1. An image display system comprising: an image display apparatus; and an image providing apparatus that provides the image display apparatus with one or more pieces of image information which may respectively include one or more projections of a person as a detection target, wherein the image providing apparatus includes: a calculating module that calculates a detection precision for detecting the detection target from the image information so as to satisfy a restrictive condition designated for the provision of the one or more pieces of image information based on current processing capacities of the image display apparatus and the image providing apparatus, a current communication processing capacity between the image display apparatus and the image providing apparatus, and an amount of information corresponding to the number of the one or more pieces of image information; a detecting module that receives a designation of the kind of a detection target and detects the detection target from each of the one or more pieces of image information at the calculated detection precision, the detecting module detecting, when a projection of a person is designated as the detection target, the projection of the person from an image related to each of the one or more pieces of image information and calculating the number of designated detection targets included in the image information; and a providing module that arranges the one or more pieces of image information in descending order of the calculated number to create provision information, the image display apparatus displays the provision information and image information included in the provision information, the restrictive condition is designated from any of time, power consumption, and display screen size, and when time is designated as the restrictive condition, the calculating module calculates the detection precision such that the period of time from the moment the detecting module receives a designation of a detection target to the moment the image display apparatus displays the provision information is equal to or within the designated time.