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航空发动机涡轮叶片线阵CT断层图像轮廓提取与评价
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作者 俞梦倩 吴伟 +1 位作者 宋艳艳 王克广 《航空制造技术》 北大核心 2025年第22期160-167,共8页
工业CT线阵扫描是获取航空发动机涡轮叶片内部特征结构的重要方法,提取重建断层灰度图像轮廓是测量叶片壁厚等尺寸的关键步骤。由于目前常用像素级无监督评价方法存在提取边缘模糊,以及尺寸测量精度不高的问题,本文提出一种基于智能参... 工业CT线阵扫描是获取航空发动机涡轮叶片内部特征结构的重要方法,提取重建断层灰度图像轮廓是测量叶片壁厚等尺寸的关键步骤。由于目前常用像素级无监督评价方法存在提取边缘模糊,以及尺寸测量精度不高的问题,本文提出一种基于智能参数优化的数模匹配亚像素级轮廓提取算法。首先采用LBF几何活动轮廓模型提取边缘,在CAD模型上获取对应截面点云;然后通过OBB方向包围盒算法将两者坐标统一,以Hausdorff距离建立评价函数;最后基于蜣螂智能优化算法,对LBF模型中正则项系数等4个参数寻优,使得轮廓提取达到最佳。叶片CT断层图像测试结果表明,相对误差小于1.6%,相比于传统的Canny、Ostu以及Zernike等边缘检测算法,本文算法可以显著提高测量精度。 展开更多
关键词 航空发动机涡轮叶片 CT断层图像 LBF(Local binary fitting)模型 蜣螂优化算法(Dung beetle optimizer DBO) 方向包围盒(OBB)
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Automatic image segmentation method for cotton leaves with disease under natural environment 被引量:9
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作者 ZHANG Jian-hua KONG Fan-tao +2 位作者 WU Jian-zhai HAN Shu-qing ZHAI Zhi-fen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第8期1800-1814,共15页
In order to improve the image segmentation performance of cotton leaves in natural environment, an automatic segmentation model of diseased leaf with active gradient and local information is proposed. Firstly, a segme... In order to improve the image segmentation performance of cotton leaves in natural environment, an automatic segmentation model of diseased leaf with active gradient and local information is proposed. Firstly, a segmented monotone decreasing edge composite function is proposed to accelerate the evolution of the level set curve in the gradient smooth region. Secondly, canny edge detection operator gradient is introduced into the model as the global information. In the process of the evolution of the level set function, the guidance information of the energy function is used to guide the curve evolution according to the local information of the image, and the smooth contour curve is obtained. And the main direction of the evolution of the level set curve is controlled according to the global gradient information, which effectively overcomes the local minima in the process of the evolution of the level set function. Finally, the Heaviside function is introduced into the energy function to smooth the contours of the motion and to increase the penalty function Φ(x) to calibrate the deviation of the level set function so that the level set is smooth and closed. The results showed that the model of cotton leaf edge profile curve could be obtained in the model of cotton leaf covered by bare soil, straw mulching and plastic film mulching, and the ideal edge of the ROI could be realized when the light was not uniform. In the complex background, the model can segment the leaves of the cotton with uneven illumination, shadow and weed background, and it is better to realize the ideal extraction of the edge of the blade. Compared with the Geodesic Active Contour(GAC) algorithm, Chan-Vese(C-V) algorithm and Local Binary Fitting(LBF) algorithm, it is found that the model has the advantages of segmentation accuracy and running time when processing seven kinds of cotton disease leaves images, including uneven lighting, leaf disease spot blur, adhesive diseased leaf, shadow, complex background, unclear diseased leaf edges, and staggered condition. This model can not only conduct image segmentation of cotton leaves under natural conditions, but also provide technical support for the accurate identification and diagnosis of cotton diseases. 展开更多
关键词 local binary fitting model natural environment COTTON disease leaves image segmentation
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