Noise reduction and object enhancement in passive millimeter wave concealed weapon detection

Passive MM wave offers the advantage of penetration for concealed weapon detection. Its ability to penetrate through fog, smoke, clothing etc. makes it an attractive candidate to look for weapons concealed underneath a person´s clothing. The sensor technology has advanced to a point where it is possible to generate real time video sequences. However, noise and blur are still severe problems. The work reported here investigates the problem of simultaneous noise suppression and object enhancement in passive millimeter wave video sequences. The basis for the approach is provided by undecimated wavelet transforms in the spatial dimension and motion compensated filtering in the temporal dimension. The paper presents the underlying principles of the approach as well as experimental results.