Abstract:
Aiming at the characteristics of hyper-spectral imaging, a scheme for detecting tiny cameras based on three-dimensional features was proposed. The results were accurately determined in the spectral dimension after the suspected target was screened out by the cat's eye effect in the space dimension. According to the camera structure, the reflection spectral characteristics of the visible light camera were analyzed. Based on the geometric optics and radiometry, the detection distance of the system was calculated and simulated. The results show that if the equipment is working properly, the optical power affects the minimum detection distance, while the target size affects the maximum detection distance. A tiny-camera spectral feature verification system was built. The results show that the non-reflective light ratio curve of the target using the absorptive infrared cut-off filter changes smoothly and the value is high. As for the curve of the target using the reflective infrared cut-off filter, the value is high in visible light part while it is low in infrared part, and the curve begins to drop near 700 nm and even mutates where the absolute slope value is more than 10 times as it in the infrared band according to the experimental data. The experimental results are consistent with the expected results of the analysis, which proves the feasibility of hyper-spectral imaging technology to detect tiny cameras.