基于散斑相关的数字激光散斑图像无失真压缩

Lossless Compression of Digital Speckle Images Based on Speckle Correlation

激光散斑图像压缩对降低数据存储量具有重要的意义。设计了一种激光散斑图像无失真编码器,它由激光散斑位移估计、像素预测和Golomb编码组成。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,并以预测模型为基础进行像素预测;最后,对预测误差进行Golomb编码。该编码器的主要特点包括使用数字散斑相关方法估计散斑位移,以及基于动态散斑相关函数极值的时间预测。实验结果显示,在压缩激光散斑图像时,激光散斑图像无失真编码器在压缩性能方面取得了较大的提高。

Compression of speckle images is significant to storage reduction of measurement systems. We propose a coder for lossless compression of laser speckle images, which is based on speckle displacement estimation, temporal prediction and the Golomb coding. Firstly, speckle displacements are estimated for each subblock. Next, according to correlation properties of dynamic speckle, we set up the prediction model which predicted current pixels model. Finally, prediction errors are coded by the Golomb coding. Key features of the proposed speckle image coder include the estimation of speckle displacement by digital speckle image correlation method and the prediction modeling based on the extremum of the dynamic speckle correlation function. Experimental results show that the proposed coder provides good improvement in compression coding efficiency of laser speckle images.