Image processing apparatus, image forming apparatus, and image processing method

An anomaly detecting unit detects an anomaly object in a target image. A characteristic amount watching unit watches at least two basic characteristic amounts of the anomaly object, determines whether values of the basic characteristic amounts satisfy a predetermined watching determination condition of any one of predetermined plural anomaly types or not, if it is determined that the values of the basic characteristic amounts satisfy the watching determination condition, determines as an auxiliary characteristic amount for the anomaly object a characteristic amount corresponding to the anomaly type of which the values of the basic characteristic amounts satisfy the watching determination condition, and starts watching a value of the auxiliary characteristic amount. An anomaly type determining unit determines an anomaly type of the anomaly object on the basis of the basic characteristic amounts and the auxiliary characteristic amount currently watched by the characteristic amount watching unit.