[Analyzing the methods to smooth field reconstructed by algebraic reconstruction technique with spectroscopy].
The effects of filters and filtering methods on the field reconstructed by algebraic reconstruction technique (ART) is discussed with spectroscopy. The field to be constructed was simulated with numerical simulation technique. The effects of many kinds of filters and filtering methods on the field reconstructed by ART were analyzed with spectroscopy. The filters used included quarter, fifth, eighth averaging filter, fifth center filter, and third row, column filter. The filtering methods included filter being inserted in the iterating process or set at its end. The averaging filter mentioned above meant that the value was acquired from the average of the four data, named quarter averaging filter, and so on. The fifth center filter meant that the value was acquired from the center, the third one in ascendant or descendant sequence of the five data. As a result, the authors found that a larger difference existed in the effects of different filters and filtering methods on the reconstructed field. First, the field reconstructed by ART contained much big noise and needed to be smoothed. Secondly, the reconstructive accuracy declined much when an averaging filter, such as quarter, fifth or eighth filter, was only set at the end of iterating process. Thirdly, the accuracy could be improved a little with a quarter or eighth averaging filter inserted in the iterating process and activated according to iterating times. Forthly, a better accuracy could be obtained with a fifth center filter inserted in the iterating process than with a fifth averaging one inserted. Fifthly, the best result in this work was obtained with a fifth averaging filter and a fifth center one inserted in the iterating process and activated alternately according to iterating times.
Song
Yi-Zhong
YZ
Department of Information Physics and Engineering, Science Institute, Nanjing University of Science and Technology, Nanjing 210094, China.
Sun
Tao
T
Hu
Guo-Ying
GY
He
An-Zhi
AZ