Toshiba Tec Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Toshiba Corporation

Ronald Pellar

William C Kress

Hiroki Umezawa

A multi-bit halftone generating system provides for halftone intergeneration in printers which can print dots of plural gray scale levels. Input image data includes information for more gray scale levels than can be handled by those associated with a printing device. Higher order bits of the pixels of the electronic document are used to select a gray scale level from those available from the printer. Remaining bits are used to generate a halftone pattern which is superimposed upon this selected gray scale. Thus, improved dither rendering is quickly and efficiently accomplished and improved image generation results from using the gray scales available from the printing device.

Generating multi-bit halftone dither patterns with distinct foreground and background gray scale levels

In accordance with the present invention, a system and method are described for producing pure gray tones on a multi-color document output device that includes a system for operating on device independent color data having multiple color components, which color data corresponds to one or more associated electronic documents. The system and method function to extract gray data by the use of tristimulus values in a range specified by a functional relationship of a selected tristimulus value.

System and method for extracting grayscale data in accordance with a prescribed tolerance function

In accordance with the present invention, a system and method are described for producing pure gray tones on a multi-color document output device that includes a system for operating on device independent color data having at least three color components, which color data corresponds to one or more associated electronic documents. The system and method function to extract grayscale data from such a device independent color data description, which grayscale corresponds to a rendering and a single color space. Such resultant data, inclusive of a color data portion and a grayscale portion, is thus completed in device independent form.

System and method for extracting grayscale data within a prescribed tolerance

In accordance with the present invention, a system and method are described for producing pure gray tones on a multi-color document output device that includes a system for operating on device independent color data having multiple color components, which color data corresponds to one or more associated electronic documents. The system and method function to extract grayscale data by the use of chromaticity properties of an input image.

System and method for determination of gray for CIE color conversion using chromaticity

This invention is directed to a system and method for performing color corrections on color image data. More particularly, this invention is directed to a system and method for performing color corrections on color image data in a primary color system. This invention is particularly useful in performing color corrections on color image data that is to be output on a image processing apparatus.

System and method for color correction

This invention is directed to a system and method for setting output characteristics of an image rendering device. Image data encoded relative to a red-green-blue color space is received in a vector format D, such that each value of D corresponds to a red component value, a blue component value and a green component value. Data representing a contrast adjustment matrix C is then received, such that the values of the matrix C are constant values associated with a selected contrast adjustment for the image data. Data representing a saturation adjustment matrix S is then received, such that the values of the matrix S are constant values associated with a selected saturation adjustment for the image data. The values of the matrix S also correspond to values of a selected m by n masking matrix A. A brightness adjustment matrix B is then received. The values of the brightness adjustment matrix B are associated with brightness adjustment of the red component, with brightness adjustment of the green component, and with brightness adjustment of the blue component. An output image data D' is then calculated, encoded in a vector format, such that D&#x2032;=S&#xd7;C&#xd7;D+B.

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Orange, CA, United States of America

Ronald Pellar