基于LUT的逆半调改进算法

An Improved Inverse Halftoning Algorithm Based on LUT

针对误差分散类半调图像,提出了一种基于查找表的逆半调改进算法。并用实验方法分析了训练样本大小、所选LUT模板与空值率之间的关系,且对LUT逆半调建表阶段出现空值时所采用的空值估计方法进行了改进;针对图像客观评价方法,提出一种寻找最高峰值信噪比的LUT模板选择算法。实验结果表明,利用所提出的优化LUT算法恢复的逆半调图像在人眼视觉以及峰值信噪比上有明显的提升。

For error-diffusion-halftone images, proposed an improved inverse halftoning algorithm based on LUT. Through experimental methods, analyzed the relationship between the number of training samples, the selected template of LUT and the null value rate, and improved the null-value-estimation method as null value appeared at the step of the LUT construction. In view of the objective assessment method for image, proposed a LUT template selection algorithm of looking for the highest PSNR. Experimental results show that using the improved LUT algorithm, the reconstructed inverse halftoning image in the human visual system and the PSNR has significantly improved.