Imaging principles of a camera and a grand based millimeter wave radiometer were analyzed. Segmentation and recognition methods of optical images were discussed. The temperature and brightness relations between the terrain surface and sky were discussed .The method of computing the antenna temperature of the terrain was given. Therefore a new technique to generate the grand based millmeter wave radiometric images from visual optic images was presented. The technique was expected to be a useful tool to generate reference images of the matching navigation. Experimental results show that the technique is completely practicable.