Abstract: This study proposed a method for early fire detection in video based on flame contours. The whole fire detection process includes three parts, i.e., candidate fire frame selection, flame region selection and flame contour-based fire decision. In the first step, the suspicious frames are detected and the unlikely frames are removed based on frame selection rules. The second step detects the flame pixels in the candidate fire frames by flame region selection rules. In the last step, four operations (i.e., dilation, erosion, mini region erasing and Canny edge detection) are performed on all flame regions to obtain the exact flame contours and then fire decision rules based on three characteristics (i.e., area, perimeter and roundness of flame contours) are employed to determine whether a fire occurs in the video or not. The proposed approach was tested with several video clips in different environments and the experimental results demonstrated its effectiveness.