According to one embodiment, an image detection system includes an imaging apparatus, an edge extraction unit, a specific-edge extraction unit, a candidate area extraction unit, and a to-be-detected area determination unit. The edge extraction unit extracts edges each representing a boundary line between areas with different features. The specific-edge extraction unit extracts specific edges including at least remaining edges present in background image and input image. The candidate area extraction unit extracts candidate areas for a preset area to be detected. The to-be-detected area determination unit determines the area to be detected from candidate areas extracted.