利用亚像素位移估计提高激光散斑图像无失真压缩效率(英文)

Improved compression efficiency of lossless compression of laser speckle images by subpixel-accuracy displacement estimation

无失真图像压缩的目的是在保证不丢失任何信息的情况之下,用尽可能少的比特数表示图像。图像压缩对数据存储量的降低具有重要的意义。所设计的激光散斑图像无失真编码器由激光散斑位移估计、像素预测和哥朗布(Golomb)编码所组成。首先,估计散斑位移;然后,根据激光动态散斑相关函数设计预测模型,并以此为基础进行像素预测;最后,对预测误差进行Golomb编码。提出了一种改进的激光散斑图像压缩算法,并用实验对其进行验证和分析。改进的压缩算法通过亚像素散斑位移估计和双线性插值以提高压缩效率。实验结果表明,改进的压缩算法在压缩性能方面取得了较大的提高。

The purpose of lossless image compression is to represent an image signal with the bits as few as possible without loss of any information.Compression of speckle images has great significance to the reduction of storage requirement of measurement systems.The coder was composed of the speckle displacement estimator,the pixel predictor and the Golomb coding.Firstly,speckle displacements were estimated for each subblock.Next,according to correlation properties of dynamic speckle,the prediction model was set up and current pixels were predicted based on the model.Finally,prediction errors were coded by the Golomb coding.The improved algorithm was presented and analyzed by real experiments.The proposed algorithm improved compression efficiency based on speckle displacement estimation and the bilinear interpolation.The experimental results show that the improved coder can achieve a significant improvement on bit-rate.