The present invention is to protect the right of portrait or privacy of people other than a specific person, and to enable easy recognition of information other than the face of the specific person and the situation around the specific person. Images videotaped by the surveillance cameras are captured in the computer, face images are detected therefrom, and the detected face images are compared with the face image of a specific person registered in the storage device. As the results of the comparison, when these face images do not match with each other, a mosaic process is applied exclusively to the detected face images to protect the privacy of the people other than the specific person, whereas the mosaic process is not applied to the parts other than the faces, such as dress and baggage, thereby keeping them as they are. When these face images match with each other, the face image of the specific person is not applied with the mosaic process, thereby keeping his or her face and remaining parts as they are.