| Citation: | FENG Xiongbo，CHEN Xi，MIN Huina，et al.DR image enhancement of aero⁃engine guide vane based on improved CLAHE［J］.Journal of Aerospace Power，2022，37（7）：1425‑1436. doi: 10.13224/j.cnki.jasp.20210263
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In order to solve the problems of large dynamic range，low contrast，inconspicuous detail information，and difficulty in identifying defect areas in the image information detected by digital radiography （DR） of aero⁃engine guide blades，an improved adaptive histogram equalization algorithm with limited contrast was proposed.Contrast limited adaptive histogram equalization （CLAHE） was used to enhance the contrast of the DR image of the guide vane.Meanwhile，the Gaussian mask processing based on the spatial mean filter was introduced to reduce the image noise and extract the low⁃frequency information of the DR image.The high⁃frequency information of DR image was highlighted by difference of CLAHE enhanced image and the low⁃frequency information of DR image.Furthermore，a linear superimposing of CLAHE enhanced image and highlighted image high frequency information was employed to further improve the contrast of DR image and realize the enhancement of the DR image of the guide vane.In addition，the DR image enhancement effect was evaluated based on the basic spatial resolution of the image （SRB），signal⁃to⁃noise ratio （SNR） and gray average.Experimental results showed that the improved CLAHE algorithm can simultaneously increase the modulation depth value characterizing SRB correspondingly to the D13 double⁃filament wire from 49.17% to 56.08%，and the overall grayscale average value from 32 400.66 to 38 684.43，and the SNR of the No.02 micro crack defect was improved from 14.10 to 15.16.The result showed that the improved CLAHE algorithm not only improved the flat area contrast and highlighted the edge detail information，but also effectively improved visual effect of small defects in comparison with four classic aero⁃engine guide vane DR image enhancement algorithms such as adaptive histogram equalization （AHE）.
| [1] |
周莹.航空发动机涡轮叶片数字射线成像研究[D].南昌：南昌航空大学,2017.
ZHOU Ying.Research on digital radiography of aero⁃engine turbine blades[D].Nanchang:Nanchang Hangkong University，2017.（in Chinese）
|
| [2] |
赵俊皓.空心涡轮叶片残芯X射线检测技术[D].哈尔滨:哈尔滨工业大学,2018.
ZHAO Junhao.X⁃ray detection technology of hollow turbine blade residual core[D].Harbin:Harbin Institute of Technology，2018.（in Chinese）
|
| [3] |
王攀峰,赵书俊,王双玲,等.一种基于Retinex原理的DR图像增强改进算法[J].中国体视学与图像分析,2020,25（1）:57⁃64.
WANG Panfeng，ZHAO Shujun，WANG Shuangling，et al.An improved DR image enhancement algorithm based on Retinex principle[J].Chinese Stereology and Image Analysis，2020，25（1）:57⁃64.（in Chinese）
|
| [4] |
BZIMMERMAN J，PIZER S，STAAB E，et al.An evaluation of the effectiveness of adaptive histogram equalization for contrast enhancement[J].IEEE Transactions on Medical Imaging，1988,7（4）:304⁃312.
|
| [5] |
REZA A M.Realization of the contrast limited adaptive histogram equalization （CLAHE） for real⁃time image enhancement[J].Journal of Vlsi Signal Processing Systems for Signal Image and Video Technology，2004，38（1）:35⁃44.
|
| [6] |
陶佩,付青青,吴爱平.一种限制对比度的快速POSHE图像增强算法[J].长江大学学报（自然科学版）,2020,17（2）:104⁃111.
TAO Pei，FU Qingqing，WU Aiping.A fast POSHE image enhancement algorithm with limited contrast[J].Journal of Yangtze University （Natural Science Edition），2020，17（2）:104⁃111.（in Chinese）
|
| [7] |
刘轩,刘佳宾.基于对比度受限自适应直方图均衡的乳腺图像增强[J].计算机工程与应用,2008（10）:173⁃175.
