Method and apparatus for color correction of color devices for various operating conditions

Abstract

Methods and apparatuses for color correction of color device for various operating conditions. In at least one embodiment of the present invention, operating under a current condition, a color correction operation that is derived from color correction operations defined for other conditions is performed on the color data. In another embodiment, a device profile for managing colors for a color device operating under one condition is interpolated from the device profiles for the color device operating under other conditions (e.g., based on the input received from a user interface according to the perception of the user or based on the measurement of a sensor). The interpolation can be based on the input received from a user interface according to the perception of the user or it can be based on the measurement of a sensor or a set of sensors. Various operating conditions for a color device (e.g., a scanner, a camera, a video camera, a printer, a display device such as a CRT monitor or an LCD display panel, a television set, or others) include chromaticity and illumination of ambient light, background color for a display device, characteristics of print media for a printer, humidity, temperature, pressure and ink level for an ink jet printer, the age of a light source for a scanner, and others.

Description

[0001]This application is a divisional of U.S. patent application Ser. No. 10 / 419,001 filed on Apr. 18, 2003.FIELD OF THE INVENTION[0002]The invention relates to color devices, and more particularly to color correction for various operating conditions.BACKGROUND OF THE INVENTION[0003]Color devices include input devices (e.g., scanners, still cameras, video cameras), output devices (e.g., printers), and display devices (e.g., Cathode Ray Tube (CRT) monitors, LCD display panels, television (TV) sets, high definition television sets). The operation of a color device is typically influenced by a number of operating conditions. For example, the scanned image of a scanner may be influenced by the age of the light source of the scanner; the appearance of the output of a printer under a standard viewing condition may be influenced by the characteristic of print media (e.g., paper) and ink level, as well as environment conditions such as humidity, temperature and pressure. The appearance of ...

AI Technical Summary

Problems solved by technology

A more complex situation may arise in the presence of mixed illuminants, for example when the fluorescent light in an office is mixed with the daylight coming through the windows.

Thus, user experiences show that color adjusted (corrected) in this way may be perceived as having a hue shift (a color cast); and, such an approach may not be the preferred solution from the point of view of perceived color for an observer.

However, adjusting the white point temperature and the target gamma may not be enough to compensate the influence of the ambient light.

For example, when the screen color appears to have a hue shift of colors other than greenish or pinkish (purplish), the adjustment of the white point temperature may not be able to correct the color and remove the hue shift.

If the display is calibrated for daylight illumination, the display may look greenish under office fluorescent illuminant; and, there is no way to correct such a hue shift based on the white point temperature adjustment; this may cause frustration for the user in not being able to adjust the color of the display to its preferences with the limited resources available for changing only the white point temperature of the display.

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