Reversible integer wavelet evaluation for DEM progressive compression

The DEM multi-scale representation, progressive compression and transmission based on integer lifting wavelet can eliminate the redundant data between resolutions for web-based spatial information system. Through experimental data and theoretical analysis, the 2/6 integer wavelet was found to be the most suitable transform for the DEM multi-scale progressive compression among the 14 reversible integer wavelet transforms compared. The 2/6 integer wavelet can obtain perfect accuracy performance in DEM multi-resolution data. In addition, it has low computing complexity and favorable compression performance. Two appraisal methods were innovatively proposed to better appraise the accuracy performance in different DEM resolution data. One is the mean distances measurement between two surfaces of different resolution DEM data. The other is the measurement of the terrain representation error's RMSE.