基于DN值趋势面的成像光谱数据低信噪比波段修复研究

Study on a Method to Repair Low-ratio S/N Band of Imaging Spectrometer Data Based on the Trend-face of DN Value

针对利用成像光谱数据进行反射光谱重建时,因连续多波段低信噪比图象的噪声造成的影响问题,提出了一种基于低信噪比波段DN值趋势面的图象修复方法.该方法在准确估计修复图象DN值均值趋势面的基础上,通过引入能量比约束条件,将高度相关的邻近波段方差信号引入修复图象,从而不仅较好地消除了噪声对反射光谱重建的影响,而且改善了低信噪比波段参与合成的图象质量.实验结果表明,该方法以一种新的低通滤波思想实现了修复病态波段、恢复光谱特征这一应用目标.

With a consideration of the influence of consecutive multiple bands of images with a low signal to noise (S/N) ratio obtained from imaging spectrometer on the reconstruction of reflectance spectrum, an amending method is developed from the digital number (DN) value of trend-face of low S/N ratio band. On the basis of properly estimated the trend-face of DN average values, the highly correlated signal variances are introduced from adjacent band to amending band under the constraint condition of energy ratio of DN in this method. As a result, not only the influence of original noise band on the reflectance spectrum reconstruction is eliminated accordingly, but also the quality of composed images generated from low-ratio S/N band is improved by this amending method. The results show that the application aim of amending defect bands and restoring spectrum characteristics is realized with the new concept of lower-passfilter.