A New Holographic Inverse Filtering Method And Its Application 
To Restoration Of Degraded Remote Sensing Images 
Cao Haisheng and Chang Xiangqian 
Zhengzhou Institute of Surveying and Mapping 
No. 59 West Longhai Road, Zhengzhou, Henan 
China 
Commission I 
1! Introduction 
The sharpness and resolution of the remote sensing images 
are limited by the image motion. In recent years, it was  im-- 
proved by the forward motion compensation. But in many cases, 
there are also many linear motion blur images. The a posteriori 
methods of degraded pictures can be categorized under two 
heads: (a) digital, (b) optícal(analog). Digital methods, which 
are mainly computer assisted, have produced some excellent  re- 
sults and are commended for their ability to realize nonlinear 
transformations. But when the image to be processed has a large 
space-bandwidth product,digital techniques become difficult and 
expensive. This poses a serious limitation to the application 
of digital techniques. On the other hand,optical image process- 
ing is inexpensive and simple in comparision. But there are a 
serious limitations on the coherent optical image processing 
techniques: the low efficiencies, the small range of linear 
response of the filters and the coherent noise. To overcome 
this disadvantages, a new holographic inverse filtering system 
has been developed by the authors. The inverse filter is made 
by recording a hologram in the back of an attenuate mask 1/ |H| 
and then the filtering operation is done in multi-channel. The 
theoretical analysis and the experimental result are given. 
II. Description of the Optical System 
7 B.S. 
Lend] g, laser 
  
  
  
  
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Fig. 1: The experimental system of filter 
generating and image processing 
The optical experimental system is shown in Fig.1. The 65mw 
He-Ne laser is used as the coherent source: One bundle of beam 
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