Fig. 1. Simulation of reconstruction of compressive sensing images. (a) Original image of phantom; (b) reconstruction time of phantom based on TVAL3 algorithm at different resolutions

Fig. 2. Comparison of imaging results. (a) Wide-beam matrix modulation sampling (PSNR is 44.83); (b) single-pixel random sampling at ideal sampling position (PSNR is 45.67); (c) single-pixel random sampling at random sampling position (PSNR is 24.55)

Fig. 3. Schematics of imaging system. (a) Terahertz wide-beam imaging system based on block compressive sensing theory; (b) partial signal light paths in block compressive sensing imaging system based on single-pixel random sampling

Fig. 4. Imaging results of wide-beam matrix modulation sampling system under different conditions. (a)(d) Physical maps of imaging letters; (b)(e) imaging results without reference light path; (c)(f) imaging results with reference light path

Fig. 5. Two imaging results of letter “H” in block compressive sensing system based on single-pixel random sampling. (a) Imaging result at first set of sampling positions; (b) imaging result at second set of sampling positions

Fig. 6. Two imaging results of letter “T” in block compressive sensing system based on single-pixel random sampling. (a) Imaging result at first set of sampling positions; (b) imaging result at second set of sampling positions