Imaging quality enhancement in binary ghost imaging using the Otsu algorithm

Abstract

A decline in imaging quality will occur when the sampling data of ghost imaging is recorded by binarization. Based on the Otsu binarization, a method named Otsu binary ghost imaging (OBGI) is proposed to enhance imaging quality. Both theoretical and experimental results show that, with an appropriate threshold value, OBGI can enhance imaging quality significantly when compared with ordinary binary ghost imaging, even providing better imaging quality than that of traditional ghost imaging. It is also shown the method is more applicable under the conditions of low-light level and with a complicated object.

Detail reconstruction in binary ghost imaging by using point-by-point method

“…During this process, the pseudo-thermal source was obtained by projecting a frequencydoubled pulsed Nd:YAG laser (λ=532nm and diameter D=6mm) onto a slowly rotating ground-glass disk. Firstly, we choose a simple double slit ( 128 of the information loss during the binary, while it can be improved by using OBGI [29]. Note that the reconstruction of the detail by the three methods is not good (see the part marked by the red circle).…”

“…The speckle pattern is optimized by OTSU binarization (see Fig. 2(c1)), so imaging quality of OBGI is better [29]. Unlike the above methods which use the same threshold to divide all pixels, point-by-point method provides the corresponding threshold of each pixel, and makes full use of the threshold of the adjacent pixel points, which makes some speckle with smaller size occur (see the part marked by the red circle in Fig.…”

“…During this process, the acquirement, storage and transmission of large amount of data can affect imaging speed. For this problem, binarization ghost imaging (BGI) is put forward [26][27][28][29]. Chen et.…”

“…While, imaging quality by BGI is poor than that by TGI because the binary process is inevitably accompanied by the loss of information. To solve this problem, the group of Guo proposed a scheme in which imaging quality can be improved effectively by adding suitable random noise to the raw data before quantization [28], and our group demonstrated experimentally that Otsu binary ghost imaging (OBGI) can achieve a better imaging quality when compared with TGI [29]. In fact, the detail reconstruction for imaging object in the two works is not good.…”

Improving the performance of ghost imaging via measurement-driven framework

“…Moreover, binary patterns refresh faster on the DMD, which is extremely important in real-time ghost imaging applications 44 . Different from the previous binary threshold selection strategies 49,50 , an effective binarization threshold is provided to quantize the sampling matrix. Let α > 0 be the binarization threshold, which is defined as the average of all non-zero elements of the optimized sampling matrix, then…”