Towards Recognition of Humans and their Behaviors from Space and Airborne Platforms: Extracting the Information in the Dynamics of Human Shadows

This paper proposes the use of shadows and shadow dynamics for the recognition of humans and human behavior. ldquoShadow biometricsrdquo may be a useful addition to the biometrics arsenal; shadows can be used in isolation, or in addition to the dasiadirectpsila (body) observation. Shadows may offer significantly more information could be obtained (larger image areas and more behavioral dynamics details) than in a direct observation of humans from above. Thus, shadow biometrics enables dasiaabove-the-headpsila remote biometrics, based on which future space/airborne imaging systems may be able to recognize and track suspects (such as wanted terrorists) by analyzing shadow dynamics (e.g. gait). Beyond the recognition of humans, the movement dynamics may offer information on specific types of behavior, such as those of suicide bombers, rioters or other aggressive individuals. The paper describes the image processing and feature analysis steps and illustrates them with examples.