1. An image monitoring system comprising: an image data acquisition unit for taking in video signals from a camera to acquire image data; and an image recognition unit for carrying out image recognition processing using an inputted image obtained from the image data acquisition unit, wherein the image recognition unit includes: a reference image registration means for registering a reference image selected from among the inputted images; a motion detection means for acquiring motion detection information from the inputted image; an image blur detection means for detecting image blur by comparison of the reference image with the inputted image for edge strength; a similarity computation means for computing a similarity between the reference image and the inputted image; and a camera anomaly detection unit for determining any anomaly in the camera from the motion detection information, the image blur and the similarity, wherein the comparison for edge strength and the computation for the similarity are carried out respectively for an image region excluding a region of a moving object extracted by the motion detection means.