基于人眼视觉特性的ROI编码

Research on ROI image coding based on human visual specialties

研究了等级树集分割编码方法(SPIHT)在ROI图像编码中的应用。根据SPIHT编码方法的特性、ROI区域小波系数提升后整幅图像小波系数的特点及人眼视觉特性,提出改进算法。同时提出质量等级因子的概念并给出了其数学表达式。本文提出的改进算法可在保证ROI质量等级的同时提高整幅图像的主观效果。仿真实验证明了改进方法的有效性及质量等级因子的调节作用和其公式的正确性。

Set partitioning in hierarchical trees (SPIHT) was used to realize region of interest (ROI) image coding. Based on the characteristics of SPIHT, the properties of image wavelet coefficients after the coefficients associated with ROI were scaled up, and human visual specialties, a parameter of image quality (Q) and its formula were presented. Based on this, an improved algorithm was put forward, which could improve the subjective quality of image meanwhile ensure the quality of ROI. The experimental results show that the proposed method is effective and the formula of Q is correct, and we can choose Q to control the quality of ROI.