Fig. 1. Schematics of computational ghost imaging setup with the OPBR speckle patterns. A laser beam incidents on a DMD modulated by a sequence of RB speckle patterns. The modulated light propagates through turbid water and then falls on the object. The collected intensity fluctuation from the bucket detector can be used to retrieve the image by a second-order correlation algorithm. The volume of the water in the tank is 2 m × 0.76 m × 1 m.

Fig. 2. The generation of the OPBR speckle patterns with different modulation speckles. The projection speckle size on DMD equals 10.6 µm × speckle size.

Fig. 3. Results for the retrieved image of the object of digit 3. Retrieved images and corresponding CNRs by the RB speckle patterns and the OPBR speckle patterns with different speckle sizes in the clear water (0.517 NTU). The upper part of the image shows the numerical comparison of CNR values, while the lower part shows the corresponding ghost-imaging results obtained. Each row represents the speckle imaging results obtained using the same type of speckle patterns but with different sizes, while each column represents the results obtained using the same size but with different types of speckle patterns. The projection speckle size on DMD equals 10.6 µm × speckle size.

Fig. 4. The CNR by different OPBR speckle patterns with different sizes of speckles in turbid and turbulent water. The projection speckle size on DMD equals 10.6 µm × speckle size.

Fig. 5. The CNR by different OPBR speckle patterns for the object 1 and object 2 with different random sequences in the turbulent water. The projection speckle size on DMD equals 10.6 µm × speckle size.

Fig. 6. Simulation results using the proposed OPBR speckle patterns and RB speckle patterns with a digit 3 object. The retrieved images by OPBR speckle patterns are presented at the top and the retrieved images by RB speckle patterns are presented at the bottom. The ghost images by RB speckle patterns of the digit 3 retrieve with the projection speckle size from 10.6 µm × 10 to 10.6 µm × 100. The proposed OPBR speckle patterns are modulated by the speckles with the speckle size from 10.6 µm × 10 to 10.6 µm × 100.