CAJ | 학술논문

目的：数字化 X 线图像（DR）细节常被淹没、动态范围宽．本研究使用了一种基于加权红－黑小波（WRB）变换的增强方法解决这一问题．方法：原始 DR 图像先进行对数变换，然后对变换后的图像进行 WRB 分解得到各层的系数；通过设计的分段非线性子带系数操作函数，分别对各层系数进行处理，最后利用 WRB 反变换和处理过的子带系数重构出增强的图像．结果：WRB 方法测试原始 DR 图像，平均运行时间约为0.6 s；利用该方法对DR 图像进行增强后，图像细节显示效果和对比度均得到提升，且无光晕伪影产生；与一些常用的增强算法相比，用WRB 算法增强的图像信息熵和交叉熵指标均较优．结论：相比一些传统增强算法，基于加权红－黑小波变换的 DR图像增强方法具有明显优势，不仅能有效压缩图像动态范围，还增强图像细节和对比度．
목적：수자화 X 선도상（DR）세절상피엄몰、동태범위관．본연구사용료일충기우가권홍－흑소파（WRB）변환적증강방법해결저일문제．방법：원시 DR 도상선진행대수변환，연후대변환후적도상진행 WRB 분해득도각층적계수；통과설계적분단비선성자대계수조작함수，분별대각층계수진행처리，최후이용 WRB 반변환화처리과적자대계수중구출증강적도상．결과：WRB 방법측시원시 DR 도상，평균운행시간약위0.6 s；이용해방법대DR 도상진행증강후，도상세절현시효과화대비도균득도제승，차무광훈위영산생；여일사상용적증강산법상비，용WRB 산법증강적도상신식적화교차적지표균교우．결론：상비일사전통증강산법，기우가권홍－흑소파변환적 DR도상증강방법구유명현우세，불부능유효압축도상동태범위，환증강도상세절화대비도．
Aim:An enhancement algorithm based on weighted red-black wavelets (WRB)transform is presented to solve the problems of details buried and wide dynamic range in original DR images.Meth-ods:logarithmic transformation was first performed on the original DR images.then,the changed images were decomposed within the WRB architecture to get the wavelet coefficients of each layer.Furthermore a piecewise nonlinear coefficient operation function was designed to process the coefficients.In the end, the enhanced images were reconstructed by the inverse WRB transform.Results:The proposed algorithm is tested on the original DR images and compared with some other enhancement algorithms.The average running time of our algorithm is about 0.6 seconds and significantly faster than the other algorithms.U-sing our enhancement algorithm,both of the details and local contrast of the DR images are promoted, meanwhile no halo artifacts have been produced in the enhanced images.Furthermore,the information entropy and cross entropy indices of our algorithm are better than that of the other algorithms.Conclu- <br> sion:The proposed enhancement algorithm is an effective and efficient method for compressing image dy-namic range,enhancing image details of the original DR images.