具有宽度的线状物体的灰度增强

本文介绍一种对具有宽度的线状物体进行整体灰度增强的方法。它是利用付里叶变换的特点，将空域图象变换到频域中，然后对此频域图象进行方向滤波，再对滤波结果作反变换，最后在空域中只保留具有宽度的线状物体，从而达到整体灰度增强的目的。文中介绍了方向滤波的原理，以及实现的方法，最后给出了在航测照片的道路网自动识别中的应用实例。

Gray Enhancement of the Linear Objects with a Certain Width

This paper presents a method which enhances the gray scale of the linear objects with acertain width as a whole, It makes use of the characteristics of the Fourier Transform,andtransforms aspatial domain image into the frequency domain, in which the method operatesadirectional filtering to the image. Then the result of the filtering is operated in the inversetransform. Finally in the spatial tiomain there exists only the objects with a certain width,sothat it achieves the goal of gray enhancement. In the paper the principle of the directional fil-tering and the way of realization are introduced. And the application example in the automat-ic recognition of the road network of the aerial photograph is given.