In the infrared image segmentation, spectral clustering needs to calculate the similarity matrix between pixel points, the amount of data is large and the calculation is time-consuming. To solve this problem, an improved spectral clustering infrared image segmentation algorithm based on improved sparse matrix is proposed. The algorithm combines the feature of the whole image with the relationship between pixels, and then convinces the network to extract the infrared image feature information through convolution, and uses the selected feature information to construct the sparse similarity matrix, and completes the segmentation by combining the spectral clustering method. Experimental results show that this algorithm can effectively reduce the computational complexity of spectral clustering and effectively improve the segmentation result of the target area of infrared images.
The general scalar diffractive theory for Gaussian beam has been investigated. The two-zone and three-zone annular phase-only pupil filters are adopted to provide specific numerical descriptions of improvement of DOF, respectively. The simulated results show that the annular phase-only pupil filters can be used to control the DOF of the optical system. For the well designed filters they can help improve the DOF in the axial direction and increase the resolution in the transverse direction, simultaneously. However, the Strehl ratio of the optical system maybe decline and the side-lobe to peak intensity ratio will increase with the improvement of the DOF which is hard for the optical imaging. Comparison results show that the two kinds of three-zone annular phase-only pupils have the same impact on the control of the light intensity distribution.
The scalar diffractive theory for Gaussian beam has been taken into account to investigate the PSF of the focal plane. The simple slowly varying phase-only pupil filters are adopted to provide specific numerical descriptions to control the DOF of the optical systems. Simulated results of the continuous phase-only pupils in both axial and transverse directions have been presented. The impact of the structure parameters of pupil a and b on the performances of the light intensity distribution is discussed. Furthermore, some useful advices for the design of super-resolving pupils to increase DOF of the optical system based on Gaussian beam are given.