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针对实际图像中采用传统Hough变换准确提取直线存在的问题,结合双阈值栅格除噪法,提出了一种改进的线段提取方法.该方法以Hough变换峰值参数逆变换提取线段特征,并将其连接成直线,在传统Hough变换算法的基础上增加了极大值线段的融合连接过程,去除伪峰值和峰值扩散引起的交叉线段等改进方法.实验结果表明:该方法能在干扰和噪声较强烈的实际图像中完整地提取出目标线段,对线段量化误差、断裂、线段信息丢失具有较强的鲁棒性.以Hough空间局部极大值所对应线段为主,以其邻域峰值点对应线段为补充的线段特征提取方法具有较高的准确性.本方法对视觉引导技术的实用化具有参考价值. 相似文献
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目的 为快速精确获取纸塑复合袋纠偏过程中的位置偏移和倾角信息,提出一种基于改进Hough变换的纸塑复合袋视觉定位算法.方法 首先通过大津法对平台上的纸塑复合袋图像进行分割,去除皮带部分;然后利用基于方差的差异化滤波方法对纸塑复合袋图像进行降噪处理,突出复合袋图像边缘;最后运用Canny算子获取纸塑复合袋边缘点,利用改进的Hough变换算法对纸塑复合袋4条边线进行直线提取,求解纸塑复合袋的中心位置和倾角.结果 改进算法在直线提取精度和耗时2个方面均优于传统Hough变换算法,获取纸塑复合袋位置和倾角只需0.335 s,耗时减少了76%.结论 改进算法的耗时满足纠偏定位要求. 相似文献
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为进一步提高邻域保持嵌入算法(NPE)在高光谱影像分类中的识别性能,提出一种改进的半监督邻域保持嵌入(SSNPE)算法。首先,该算法在NPE算法的基础上同时利用同类标记样本和邻域未标记样本获得数据的邻域嵌入结构。然后,通过增加近邻标记样本的权重加大降维数据的鉴别性。最后,通过利用k近邻分类器(KNN)对样本进行分类得到该算法在数据集上的分类性能。在Urban、Indian高光谱影像数据集上的实验结果表明,改进的算法的分类精度相比其他算法提高了约8.3%、6.2%以上,分类性能上有了较为明显的提高。 相似文献
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目的 发动机缸套内面网纹角直接影响到发动机的性能,为了高效准确地检测出内纹角,舍弃残次品,拟研究网纹夹角的检测方法。方法 采用邻域运算和自适应中值滤波对网纹图像进行图像增强,达到去除噪声和保留细节的双重效果;然后对其进行边缘分割处理,得到边界分明的边缘图像;再对其进行二值化,以减少Hough变化所用时间;最后提出一种基于Hough变换与清零法相结合的直线提取算法,并根据提取的直线特征计算网纹角。结果 实验结果表明,基于所提算法检测出来的夹角,对比传统方法和国外通用的仪器,平均检测误差降低为0.43%。结论 所提算法具有夹角误差小、准确度高、用时少等优点,能代替昂贵的进口仪器。所提算法在直线检测和包装条形码领域有较好的应用价值。 相似文献
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基于改进的Hough变换缸套内面网纹夹角检测 总被引:1,自引:1,他引:0
目的缸套内面网纹角是影响缸套性能的重要参数,为了在生产过程中快速准确检测出网纹角参数,剔除不合格产品,研究基于改进的Hough变换缸套内面网纹夹角检测方法。方法确定缸套图像的预处理算法,增强图像网纹特征,滤除次要信息;确定基于Canny算子的网纹特征边缘分割方法;确定基于改进的Hough变换网纹直线特征提取方法,通过计算提取直线夹角的平均值得到缸套网纹角值。结果试验表明,基于改进的Hough变换网纹角检测结果与进口仪器检测结果相比,平均误差为1.54%,检测精度高。结论提出的检测算法可准确识别缸套内表面网纹角,能很好地代替传统人工复膜检测和昂贵的进口检测仪器,满足工业现场自动检测的需要,提高了检测的效率和精度,降低了检测成本。 相似文献
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图像去噪是图像处理中的一个重要环节。基于均值滤波和中值滤波的经典算法,结合数字图像处理技术,以拍摄的直升机机场跑道路面裂纹图像作为研究对象,提出了一种改进的加权均值滤波算法,并通过仿真给出了试验效果图及数据结果。结果表明:改进的加权均值滤波算法较传统均值滤波能更好地保护图像的细节,失真小,在去除噪声的同时较好地保留边缘等细节信息,降低了图像处理后的模糊化程度,优于经典的滤波算法。该研究为机场跑道路面裂纹图像检测提供了一种新方法。 相似文献
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本文分别在现场以及试验室内研究了某机场跑道混凝土出现严重的开裂和剥落现象的原因。碱集料反应以及冻融循环均会导致开裂和剥落,通过XRD、岩相分析以及集料的碱活性检测排除了发生碱集料反应的可能性。采用快冻法测试了机场跑道现场钻取的芯样混凝土的抗冻性。同时借助于显微镜、SEM、MIP分析了损伤混凝土的微观结构,揭示出跑道混凝土的损伤与抗冻性较差有关,并讨论了改善严酷地区混凝土耐久性的措施。 相似文献
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Greg White 《International Journal of Pavement Engineering》2017,18(7):567-577
Two runways were resurfaced with 50–60 mm of typical airport asphalt at the same airport. One runway surface performed well while the other exhibited a lack of resistance to cyclic shear stress under heavy aircraft braking. Both runways had the same hydrated lime filler and coarse aggregate source. The fine aggregate (dust) used to manufacture the two runway surfaces was obtained from two different basalt quarries. The dust associated with the poorly performing asphalt contained a potentially detrimental clay mineral (Hisingerite). It was subsequently determined that the crude oil used to manufacture the feedstock for the acid-modified binder also changed at the transition from one runway to the other. The changes in dust and binder were confounded. A combination of viscosity testing and performance-based multiple stress creep recovery (MSCR) testing determined that the two runway binders responded significantly differently to shear stress and aged differently with sample storage time. The differences were magnified at higher temperatures. Further, mastic samples were manufactured from binder associated with both feedstocks, in combination with dust from both quarries. MSCR testing of mastic indicated that the dust containing significant Hisingerite had no adverse impact on the mastic response to shear stress. The change in binder feedstock was concluded to be the root cause of the lack of resistance to cyclic shear stress observed in one runway surface. This occurred despite all batches of binder meeting the viscosity-based Australian specification for paving grade bitumen. The specification has no mechanism to prevent similar changes in bitumen feedstock affecting airport bitumen performance in the future. Incorporating performance-based testing in the Australian bitumen specification is recommended. 相似文献
