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详细分析了钢结构中节点图纸的消隐规则,把消隐的工程规则归纳为虚线的显示,并结合简化的实体布尔运算算法,提出了隐藏度和半隐藏度的概念,较好地解决了工程图纸中虚线的生成问题。 相似文献
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本文引入了一种梯形邻接图的图形表示方法来表达工程图纸中的线图形及其几何拓扑关系,并在此基础上提出了一种基于单次逐行扫描、梯形轮廓匹配、从轮廓提取矢量的工程图纸矢量化算法。这种算法能有效地提取出与原图保持较好一致性的图形矢量,具有处理速度快、内存需求小、矢量化效果好、特别适合丁大幅面图纸的矢量化等特点。 相似文献
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为实现二维工程CAD图纸矢量化,提出一种基于对象图例及其拓扑关系识别的矢量化方法。该方法首先针对对象图例的几何属性,提出基于HOG(Histogram of Gradient)和SVM(Support Vector Machine)的多类对象图例分类方法,然后通过提取对象的环形分割特征识别子类对象图例,接着利用基于连通域标记方法实现对象图例拓扑关系的识别。结果表明,本文算法能够有效识别图纸中的对象及其拓扑关系,对于图纸中常见的图例线条断裂、模糊等问题具有鲁棒性。基于本文算法提取的对象几何和拓扑信息可以为后续的图纸矢量化奠定基础,相关关键技术的探索性研究对后续工程图纸矢量化研究具有一定启发性。 相似文献
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针对企业在设计创新过程中大量采用已有计算机辅助设计(CAD)图纸进行设计重 用的情况,提出了一种基于哈希的二维工程 CAD 图纸检索方法。首先基于环形分割算法提取 工程 CAD 图纸中每个组件对象几何特征;基于传统 LBP 算子提出了一种局部拓扑矢量量化模 式(T-LVQP),实现对各个组件拓扑特征的提取;然后基于协方差描述符融合几何特征和拓扑特 征,通过 LBG 算法将所有组件按照几何特征分组后得到工程 CAD 图纸的特征向量表达;最后 通过迭代量化哈希算法生成图纸的哈希序列。实验结果表明,该算法检索速度快、准确度高, 对于二维工程 CAD 图纸具有较好的检索效果。 相似文献
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提出了一种新的快速有效的低分辨率SAR图像自动道路提取算法。算法使用道路特征检测算子检测道路边缘,利用一系列模板进行边缘像素的标定和短线段的连接,最后使用动态规划技术进行道路曲线段的连接。使用低分辨RadarSat SAR图像进行实验,实验结果证明了该算法的有效性。 相似文献
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《模式识别与人工智能》2005,18(5)
提出了一种简单实用的步态识别算法.该算法使用背景减除的方法检测人的行走运动.利用步态的周期性,选取步态图像序列中一个步态周期作近似时空切片处理,提取出步态特征向量.通过经典的PCA方法进行特征空间的计算,提取低维的步态特征.以欧氏距离作为度量,使用标准ENN分类器用于识别.在两个不同数据库上的仿真实验取得了较令人满意的实验结果.实验结果表明本文提出的算法具有对噪声、阴影及背景与前景灰度差别小等问题不敏感和计算代价小等优点. 相似文献
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连通区域提取算法研究 总被引:13,自引:0,他引:13
左文明 《计算机应用与软件》2006,23(1):97-98
常见的连通区域提取算法是针对四连通区域的。本文分析了几个相关的算法,并指出其优劣点,提出了一个八连通区域提取算法。首先按照一定的标号规则扫描图像,得到一定数量的连通区域;然后针对同一区域内标号不一致的情况进行处理即得到最终处理结果。实验结果表明此方法能有效地提取八连通区域,故可用于连通区域复杂的图像如签名的分块处理中。 相似文献
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Zhao Ming 《计算机科学技术学报》1995,10(1):2-14
This paper presents an algorithm for extracting lines from hand drawings.It starts from contour pixel tracing,fits them into contour segments,and then extracts skeleton lines from the contour segments.The algorithm finds all contours in one scan of the input matrix without detecting and marking multiple pixels.In line extraction,the method Elastic Contour Segment Tracing is proposed which extracts lines by referring to the contour segments at both sides,overcoming noise and passing through blotted areas by fitting and extrapolation. Experiments on free hand mechanical drawings,sketches,letter/numerals,as well as Chinese characters are carried out and satisfactory results are achieved. 相似文献
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Geusebroek Jan-Mark Smeulders Arnold W.M. Geerts Hugo 《International Journal of Computer Vision》2001,43(2):99-111
The extraction and interpretation of networks of lines from images yields important organizational information of the network under consideration. In this paper, a one-parameter algorithm for the extraction of line networks from images is presented. The parameter indicates the extracted saliency level from a hierarchical graph. Input for the algorithm is the domain specific knowledge of interconnection points. Graph morphological tools are used to extract the minimum cost graph which best segments the network.We give an extensive error analysis for the general case of line extraction. Our method is shown to be robust against gaps in lines, and against spurious vertices at lines, which we consider as the most prominent source of error in line detection. The method indicates detection confidence, thereby supporting error proof interpretation of the network functionality. The method is demonstrated to be applicable on a broad variety of line networks, including dashed lines. Hence, the proposed method yields a major step towards general line tracking algorithms. 相似文献