LIU Xuan，LIU Jiabin.Breast image enhancement based on contrast⁃constrained adaptive histogram equalization[J].Computer Engineering and Applications，2008（10）:173⁃175.（in Chinese）
|
| [8] |
LOGANATHAN R，KUMARASWAMY Y S.Medical image compression with lossless region of interest using adaptive active contour[J].Journal of Computer ence，2012，8（5）:747⁃751.
|
| [9] |
KIM M ，CHUNG M.Recursively separated and weighted histogram equalization for brightness preservation and contrast enhancement[J].IEEE Transactions on Consumer Electronics，2008，54（3）:1389⁃1397.
|
| [10] |
孙冬梅,陆剑锋,张善卿.一种改进CLAHE算法在医学试纸条图像增强中的应用[J].中国生物医学工程学报,2016,35（4）:502⁃506.
SUN Dongmei，LU Jianfeng，ZHANG Shanqing.Application of an improved CLAHE algorithm in image enhancement of medical test strips[J].Chinese Journal of Biomedical Engineering，2016，35（4）:502⁃506.（in Chinese）
|
| [11] |
王红茹,李瑞,王佳.基于改进CLAHE的水下彩色图像增强算法[J].舰船电子工程,2019,39（11）:119⁃122,141.
WANG Hongru，LI Rui，WANG Jia.An underwater color image enhancement algorithm based on improved CLAHE[J].Ship Electronic Engineering，2019，39（11）:119⁃122，141.（in Chinese）
|
| [12] |
张文霞,王春光,王海超,等.改进的CLAHE无芒隐子草叶切片图像增强[J].农机化研究,2022,44（1）:25⁃30.
ZHANG Wenxia，WANG Chunguang，WANG Haichao，et al.Improved image enhancement of CLAHE without awn cryptocarp leaf slices[J].Journal of Agricultural Mechanization Research，2022，44（1）:25⁃30.（in Chinese）
|
| [13] |
刘陈瑶,胡梦竹,张龙飞.基于改进CLAHE的SF_6红外图像增强[J].光学技术,2021,47（1）:107⁃112.
LIU Chenyao，HU Mengzhu，ZHANG Longfei.SF_6 infrared image enhancement based on improved CLAHE[J].Optics Technology，2021，47（1）:107⁃112.（in Chinese）
|
| [14] |
İLK H G，JANE O ，İLK Ö.The effect of Laplacian filter in adaptive unsharp masking for infrared image enhancement[J].Infrared Physics and Technology，2011，54（5）:427⁃438.
|
| [15] |
徐艳丽,谭剑.基于非线性反锐化掩膜的DR图像边缘增强[J].中国医学物理学杂志,2010,27（4）:2013⁃2015.
XU Yanli，TAN Jian.DR image edge enhancement based on nonlinear unsharp masking[J].Chinese Journal of Medical Physics，2010，27（4）:2013⁃2015.（in Chinese）
|
| [16] |
RAMPONI G.A cubic unsharp masking technique for contrast enhancement[J].Signal Processing，1998，67（2）:211⁃222.
|
| [17] |
黄勇.基于双边滤波和改进CLAHE算法的低照度图像增强研究[D].湖南 湘潭:湘潭大学,2019.
HUANG Yong.Research on low⁃light image enhancement based on bilateral filtering and improved CLAHE algorithm[D].Xiangtan Hunan：Xiangtan University，2019.（in Chinese）
|
| [18] |
许蓉,王直,宗涛.基于改进高斯滤波的医学图像边缘增强[J].信息技术,2020,44（4）:75⁃78.
XU Rong，WANG Zhi，ZONG Tao.Medical image edge enhancement based on improved Gaussian filtering[J].Information Technology，2020，44（4）:75⁃78.（in Chinese）
|
| [19] |
刘凯,王晓勇,袁孟春.碳纤维缠绕发动机壳体数字射线DR成像检测图像质量控制[J].宇航材料工艺,2020,50（5）:76⁃82.
LIU Kai，WANG Xiaoyong，YUAN Mengchun.Image quality control of digital radiographic DR imaging inspection of carbon fiber wound engine shell[J].Aerospace Materials Technology，2020，50（5）:76⁃82.（in Chinese）
|
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