Multiscale X-ray image contrast enhancement based on limited adaptive histogram equalization

2013 ◽  
Author(s):  
Shibin Wu ◽  
Qingsong Zhu ◽  
Shaode Yu ◽  
Qi Li ◽  
Yaoqin Xie
Keyword(s):  
Contrast Enhancement ◽  
Histogram Equalization ◽  
Image Contrast ◽  
X Ray ◽  
Adaptive Histogram Equalization ◽  
Image Contrast Enhancement

scholarly journals Study on Construction of a Medical X-Ray Direct Digital Radiography System and Hybrid Preprocessing Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Ren ◽  
Sheng Wu ◽  
Mijian Wang ◽  
Zhongjie Cen
Keyword(s):  
Contrast Enhancement ◽  
Digital Radiography ◽  
Histogram Equalization ◽  
Image Contrast ◽  
X Ray ◽  
Adaptive Histogram Equalization ◽  
Radiography System ◽  
Image Contrast Enhancement ◽  
Flat Field ◽  
Enhancement Algorithm

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.

scholarly journals Local Contrast Enhancement Utilizing Bidirectional Switching Equalization of Separated and Clipped Subhistograms

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Haidi Ibrahim ◽  
Seng Chun Hoo
Keyword(s):  
Contrast Enhancement ◽  
Histogram Equalization ◽  
Processing Technique ◽  
Image Contrast ◽  
Local Contrast ◽  
Image Contrast Enhancement ◽  
Enhancement Method ◽  
Equalization Technique ◽  
Histogram Bins ◽  
Almost All

Digital image contrast enhancement methods that are based on histogram equalization technique are still useful for the use in consumer electronic products due to their simple implementation. However, almost all the suggested enhancement methods are using global processing technique, which does not emphasize local contents. Therefore, this paper proposes a new local image contrast enhancement method, based on histogram equalization technique, which not only enhances the contrast, but also increases the sharpness of the image. Besides, this method is also able to preserve the mean brightness of the image. In order to limit the noise amplification, this newly proposed method utilizes local mean-separation, and clipped histogram bins methodologies. Based on nine test color images and the benchmark with other three histogram equalization based methods, the proposed technique shows the best overall performance.

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