1. A three-dimensional image system comprising: a monitor that displays an image signal as an image for three-dimensional observation; glasses for three-dimensional observation for observing, as a three-dimensional image, the image for three-dimensional observation displayed on a display section of the monitor; a storing section that is provided in the glasses for three-dimensional observation and stores an image parameter correction value for three-dimensional observation for correcting image parameters for three-dimensional observation for giving a cubic effect of the image for three-dimensional observation displayed on the display section; a scanning section that scans the glasses for three-dimensional observation including the storing section in order to read information stored in the storing section; and a control section that performs control to set, according to a scanning result of the scanning section, in the monitor, the image parameter correction value for three-dimensional observation stored in the storing section, wherein the monitor includes first and second display sections disposed in positions different from each other and configuring the display section and first and second monitors respectively including first and second control sections configuring the control section, the storing section provided in the glasses for three-dimensional observation stores first and second image parameter correction values for three-dimensional observation serving as the image parameter correction value for three-dimensional observation used when a first observer wears the glasses for three-dimensional observation and respectively observes the first and second display sections, and the first and second control sections perform control to correct, respectively according to the first and second image parameter correction values for three-dimensional observation, first and second image parameters for three-dimensional observation serving as the image parameters for three-dimensional observation in first and second images for three-dimensional observation serving as the image for three-dimensional observation respectively displayed on the first and second display sections.