韩超 Han Chao’s scientific contributions

The total variation image inpainting algorithm needs more iterations to remove the text and scratches. It is not ideal for the preservation of edge details, and has a staircase effect. The peak signal to noise ratio of the restored image is relatively low. Aiming at these defects, an improved algorithm is proposed. The logarithmic operation and additional directional gradient operator are added into the regular term of the original algorithm to avoid the staircase effect, reduce the number of iterations, and reduce the smoothing of image at edge details. Simulation results show that the improved algorithm reduces the number of iterations retains the details of the image, well and the restored image has good visual effect.

An error diffusion algorithm based on the angular-spectral diffraction theory is proposed. The complex amplitude hologram of a three-dimensional object is calculated by the layered angular-spectral algorithm. The error diffusion method is used to obtain the phase-only hologram. The clear reconstructed image is reconstructed and the speckle noise of the phase-only holographic reconstructed image for a three-dimensional object is suppressed. The simulation experimental results verify the feasibility and superiority of this algorithm. This proposed algorithm can significantly improve the quality of reconstructed images.

The classical total variation image inpainting algorithm costs more iterations and time to remove the text and scratches. Aiming at this problem, we propose an improved algorithm. Firstly, the diffusion accommodation coefficient is added into the rcgularization term. Secondly, a self-adaptive parameter that varies with the number of iterations is added to the diffusion accommodation coefficient. Thus, the algorithm diffuses at a faster speed in the early iteration and slows down in the later iteration, and the restored image maintains a sharp edge. A large number of simulations show that the improved algorithm reduces the number of iterations and running time in the scratch and text removal, and the restored image has good visual effect.