In the designing of a screen, making the design so that information important to the user stands out on the screen is a basic technique for creating an easy-to-use screen. As an element influencing the stand-out degree (degree of standing out) of the information, the color can be taken as an example as well as the size and the layout. Successively assigning loud colors (from the loudest one) to the information in descending order of the importance of the information is a commonly-used method. However, as the amount or the number of types/pieces of information to be displayed at the same time increases substantially and the number of colors necessary for expressing the information increases accordingly, just employing the above method (successively assigning loud colors to the information in descending order of the importance of the information) sometimes fails to let each type/piece (hereinafter referred to simply as “type”) of stand out exactly according to the intention of the designer.
For example, although red is a color that easily stands out as a single color, the stand-out degree of the red color on the whole screen (when the whole screen is viewed) drops when the red color is used for a lot of elements on the screen and when similar colors (magenta, orange, etc.) are also used for other types of information. As above, determining the color-scheme in consideration of the color balance on the whole screen is essential for letting each type of information stand out exactly according to the intention of the designer.
However, determining the color-scheme in consideration of the color balance on the whole screen or making an evaluation on whether the color-scheme has been made in consideration of the balance on the whole screen or not is difficult for designers not having sufficient knowledge of colors and design (difficult unless the designer has expert knowledge).
Non-patent Literature 1 describes a technology for evaluating the method for setting the color, the area, etc. of each type of information when multiple types of information differing in the priority are displayed on the screen. With this technology, the appropriateness of the display (visualization) on the screen as a whole can be evaluated in terms of a value called “visualization achievement value (display achievement level)” in consideration of the degree of attracting visual attention and the priority of each type of information on the screen.
A technology described in Non-patent Literature 2 considers that the stand-out degree (degree of standing out) of each color used on the screen can be calculated based on an attractiveness evaluation model (attractiveness evaluation model) that takes into account a characteristic attractiveness (as the degree of attracting visual attention as a single color) and a heterogeneous attractiveness (as the degree of attracting visual attention as compared with other colors). By using this technology, the stand-out degree of each color in consideration of the balance on the whole screen can be calculated.
Patent Literature 1 describes a technology for controlling the way of letting each region in a document stand out by varying the color and the hatching density of each region depending on the area and the degree of importance of the region. With this technology, the coloration can be performed in a simple and easy manner, by changing the saturation and the shade (elements determining the degree of standing out as a single color) depending on the area and the degree of importance of each region.