Image fusion of visual and millimeter wave images for concealed object detection

This paper addresses passive millimeter wave imaging (PMMW) and image fusion for concealed object detection. The PMMW imaging system forms images by means of passive detection of millimeter wave radiation. The PMMW imaging has the capability of detecting concealed metal and dielectric objects under clothing. An image fusion method is developed using the discrete wavelet transform (DWT) and a fusion rule. We adopt the symlets (symmetrical wavelets) for the multi-resolution analysis (MRA). The minimum scheme is applied to the approximation and the weighted-average scheme to the detail coefficients. The experimental and simulation results show the presented technique can detect the concealed object and fuse it with a visual image.