1. An image reading apparatus comprising: a second image detecting section which has relatively higher color measurement accuracy than that of a first image detecting section and detects an image on a transfer medium; and a reading control section which controls the second image detecting section, and also acquires first image detection information based on a result that the first image detecting section has detected the image, the first image detecting section having relatively higher failure detection accuracy than that of the second image detecting section, wherein the reading control section acquires second image detection information in a region of an image that has been detected by the second image detecting section and in which an exclusion detection region has been removed, based on the exclusion detection region that has been determined to contain a failure in the image based on the first image detection information.