Fig. 1. Structure diagram of asynchronous sampling terahertz imaging system

Fig. 2. Diagram of high speed scanning terahertz imaging system

Fig. 3. Physical image of enamel sheet

Fig. 4. Three-dimensional side view grayscale image of enamel sheet. (a) Skeletal image; (b) pulmonary image

Fig. 5. Two-dimensional image of enamel sheet. (a) Grayscale image of enamel sheet; (b) false color image of enamel sheet