基于尺度转折点的尺度转换方法研究

如何用一种向上的尺度转换方法使得一幅高分辨率的遥感图像经向上尺度转换后可以生成一幅低分辨率的遥感图像,并且使这幅新生成的图像所描述的地物空间关系、空间格局及破碎程度等信息与实际情况下该尺度下的信息保持一致,损失的信息量最少。如何找到这样一种尺度转换的方法是尺度问题中的核心部分,也是遥感中最终要解决的问题。本文一方面结合景观生态学中有关空间分析和尺度转换的方法及最近提出的基于直方变差图的尺度转换方法,对这些方法加以对比并分析了它们各自的优缺点;另一方面在直方变差图的基础上结合分形理论引入了尺度转折点这一概念。通过各个尺度转折点可以确定各个尺度域。。如何找到不同尺度域之间的尺度转换方法将是本研究的重点。本文拟采用的数据为互联网上的IKONOS天安门地区图像。

Study on the scale-transformation method based on turning point of the scale

How to find and make use of an up-scaling method which can transform the high-resolution image to the low-resolution and can keep the information such as the space relation,the spatial pattern and the fragmental degree which are expressed by the new image just like the reality is the core problem and must be solved in the field of remote sensing.On one hand,the paper compares some spatial analysis methods in the landscape ecology and analyzes their advantages and disadvantages.On the other hand,authors introduce the concept based on histo-variogram and fractal theory: the turning point of the scale. On the basis of the turning point,people can decide the scaling extent.In the same scaling extent,people needn't take into account the scaling effect.The method of the scale transformation is simple and the accuracy of prediction is much higher.How to find a feasible scale transformation algorithm between different scaling extents is the main idea in the study.Although Semi-variogram is much more intricate and full of ecological meaning,it shows good potentiality in this aspect.The image for the study is the scenes of TIAN-AN-MEN district of IKONOS with 4 m resolution.