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基于遗传算法的SAR图像道路网检测方法 总被引:4,自引:0,他引:4
提出了一种基于遗传算法的SAR图像道路网检测算法.该算法以道路在SAR图像中呈黑色直线状结构为基本出发点,首先检测线特征点以获取潜在道路点;接着利用基于每个连通区域上的Radon变换提取线基元;然后从图像上最长的线基元出发,以其为种子基元,在其周围确定一个搜索区域,用遗传算法选择与种子基元共线的线基元进行连接,并更新种子基元,直到完成所有的连接,得到候选道路段.为了使检测道路更准确,利用蛇模型调整道路段的位置,然后用道路的特征进行鉴别.最后检测道路的交叉点,完成整个道路网的检测.机载SAR图像的实验结果及定量分析均证明了该算法的有效性. 相似文献
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考虑到飞行器目标在整幅图像中所占的比例往往较小,且图像背景复杂,本文提出了一种基于机场区域提取的飞行器目标分割算法.该算法首先利用Hough变换检测直线的特性,定位机场跑道和停机坪的位置,并结合教学形态学等图像处理技术去除了非机场区域;在提取机场区域后,再选择适当的阈值对图像进行分割,最后经过形态学去噪、小区域去除等步骤分割出飞行器目标.实验结果表明,该算法改进了以往机场区域提取算法保留候机楼等附属部分以及提取结果中存在机场区域以外区域的缺点,较好地实现了机场停泊飞行器目标的分割,为下一步准确识别飞行器类型奠定了基础. 相似文献
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A fast and robust algorithm for extracting line segments from an image through use of the Hough Transform is presented. The framework for our algorithm comes from the work of Illingworth and Kittler. We have extended their Adaptive Hough Transform algorithm to handle lines of arbitrary slope, multiple lines, and lines in very low signal to noise environments. We present our Modified Adaptive Hough Transform along with experimental results obtained with data from a tactile sensor. 相似文献
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This paper presents a morphology-based text line extraction algorithm for extracting text regions from cluttered images. First
of all, the method defines a novel set of morphological operations for extracting important contrast regions as possible text
line candidates. The contrast feature is robust to lighting changes and invariant against different image transformations
like image scaling, translation, and skewing. In order to detect skewed text lines, a moment-based method is then used for
estimating their orientations. According to the orientation, an x-projection technique can be applied to extract various text geometries from the text-analogue segments for text verification.
However, due to noise, a text line region is often fragmented to different pieces of segments. Therefore, after the projection,
a novel recovery algorithm is then proposed for recovering a complete text line from its pieces of segments. After that, a
verification scheme is then proposed for verifying all extracted potential text lines according to their text geometries.
Experimental results show that the proposed method improves the state-of-the-art work in terms of effectiveness and robustness
for text line detection. 相似文献
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We report on the development and implementation of a robust algorithm for extracting text in digitized color video. The algorithm first computes maximum gradient difference to detect potential text line segments from horizontal scan lines of the video. Potential text line segments are then expanded or combined with potential text line segments from adjacent scan lines to form text blocks, which are then subject to filtering and refinement. Color information is then used to more precisely locate text pixels within the detected text blocks. The robustness of the algorithm is demonstrated by using a variety of color images digitized from broadcast television for testing. The algorithm also performs well on images after JPEG compression and decompression, and on images corrupted with different types of noise. 相似文献
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基于特征段的正交矢量化及其符号识别方法 总被引:7,自引:0,他引:7
文中提出一种使用特征段的工程图矢量化方法,通过抽取图像中部分具有显著特征的行段建立特征矢量线段,经过延伸、合并求交等运算获取完整准确的矢量线.为避免毛刺、小弯度直线矢量化产生的奇异性,该研究运用正交双向矢量化的方法分别在X和Y方向对倾斜角小于45°和大于45°的直线分别进行特征段抽取.对粘连弯头短直线及端点符号识别也作了研究. 相似文献
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遗传算法与人工免疫算法对车间调度问题求解 总被引:1,自引:1,他引:0
针对求解job-shop调度问题中存在的易出现局部最优、效率低下的问题,提出了一种新算法。该算法 采用了一种评价种群过早收敛标准的方法,引进了新的加快遗传算法进化速度的交叉算子,最后设计了人工免 疫算法中疫苗的提取和接种方法,即基于加工机器的基因片断抽取疫苗方法和最后完工机器个体的接种方法。 通过实验证明该算法能够有效地解决易出现局部最优、效率低下等问题。 相似文献