1. An image processing apparatus for processing an image captured by an imager device to output the processed image, comprising: a first imaging means for capturing a first image; a second imaging means for capturing a second image; a person detecting means for detecting a person within the first image and the second image; a storage means for storing feature information for use as a database; a feature extracting means for extracting a feature from the person detected by the person detecting means, and for extracting stored feature information on the feature from the database; a feature amount processing means for processing the feature, using a feature amount extracted by the extracting means from within the stored feature information on the feature; and an output image generation means for generating an output image based on the processed feature; wherein the processing means for processing the feature, using a feature amount includes processing for replacing the feature amount with a value calculated from the feature amount using a function; and wherein the function of calculating a value to be substituted for the feature amount receives a time or an operating time of the apparatus as an input parameter, and a value calculated with the same feature amount inputted to the processing means varies depending on the time or the operating time of the apparatus.