The invention provides an image storage and display system including: an image storage server that includes an image file storing unit for storing image data; and image display terminals that are connected to the image storage server via a network and display an image sent from the image storage server. In the image storage and display system, the image storage server includes: an information managing unit that acquires and manages information on a system including at least one of environmental information and operation information of the system; and an image file compressing unit that sets an optimum compression ratio on the basis of the information to compress the image and stores the image in the image file storing unit. According to the constitution, it is possible to reduce time for, for example, adjustment of a compression ratio of an image by a user or a service person by automatically optimizing the compression ratio.