DETERMINATION OF THE EFFECT OF THE EQUAL POWER SPECTRUM FILTER IN IMAGE RESTORATION
X. H. Yany, Xiujuan Zheng · Acta Astronomica Sinica · 2001
The effect of equivalent power filtering in image restoration is analyzed via simulated data. The original clear image is a gray one which consists of a series of rings centered at (0,0). For different rings, the gray values are changes stepwise and smoothly. In order to obtain a dirty image, the original one is first transformed via a linear space invariance system. Then, white noise is mixed to the image. The Equal Power Filter is adopted for the image restoration and the SNR is supposed to be constant. SNR and the defined gradient of the steps, in cooperation with the visual effect, are accepted to characterize the performance of image restoration. Investigating the quality of the restoration affected by the SNR, a conclusive result is thus obtained: a satisfactory restoration can be realized when the SNR15, while the effect of restoration becomes worse for the SNR15. In the condition of SNR5, the image is then completely not restorable. In addition, the restoration affected by the transfer function of the system is discussed in the paper. The present model of the Equal Power Spectrum Filter is confirmed by applying it to the observed image of objects. Finally, a typical application of the Equal Power Spectrum Filter is given.