Ren Yong, Wu Sheng, Wang Mijian, Cen Zhongjie
College of Communication Engineering, Chongqing University, Chongqing 400044, China.
Comput Math Methods Med. 2014;2014:495729. doi: 10.1155/2014/495729. Epub 2014 Jun 11.
We construct a medical X-ray direct digital radiography (DDR) system based on a CCD (charge-coupled devices) camera. For the original images captured from X-ray exposure, computer first executes image flat-field correction and image gamma correction, and then carries out image contrast enhancement. A hybrid image contrast enhancement algorithm which is based on sharp frequency localization-contourlet transform (SFL-CT) and contrast limited adaptive histogram equalization (CLAHE), is proposed and verified by the clinical DDR images. Experimental results show that, for the medical X-ray DDR images, the proposed comprehensive preprocessing algorithm can not only greatly enhance the contrast and detail information, but also improve the resolution capability of DDR system.
我们构建了一种基于电荷耦合器件（CCD）相机的医用X射线直接数字放射成像（DDR）系统。对于X射线曝光采集的原始图像，计算机首先执行图像平场校正和图像伽马校正，然后进行图像对比度增强。提出了一种基于锐化频率定位-轮廓波变换（SFL-CT）和对比度受限自适应直方图均衡化（CLAHE）的混合图像对比度增强算法，并通过临床DDR图像进行了验证。实验结果表明，对于医用X射线DDR图像，所提出的综合预处理算法不仅可以大大增强对比度和细节信息，还能提高DDR系统的分辨率能力。
