CAJ | 학술논문

DEM数据具有不稳定、相关性差的特点,用离散小波变换对格网DEM数据进行压缩处理时,其边界问题将更为突出,主要表现在边界失真非常严重.这种现象不可避免地导致重建DEM数据精度的损失严重.为了最大限度地减弱边界问题的影响、提高压缩比,在进行格网DEM数据压缩时,作者将二维离散小波变换的边界问题转换为一维离散小波变换的边界问题,大大减小了边界失真区域,提高了重建DEM数据的精度.进而,用相应的算法进行了DEM压缩实验, 结果表明:可获取高压缩比且高精度的重建DEM数据.
DEM수거구유불은정、상관성차적특점,용리산소파변환대격망DEM수거진행압축처리시,기변계문제장경위돌출,주요표현재변계실진비상엄중.저충현상불가피면지도치중건DEM수거정도적손실엄중.위료최대한도지감약변계문제적영향、제고압축비,재진행격망DEM수거압축시,작자장이유리산소파변환적변계문제전환위일유리산소파변환적변계문제,대대감소료변계실진구역,제고료중건DEM수거적정도.진이,용상응적산법진행료DEM압축실험, 결과표명:가획취고압축비차고정도적중건DEM수거.
Due to the instability and less relativity of DEM data, the boundary problem in discrete wavelet transform becomes more outstanding and kittle when compressing grid DEM data with DWT, which mainly indicates the distortion degree appears very severe. This phenomenon will inevitably lead to serious loss of the precision of reconstructed DEM data. In order to utmost weaken the influence of boundary problem and improve the compression ratio, the boundary problem of two-dimensional DWT was transformed into the boundary problem of one-dimensional DWT, which can enormously diminish the area of boundary distortion and greatly improve the precision of the reconstructed DEM data, then the corresponding algorithm was proposed. Moreover, according to the algorithm, some experiments were made. The results prove that not only higher compression ratios but also reconstructed DEM data with high precision are achieved.