| In inertial confinement fusion, plasma emission spectrum contains a lot of parameters state, such as ion temperature, rotating speed, density and ionization state. It can be concluded that the total amount of the plasma radiation, ion temperature, electron density, and plasma opacity through the intensity of X-ray energy spectrum and distribution. Therefore, how to obtain the plasma emission spectrum and then obtain the parameters of the plasma is the key problems that the Elliptical Crystal Spectrograph data acquisition and processing system solves. About the implementation of the Elliptical Crystal Spectrograph data acquisition and processing system, the main work of this paper are as follows:(1) We design and analysis detailly on the overall scheme of The Elliptical Crystal Spectrograph data acquisition system based on reading a lot of papers. Firstly, analyzing working principle of each part, and then introduce how to select the equipment. Finally, presenting the overall scheme of software and data processing method.(2) How to implement The Elliptical Crystal Spectrograph data acquisition system by software. In view of the firmware program design, it mainly introduces the framework that which can realize the basic framework program, the firmware library, USB descriptors and custom requests and the realization of the data transmission module. About the design of the driver, it contains the firmware download drivers, general program design methods and how to develop the information file. And for the application module, it mainly introduces equipment control function that commonly used and the method of application interface designing.(3) How to deal with the noise of image data. Based on the image data noise analysis, we found that the image data mainly inculed the impulse noise and gaussian white noise, however the median filter can effectively filter the impulse noise, wavelet transform has very good denoising effect on gaussian white noise.Therefore, this paper selects the combination of median filtering and wavelet transform filtering method to realize the image data denoising processing.(4) An improved algorithm of wavelet transform. In order to improve the image quality, on the basis of the basic theory of wavelet transform algorithm,this peper improves an variable coefficient of the customize neighborhood window of dual density dual tree complex wavelet transform algorithm. Firstly the noise image decomposes by the DDDTCWT which is implemented by applying four 2D Double-density Discrete Wavelet Transform(DDDWT) in parallel and distinct filter sets in the rows and columns. Then according to the difference of the joint coefficient-parent distribution in different scales and subbands, variable coefficient bivariate shrinkage function with adaptive selection of neighborhood window is adopted to process wavelet coefficients and to reconstruct the denoised images by the shrunk wavelet coefficients. Finally it will reconstruct the processing of wavelet coefficient. In addition, based on the Matlab simulation, it is verified denoising effect from the vision, signal-to-noise ratio and minimum mean square error. |
