Abstract
In accordance with the widespread use of digital cameras, digital displays and color printers, color images have become common in our daily lives. Colors are used frequently to express information even on television and the Internet. Thus, it can be said that colors play a fundamental part in conveying information. In general, the color gamut spreads to the three-dimensional color space. However, in certain circumstances, it becomes necessary to express colors in the gamut represented in a low-dimensional space. For example, colors should be expressed in a one-dimensional gamut when a color image is printed as a grayscale image. Furthermore, the number of dimensions of a valid color gamut for people with color vision impairment such as dichromats is decreased. In this paper, color transformation techniques that improve the visibility of an image in a low-dimensional color gamut are explained. In particular, a detailed description of such transformation techniques for obtaining a monochrome image from a color image is given. Moreover, color transformation techniques for dichromacy are described.
