An Adaptive Smoothing Algorithm for Near-lossless Compression
用于图像近无损压缩的自适应平滑算法研究

The wavelet coefficients of an image will obtain higher performance of energy concentration after its high-frequency components are decreased by low-pass filters.This paper makes a study of the near-lossless compression scheme based on this principle.In order to make smoothing process more effective to improve compression rate of the above near-lossless compression scheme,this paper presents a novel smoothing algorithm,which can achieve better smoothing performance by adaptively select appropriate filter direction for every pixel according to its horizontal and vertical gradient intensity in the process of scan.Another remarkable advantage of this algorithm is that it can smooth the image according to given maximum amplitude error,then makes the accuracy of near-lossless compression adjustable.In addition,this algorithm is easy to implement for its low computation complexity.The experimental results with several standard test images demonstrate the effectiveness and adaptability of the presented algorithm in this paper.