1. A method for recognizing a face within an image, comprising: performing facial recognition of an input image using a person recognition device, with operations including: classifying a plurality of sample images into classes, images of the plurality of sample images respectively having information on a face of a target to be recognized according to classifications; recording classifications of the plurality of sample images in a database; estimating similarity between the input image and the sample images in the database based on an image classification algorithm for measuring similarity of two images and determining identification thereof; determining a first class of the input image based on a result of the estimated similarity between the input image and the sample image; performing verification for the facial recognition of the input image using a recognition result checking device, with operations including: generating, for each particular class of the database, a binary classifier for identifying a face of a target of the particular class of the database, wherein the binary classifier includes a multiple vector having a similarity measurement value between the input image and a corresponding sample image in the particular class of the database, and wherein the binary classifier is used to identify classes of sample images in the database that are incorrectly identified by the person recognition device; attempting to apply the binary classifier generated for each particular class of the database to the input image; determining a second class of the input image based on a result of successfully applying a particular binary classifier; and combining the first and the second classes determined for the input image; and confirming the facial recognition of the input image based on a result of the combining the first and the second classes.