Abstract: When relation between a color of a color chip (a patch) in a color chart and a color of a color chip in an image-captured color chart is calculated, the color chip of the image-captured color chart was manually extracted by operating a keyboard or a mouse. Such an operation had a problem that an extraction error may occur, and that it takes time to manually extract all color chips in the color chart. The present invention solved the problem by a color chart in which recognition can be easily and automatically executed. The color chart includes a plurality of patches, and an automatic recognition marker configured to automatically recognize at least one of the plurality of patches.

Abstract: An object of the invention is to provide an image display system and the like useful for a remote diagnosis and treatment using color information such as a skin color and a tongue color of a patient. There is provided an image display system including: a color chart including a plurality of patches that include at least three patches selected from a group consisting of first to seventh patches having specific colors; an imaging device configured to simultaneously image the color chart and a person to be imaged and acquire image data; and a display device configured to receive the image data and display the image data as an image on a display unit.