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利用EPID图像金球位置自动跟踪算法研究 被引量:11
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作者 田龙 李明辉 胡逸民 《中国医学物理学杂志》 CSCD 2014年第4期5038-5042,共5页
目的:建立一种全新的算法,并利用EPID(Electronic Portal Imaging Device)图像实时读取预埋于体内金球的投影位置,自动重建金球在体内的投影位置坐标。方法:利用所编算法和Matlab软件进行EPID图像读取和处理金球投影位置并自动重建金球... 目的:建立一种全新的算法,并利用EPID(Electronic Portal Imaging Device)图像实时读取预埋于体内金球的投影位置,自动重建金球在体内的投影位置坐标。方法:利用所编算法和Matlab软件进行EPID图像读取和处理金球投影位置并自动重建金球在体内的位置坐标。即取通过图像处理和圆曲率识别各自获得的金球投影位置坐标集合的交集为真实的2D坐标,并依此反推到病人体内获得金球位于靶区当中真实的3D重建坐标。结果:本研究共进行了三组实验,每组为两个交角拍摄的EPID片。每组所有EPID片上的金球投影位置探测成功率分别为94.44%,93.75%,94.44%。算法重建的和利用CT扫描在TPS中重建的金球位置的三维坐标最大偏差为2.2 mm,最小偏差为0.1 mm。该算法于所使用的PC上完成一组(两张交角EPID图像)图像处理和重建的运行时间<1s。结论:对于多组相交角度拍摄的含金球投影位置的EPID图像,所编算法金球探测成功率比较高,平均为94%,算法重建出的靶区周围金球三维坐标同CT扫描重建出的坐标相比较,偏差在可以接受的范围内。但是该程序参数调节较复杂,而且EPID板接缝处剂量会影响探测成功率,还需要进一步开发自动参数计算程序和消除EPID板接缝处剂量影响。 展开更多
关键词 epid成像 图像处理 空间坐标重建 金球自动探测 实时位置验证
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Research on the Recovery of the Transported Static Image with Channel Errors
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作者 Liu Huai\|lin, Chen Shu\|zhen School of Electronic Information, Wuhan University, Wuhan 430072, Hubei,China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第3期297-301,共5页
A discussion is presented to gain the relationship between the original image and the reconstructed image while errors are mixed with the DCT data of the original image for the transmission. We can find the wrong reco... A discussion is presented to gain the relationship between the original image and the reconstructed image while errors are mixed with the DCT data of the original image for the transmission. We can find the wrong reconstructed blocks, locate blocks, which are most likely to contain errors and eliminate errors. The method needs no channel error protection, needs no verifiable bits, and needs no extra bandwidth. Experimental results are provided in the end. 展开更多
关键词 key words DCT IDCT reconstructed image CONTINUITY
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Algorithm of the Real-Time Extraction Image for Vehicle
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作者 LIU Quan HUANG Guo sheng 《Wuhan University Journal of Natural Sciences》 EI CAS 2000年第2期178-180,共3页
An algorithm applied to a real-time extraction image of vehicle is introduced. The algorithm include an image processing with a binarzation method, image grab for a vehicle with high speed, character isolator one by o... An algorithm applied to a real-time extraction image of vehicle is introduced. The algorithm include an image processing with a binarzation method, image grab for a vehicle with high speed, character isolator one by one, and neural network algorithm. The techniques include vehicles sensing, image garb control, vehicle license location, lighting and optic character recognition. The system is much more robust and faster than the traditional thresholding method. 展开更多
关键词 key words image processing target extraction BINARIZATION neural network
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Minimum Inductance Optimal Design for the Gradient Coil
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作者 Chen Yin ping, Zhu Guo qiang School of Electronic Information, Wuhan University. Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第3期302-306,共5页
In MRI (Magnetic Resonance Imaging), a crucial role of gradient coils is to image organism, meanwhile the inductance of the coils determines the speed of imaging. So it is of great importance to optimize designs of th... In MRI (Magnetic Resonance Imaging), a crucial role of gradient coils is to image organism, meanwhile the inductance of the coils determines the speed of imaging. So it is of great importance to optimize designs of the gradient coils. The target field approach is an effective method to design the gradient coils. Having applied this method and performing many numerical tests, we achieved the designs of thex ?,y ?,z ? in which the inductance and resistance of the coils also meet the requirements. 展开更多
关键词 key words magnetic resonance imaging LINEARITY target field Fourier transform
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