Аннотация:We demonstrate the improvement of the quality of the image captured by TS4 - the commercially available THz passive camera manufactured by ThruVision Systems Ltd. The measurements range of this device reaches 10 meters. Our approach is based on application of novel spatial filters and algorithms, developed by us for computer processing of passive THz images produced by the various THz cameras. In our opinion, the most important result of this paper consists in a demonstration of the possibility of using a passive THz camera to observe a difference in temperature on the human skin if this difference is caused by different temperatures in the inside of the body. Such possibility was proposed by Vyacheslav Trofimov on the Conference in Baltimore (April 2012) as well as and in [20]. We discuss two physical experiments, in which a person drinks hot and cold water. After computer processing of images captured by passive THz camera TS4 we may see the pronounced temperature trace on the human body. We illustrate this phenomenon by a series of images captured by passive THz camera in real time. As we believe, these experiments allow us wide applications of passive THz cameras for the detection of objects concealed in the inside of the human body because the difference in temperature that will be reflected on the human skin. Modern passive THz cameras have not enough resolution in temperature to see this difference. However, computer processing allows us to enhance it for this application. Using computer processing one may enhance the image quality and delete noise on the images. In some cases, it is possible to achieve full de-noising of the image.