基于灰度级分组的X光行李图像增强改进方法

针对低对比度X光手提行李图像在机场安检中容易产生高虚警或高漏警的问题，提出了一种基于灰度级分组的X光行李图像增强改进方法。首先应用离散小波变换对低、高能图像进行融合，然后通过分频处理得到低、高频图像，再分别采用基本灰度级分组和可选择灰度级分组方法实现增强。将本文方法与基于灰度级分组的增强方法、传统的直方图均衡方法进行比较，实验结果表明，本文方法能够有效地改善图像质量，提高图像的清晰度。

Improved X-ray Hand Luggage Enhancement Algorithm Based on Gray-Level Grouping

Aiming at the problem of high false alarm rate or high leakage alarm rate caused by poor quality of lowcontrast X-ray carry-on luggage images in airport security, an improved enhancement scheme based on GLG （gray-level grouping） is proposed in this paper. First, low and high energy images are fused with discrete wavelet transform. Then the methods of basic GLG and selective GLG are applied to the low-frequency and high-frequency images respectively ,which are obtained by frequency-division processing. Experimental results show that the proposed algorithm can improve image quality more effectively compared with the GLG and histogram equalization.