共查询到20条相似文献,搜索用时 156 毫秒
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文章结合实验室建标的实际情况,主要针对建标过程中不确定度评定进行分析,探究在建标报告中进行不确定度分析背后隐藏的数学意义。 相似文献
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随着数字影像技术的迅猛发展,数字影像数据得到快速累积,数字影像管理技术越来越受到重视;本文针对当前数字影像管理技术面临的问题,系统研究了对象一关系数据库大对象(LOB)流式处理方法在数字影像管理技术上的应用,并结合实例,介绍了具体实现方法。 相似文献
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本文介绍了一个小型三维造型系统,着重叙述了作者独立完成的物体拼合以及显示输出子模块中的三维线框模型输出,同时介绍了该软件在制图课教学中的应用。 相似文献
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针对噪声严重的超声图像,提出了一种结合数学形态学和Level Set的分割方法。首先采用全变差模型进行图像滤波,再通过交互式区域选择和数学形态学方法获得感兴趣目标的二值化图像,并把该二值化图像轮廓作为水平集方法的初始曲线。改进隐式测地活动轮廓模型(GAC)中的边缘检测函数,增强了处理弱边缘的能力。分割结果表明,该方法能够准确地提取出目标轮廓,同时减少了迭代次数和运算时间。 相似文献
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工业雷管激光编码打标原理及安全性论述 总被引:3,自引:0,他引:3
文章对激光编码打标的原理进行分析,论述了工业雷管激光编码打标安全性问题,并阐述了对这些问题的认识,提出在做好安全防护前提下,激光用于工业雷管编码打标是可行的。 相似文献
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《成像科学杂志》2013,61(4):351-360
AbstractThis work describes the investigation into a new 3D capture method for acquisition and subsequent forensic analysis of bite mark injuries on human skin. When documenting bite marks with standard 2D cameras, errors in photographic technique can occur if best practice is not followed. Subsequent forensic analysis of the mark is problematic when a 3D structure is recorded in a 2D space. A 3D image capture and processing system might avoid the problems resulting from the 2D reduction process, simplifying the guidelines and reducing errors. This paper reviews current 2D and three 3D capture methods and proposes a series of benchmarks for system assessment. This is followed by a series of performance evaluations of the existing current 2D and two 3D methods. Further proposed solutions include the design of a system specification for the practical reproducible acquisition of bite mark injuries and a review of the validation process for forensic evidence presented to the courts. The result of this work is that a 3D system is required to produce the correct 3D data of a bite mark and suspect dentition for forensic analysis. Such a system should be practical and consistent if it is to replace the current de facto 2D systems. The MAVIS hardware, for example, can be considered a practical and consistent solution for producing the required 3D image of a bite mark for analysis; however, the MAVIS hardware cannot produce a satisfactory 3D image of a dental cast. At present, a laser scanner is required to produce satisfactory results of a dental cast. Angular distortion and errors created by the user in 2D image capture can hinder the digital measurement process. 3D capture therefore introduces less operator error in the form of angular distortion. 相似文献
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Robust image watermarking scheme against geometric attacks using a computer-generated hologram 总被引:6,自引:0,他引:6
Li J 《Applied optics》2010,49(32):6302-6312
Robustness against geometric attacks is one of the most important issues in digital watermarking. A novel geometric robust watermarking scheme that uses computer-generated holograms as the watermark is presented. To maintain imperceptibility and robustness, a quantization embedding algorithm is adopted to embed the mark hologram into the low-frequency subband of the wavelet-transformed host image. In the detection process, the geometric distorted watermarked images are recovered first by the proposed improved geometric correction method, which is based on the scale invariant feature transform, the invariant centroid, and the pulse coupled neural network. Then the mark holograms are extracted from the recovered images. In comparison with the traditional geometric estimation method, the suggested improved geometric correction method can estimate the geometric distortion parameters more accurately and needs less auxiliary information. Compared with other watermark schemes using digital holograms, the proposed method has the distinct advantage of robustness to geometric attacks. The experimental results demonstrate that the proposed method has good robustness to resist geometric attacks and common attacks including rotation, scaling, translation, image flipping, combined attacks, filtering, occlusion, cropping, and JPEG compression. 相似文献
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目的 为了实现空调包装箱上型号标记缺陷的实时动态检测,基于图像处理技术设计包装箱型号标记缺陷检测系统.方法 基于AM5728控制器设计控制系统硬件平台,主要包括控制单元、图像采集与处理单元、成像单元等,并进行实际测试研究.采用几个关键方法,包括图像增强处理、形态学、缺陷检测、动态阈值分割算法等,并根据包装箱型号标记图像特征选择配准区域,同时给出一种动态阈值分割算法,利用各种算法实现缺陷检测.结果 采集了250个包装箱条码样本,采用文中方法获取到了监测数据,正确率高达97.2%,漏检率为0.结论 该方法具有较高的可靠性、通用性,可实现包装箱型号标记的缺陷快速检测,解决了空调包装箱上的型号标记实时动态缺陷检测的实际工程问题. 相似文献
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一种用于印刷图像防伪的水印算法设计与实现 总被引:4,自引:4,他引:0
阐述了基于DCT变换域的数字水印理论和算法,并根据相关理论模型,提出了一种在离散傅里叶变换中实现的、可用于印刷品防伪的数字水印嵌入算法。研究表明与传统的LSB算法和Patchwork算法相比,该算法有较好的抗攻击能力。给出了系统的水印嵌入算法和水印提取流程设计的过程。实践证明,基于DCT变换域的数字水印算法能确保水印的不可见性,并保持较好的鲁棒性,实现了印刷图像载体数字版权的保护,并可检测出用此算法嵌入印刷图像中的不可见标记。最后通过实验验证了此算法的可行性、可靠性和有效性,为印刷品版权保护提供参考和借鉴。 相似文献
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