Feasibility study on low-resolution uncooled thermal imagers for home-security applications

The feasibility of using low-resolution thermal imagers for home security a pplications is analyzed, taking low cost as the primary consideration. The smallest possible sensor size and resolution are chosen as the operative cr iteria and derived by simulation, in accordance with the optical constraint s of a general home security system and the minimum target feature recogniz able using image processing. Low-resolution simulated thermal images were g enerated by downgrading the high-resolution images captured by an uncooled IR camera, through sampling and modification. Caricatures of human beings a nd family pets are extracted for recognition using aspect-ratio and neural network methods, which are compared with one another for detection probabil ity. It is demonstrated that highly reliable detection of human beings or p ets with a minimal target feature of 8x8 pixels can be obtained using the n eural network method. Also, a fire can be detected early using its temporal size variation and higher temperature. Finally, low-cost fabrication of th e proposed low-resolution passive infrared imaging system with an uncooled FPA sensor utilizing a fully standard application-specific IC CMOS process is also discussed in detail, (C) 2000 Society of Photo-Optical Instrumentat ion Engineers.