Field of the Invention
The present invention relates to an image generation apparatus, a control method therefor, and a computer-readable storage medium, and especially relates to a technique to generate a privacy protection image.
Description of the Related Art
Along with the widespread installation of surveillance cameras, protection of privacy of individuals shown on the video of the surveillance cameras is becoming increasingly important Japanese Patent Laid-Open No. 2009-225398 describes a technique to protect privacy by generating a foreground image and a background image, which respectively represent an image of people and show no people, from an input image, and making an image, resulting from applying mask processing and filter processing to the foreground image, overlap the background image.
Japanese Patent Laid-Open No. 2009-225398 is based on the premise that a background image is generated in a state where there is no person targeted for protection. If a background image is generated from the video of a surveillance camera in a state where a person exists, the background image will include an image of that person. That is to say, the image of that person is distinguished as a background, and is not generated as a foreground image. As a result, the privacy of that person may not be protected. Furthermore, if a person stays motionless for a long time from, for example, sitting on a chair, a person area may be reflected in a background image as time passes. In this case also, that person area is not treated as an area targeted for protection, and the privacy of that person cannot be protected.