Citation: | Ji Y N, Li H F, Liu X. Image segmentation learning method for large field single lens computational imaging system[J]. Opto-Electron Eng, 2022, 49(5): 210371. doi: 10.12086/oee.2022.210371 |
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This paper presents an improved and optimized scheme for a large field of view single lens computational imaging system. In 2018, Peng Y F et al. proposed a single-lens computational imaging system with large field of view. This system solved the problem that the field of view of a single-lens computational imaging system could only be limited to 10 degrees. However, we noticed that after adopting the mixed PSF method of Peng Y F et al., the PSF learned by the network was not actually the accurate PSF of the image. This PSF error would have a bad effect on the final network output, resulting in the degradation of the quality of the restored network image. In order to solve the above-mentioned problem and make the imaging results of wide-field single-lens computational imaging system have better quality for human eyes to see, we proposed a processing method for wide-field PSF and its corresponding image training idea. Firstly, we divided the image into two parts, including the center and edge areas, according to the field of view. The center part corresponds to the field of view within 10 degrees, and the edge part corresponds to the field of view between 10 degrees and 53 degrees. In order to avoid segmentation traces after splicing, we adopted a segmentation method that can leave a gaussian gradient boundary. Then, the segmented images were made into two training sets, which were put into different networks for training. Under this situation, the PSF after the network training would be closer to the real PSF in the picture, which would greatly reduce the influence of PSF error, so that the quality of network training results would be better. After the training, the image to be restored was divided into two parts by the same method, and then the two parts of the image were restored in the corresponding neural network respectively. Finally, the output results of the two networks were spliced into a complete image to obtain the final result. For the same group of different pictures, we used the idea proposed by Peng Y F et al. and our new idea to restore and compared the results of the two methods. From the subjective perception of human eyes, the pictures obtained by using our new idea are more natural, clearer, and better than those obtained by using the methods of Peng Y F and others. In terms of objective evaluation indicators, our method is comparable to the method of Peng Y F et al. in terms of PSNR value. In terms of SSIM value, our method is much better than that of the Peng Y F et al. Therefore, in general, our idea does improve and optimize the large field of view single lens computational imaging system, and makes its imaging results higher quality and more suitable for human eyes.
Amplification of PSF with different fields of view[18].
The concrete implementation process of the new idea
Overall hardware system (sensors in the red box)
Image shooting and registration process
Sample of center partial dataset (shot image on the left, original image on the right)
Sample of edge partial dataset (shot image on the left, original image on the right). The reasons for leaving holes in the middle are detailed in the following article
Sample of test set after restoration, with two details highlighted in red boxes are listed below each image.
Sample of real pictures after restoration, with a detail selected in a red box is listed above or below each image.