Fig. 1. Pseudo-thermal optical ghost imaging system. (a) System diagram; (b) GUI panel

Fig. 2. Results of pseudothermal ghost imaging for different size of speckle. (a) English letters "GI"; (b) Chinese character "jiao"

Fig. 3. Comparison of ghost imaging quality for different size of speckle. (a) PSNR; (b) CNR; (c) visibility; (d) SSIM

Fig. 4. Results of pseudo-thermal ghost imaging for different sampling times. (a) Images of "GI" for different sampling times; (b) images of "jiao" for different sampling times

Fig. 5. Comparison of ghost imaging quality for different sampling times. (a) PSNR; (b) SSIM; (c) visibility; (d) CNR

Fig. 6. Comparison of TGI, DGI, and NGI for two objects with different sampling times. (a) English letters "GI"; (b) Chinese character "jiao"

Fig. 7. Imaging quality comparison of TGI, DGI, and NGI for two objects with different sampling times. (a)(b) Comparison of PSNR and SSIM for "GI"; (c)(d) comparison of PSNR and SSIM for "jiao"

Fig. 8. Comparison of TGI and positive-negative correlation imaging results. (a) Comparison of imaging results of "GI"; (b) comparison of imaging results of "jiao"

Fig. 9. Optimization of positive and negative correlation imaging. (a) English letters "GI"; (b) Chinese character "jiao"

Fig. 10. Comparison of optimized histograms of positive and negative correlation algorithm. (a) Comparison of histograms for "GI"; (b) comparison of histograms for "jiao"