1. A three-dimensional image system for multiple 3D display, the three-dimensional image system comprising: a monitor displaying an image signal as an image for three-dimensional observation; glasses for three-dimensional observation, the glasses being configured to observe, as a three-dimensional image, the image for three-dimensional observation displayed on a display section of the monitor; a memory provided in the glasses, the memory storing an image parameter correction value correcting image parameters that cause a cubic effect of the image for three-dimensional observation displayed on the display section; a transmitter/receiver that scans the glasses including the memory in order to read the image parameter correction value for three-dimensional observation stored in the memory; and a processor programmed to: set in the monitor, according to a scanning result of the transmitter/receiver, the image parameter correction value for three-dimensional observation stored in the memory, 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 processors configuring the processor, the glasses for three-dimensional observation include first glasses for three-dimensional observation and second glasses for three-dimensional observation, the first glasses for three-dimensional observation include a first memory configuring the memory that stores a first parameter correction value for three-dimensional observation and a second image parameter correction value for three-dimensional observation as the image parameter correction value for three-dimensional observation used when the first observer wears the first glasses for three-dimensional observation and respectively observes the first display section and the second display section, the second glasses for three-dimensional observation include a second memory configuring the memory that stores a third image parameter correction value for three-dimensional observation and a fourth image parameter correction value for three-dimensional observation serving as the image parameter correction value for three-dimensional observation used when a second observer wears the second glasses for three-dimensional observation and respectively observes the first display section and the second display section, the first processor corrects, with the first image parameter correction value for three-dimensional observation or the third image parameter correction value for three-dimensional observation for which priority order is set higher, the first image parameters for three-dimensional observation in a first image for three-dimensional observation serving as the image for three-dimensional observation displayed on the first display section, to correct a cubic effect of the image for three-dimensional observation displayed on the first display section, and the second processor performs control to correct, with the second image parameter correction value for three-dimensional observation or the fourth image parameter correction value for three-dimensional observation for which priority order is set higher, the second image parameters for three-dimensional observation in a second image for three-dimensional observation serving as the image for three-dimensional observation displayed on the second display section, to correct the cubic effect of the image for three-dimensional observation displayed on the second display section.