Cigarette smoking poses dangers to our health, environment and safety. Therefore, when smoking is prohibited in certain areas, the enforcement of this rule is important. Using physical smoke detectors poses constraints. A smoke detector is not suitable for the level of smoke produced by a cigarette, especially in large areas. Letting a human monitor a designated area through a surveillance camera is rather inefficient. If a computer is programmed to recognize this activity, an automatic system can be set up to alert humans when the computer "sees" someone smoking through a video camera.