In recent times, research on the detection of fire flames using surveillance cameras with machine vision has gained momentum. The image processing approach involves the extraction of the fire flame pixels from a background by using frame difference technologies. Healey et al. (1993) presented a fire detection algorithm using a color video input with a pre-partitioning scheme under some restricted conditions, without rejecting the similar fire-like alias. Phillips et al. (2002) and Celik et al. (2007) conducted studies on computer vision by using spectral analysis and the flickering property of fire flame pixels to recognize the existence of fires at a scene. Hue and saturation are adopted as feature vectors to extract the fire pixels from the visual images (Chen, 2003). Fire flame features based on the HSI(hue, saturation, intensity) color model are extracted, and regions with fire-like colors are roughly separated from the image by the color separation method (Horng, 2005). Then, the image difference method based on chromatics is used to remove spurious fire-like regions such as objects with similar fire colors or areas reflected from fire flames. A fuzzy-based dominant flame color lookup table is created, and fire regions are automatically selected (Wang, 2006). However, either the solution does not consider the temporal variation of flames or the approach is too complicated to process in real time.
Fire suppression systems usually use water to extinguish fires due to its good ability to suppress fire. Chen et al. (2004) developed a water-spraying-based fire suppression system. The fire searching method is realized based on computer vision theory using one CCD camera that is installed at the end of a fire monitor chamber. However, it is necessary to calculate the changes in the space coordinates of the fire with displacement and the pivot angle of the CCD camera in the fire searching process. Ho (2009) proposes a fire-tracking scheme based on CAMSHIFT. The CAMSHIFT algorithm is applied to track the trajectory and compute the 2D positions of the specified moving fire-fighting robot in real time with the aid of a vision system. Yuan (2010) adopted the computer vision techniques to extract color and motion characteristics for real-time fire detection. However, the system was designed to move a water gun along a fixed path using computer-based control. Hence, the monitor ranges of the scene are limited and not sufficiently flexible.