摘要
以北京顺义区 32通道成像光谱数据为例 ,从数据的统计参数入手 ,分别从数据的方差、动态范围、相关性、直方图等方面分析研究噪声及特点 。
Noise elimination is one of the important step in image preprocessing. This paper, taking the imaging spectrometer data of Shunyi, Beijing as an example, deals with the research on noise analysis and elimination. Statistical method, combined with image processing technique, is used to analyze the existence and feature of noise. There are two types of noise in imaging spectrometer image of Shunyi. One type takes the form of speckles which exist in all the channels at random. The other type takes the form of strips which distribute in dark objects such as river and pond. There are different types noise in remote sensing imagery which influence the quality of image along the scanning direction and appear only in channel 18,19,20 and 21. The noise is eliminated by different methods according to the feature of noises. The speckle noise is eliminated by median filler quite well. While the second type noise is very special and can not be eliminated by conventional method. Therefore, a local neighboring algorithm is developed to eliminate it. The procedure is: automatically searching the noise along the line of image, when some pixel meets the demand of limit preset, replace its grey value by the average value of 5×5 pixel matrix in neighbor with uniform value. In this way the special noise can be eliminated effectively without damaging the raw data because the algorithm don't perform any processing on normal pixels. It can be seen from the processing result of study area that the proposed method is effective in analyzing and eliminating noise of imaging spectrometer data.
出处
《干旱区地理》
CSCD
北大核心
2001年第1期9-14,共6页
Arid Land Geography
