A method for detecting flame and smoke using spatial analysis of video input (40) provided by a video detector. The video input (40) consists of a number of individual frames, wherein analysis is performed on each individual frame to detect and outline regions that may contain smoke or flame (42). Based on the defined outline or boundary of each detected region, spatial features associated with the region are extracted (52), such as perimeter/area and surface area/volume. The extracted spatial features are related to one another (54) to determine the likelihood that the region contains smoke or flame. Extracted spatial features may be related to one another using a power law relationship that provides an indication of the turbulence associated with a bounded region, wherein turbulence is a characteristic of both flame and smoke.