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Aircraft stands and runways at airports are critical airport resources for aircraft scheduling and parking. Making use of limited apron and runway resources to improve airport efficiency is becoming increasingly important. In this paper, we study a realistic Aircraft Scheduling and Parking Problem (ASPP) with the goal of simultaneously determining the takeoff and landing time of each aircraft with consideration for wake vortex effect constraints and parking positions in the limited parking apron at a target airport. The objective of the ASPP is to minimise the total service time for aircraft. We developed a mixed-integer linear programme formulation for the ASPP. A novel improved bottom-left/right strategy is applied to construct solutions and a Hybrid Simulated Annealing and Reduced Variable Neighborhood Search (HSARVNS) is proposed to identify near-optimal solutions. Numerical experiments on randomly generated ASPP instances and on a large set of benchmarks for a reduced version of the ASPP (i.e. the classical Two-Dimensional Strip-Packing Problem (2D-SPP)) demonstrate the effectiveness and efficiency of the proposed approach. For the ASPP, HSARVNS can find optimal solutions for small instances in a fraction of a second and can find high-quality solutions for instances with up to 250 aircraft within a reasonable timeframe. For the 2D-SPP, the HSARVNS can find optimal solutions for 32 of 38 tested benchmarks within 90 s on average. 相似文献
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At an airport, the information of the number and positions of airplanes is very important for the applications of air navigation. Especially, the information from airplane extraction and identification is significant in both civil and military remote sensing. In this paper, according to the characteristics of airplanes and airport in satellite remote sensing images, a new airplane image segmentation algorithm is proposed based on improved pulse-coupled neural network (PCNN) with wavelet transform, and airplane identification algorithm is carried out by using modified Zernike moments. Firstly, for an original image, a PCNN model is improved and then used to do image segmentation by combining the wavelet transform. Then, in order to reduce the number of irrespective targets in the image and increase the processing speed, the airplanes in the original image are roughly detected on the characteristics of the segmented object contour geometries. Finally, the Zernike moments are modified and then applied to identify the roughly detected airplanes accurately. By comparing to the five traditional image segmentation algorithms for the same airplane images, the testing results show that the improved PCNN image segmentation algorithm can segment and detect airplane regions at an airport accurately at a high recognising rate and with high recognising stability, and it is not affected by the image shadows and rotations. 相似文献
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The authors have modelled some of the effects caused by the detonation of chemical explosives in a subgrade under a cement concrete runway. It was assumed that, although the subgrade between the underground cavity (camouflet) and the runway was disturbed, the runway retained its original position and did not heave or crack.This article considers a series of possible materials that could be used to fill and stabilise the camouflet to effect a rapid and long-term runway repair. The authors found that the use of a material to fill a camouflet cavity did not have a significant effect on reducing runway surface displacements. Also there was no infill material that would increase the runway and subbase life for all load cases. The use of a suitably designed polystyrene infill gave the best results. 相似文献