predetermined gray conversion. The predetermined gray conversion includes an RGB ratio adjustment, an RGB ratio adjustment is carried out on reference image data employing different ratios of R, G and B, the results of the predetermined gray conversions including the RGB ratio adjustments employing the different ratios of R, G and B carried out on the reference image data are graphically shown on a screen, an optimal value of the ratio of R, G and B is determined on the basis of comparison of the results of the predetermined gray conversions graphically shown on the screen, and the predetermined gray conversion including an RGB ratio adjustment employing the optimal value of the ratio of R, G and B is carried out on the original color image data.

Method of and apparatus for carrying out gray conversion on color image

A printing control apparatus for controlling a stencil printing machine ( ), wherein a stencil sheet, which is made on the basis of image data, is wound around a printing drum ( ) with which a print sheet ( ) is held in pressured contact to perform a stencil printing operation, provides the stencil printing machine with image data representative of an image to be reproduced as an object, and printing order information representative of a page order in which the printing operation is performed using image data, an ink color for the printing drum to be used, and a timing in which one printing drum is replaced with another one. In accordance with the printing order information, the ink color contained in image data is detected and an order for each page to be printed is determined on the basis of a user's print request to execute the printing operation according to the page order and to reduce the number of times the printing drum is replaced with.

Printing control apparatus having printing order information producing function

A user PC for controlling a stencil printing machine having a plurality of exchangeable printing drums, wherein respective printing drums are mounted with respective perforated stencil sheets which are formed by a stencil-making processing section on the basis of image data, and a print sheet is held in press contact with the plural printing drums to perform a stencil printing process with first and second stencil-printing processing sections is disclosed as having a registering function to register printing ink colors to be used for printing with the respective printing drums by enabling reading-in of a printer driver and to store useable ink color information, a function to produce display data to display contents of the ink-color designating information produced by the designating section for the respective printing drums.

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Amimachi, Japan

Michael Mehigan