为实现工业产品的可追溯性,直接将条码加工在零件表面的直接零件标识(Direct Part Marking,DPM)技术,在国内外受到了越来越多的关注。对于金属零件,由于其具有较高的反光性,由相机捕获的金属表面的条码图像常常产生局部高光现象,影响条...为实现工业产品的可追溯性,直接将条码加工在零件表面的直接零件标识(Direct Part Marking,DPM)技术,在国内外受到了越来越多的关注。对于金属零件,由于其具有较高的反光性,由相机捕获的金属表面的条码图像常常产生局部高光现象,影响条码的正确读取。为此,针对金属表面激光标刻二维条码出现的局部高光现象,提出了基于五步重构模型的条码重构法,以重构高光区域的条码信息。对获得的条码图像进行倾斜校正,使"L"型实线边界位于图像左下角,对条码进行网格划分实现各个模块的定位。基于Modified Specular-Free(MSF)图像对高光区域进行检测。采用五步重构模型对条码的各个模块进行数值填充,对条码进行读取。实验表明,该算法能达到去除金属表面上条码局部高光的目的,并取得了较高的识读正确率。展开更多
Reversible data embedding is becoming a very important issue in securing images transmitted over the Internet, especially in dealing with sensitive images such as those created for military data and medical data. Base...Reversible data embedding is becoming a very important issue in securing images transmitted over the Internet, especially in dealing with sensitive images such as those created for military data and medical data. Based on the relationships between pixels and their neighbors, we propose a reversible data embedding scheme to embed hidden messages into an original image. In our proposed scheme, a two-layer data embedding approach is used for our proposed data embedding phase. Layer-1 embedding is used to hide secret data. Layer-2 embedding, which is an embedding variant of the proposed layer-1 embedding, is used to hide side information, such as the parameters required to restore the marked image. In our layer-1 embedding, the value of an embedded pixel is determined according to a predetermined threshold and the relationship between the pixel and its neighbors. In our layer-2 embedding, the similar data embedding concept is expanded to the block-based. Experimental results provide supportive data to show that the proposed scheme can provide greater hiding capacity while preserving the image quality of a marked image in comparison with previous work.展开更多
激光直接零部件标识(Laser Direct Part Marking)技术是一种在工业环境中证实可行,可实现高度自动化且绿色环保的标识技术,已经成为工业产品追溯中产品标识的首选手段。本文基于控制灵活、激光参数调节范围更大的MOPA(MOPA,主控振荡器...激光直接零部件标识(Laser Direct Part Marking)技术是一种在工业环境中证实可行,可实现高度自动化且绿色环保的标识技术,已经成为工业产品追溯中产品标识的首选手段。本文基于控制灵活、激光参数调节范围更大的MOPA(MOPA,主控振荡器的功率放大器)激光标识设备,按照ISO/IEC TR 29158条码技术标准,开展激光加工参数(如激光峰值功率、激光单脉冲能量、激光功率、填充间隔、扫描速度等)对激光直接标识(Direct Marking,DM)码质量(如条码等级、对比度、打印伸缩等)影响的研究。通过优化激光加工参数,实现了在AL2024材料表面标识高质量DM码的激光标识工艺。展开更多
文摘为实现工业产品的可追溯性,直接将条码加工在零件表面的直接零件标识(Direct Part Marking,DPM)技术,在国内外受到了越来越多的关注。对于金属零件,由于其具有较高的反光性,由相机捕获的金属表面的条码图像常常产生局部高光现象,影响条码的正确读取。为此,针对金属表面激光标刻二维条码出现的局部高光现象,提出了基于五步重构模型的条码重构法,以重构高光区域的条码信息。对获得的条码图像进行倾斜校正,使"L"型实线边界位于图像左下角,对条码进行网格划分实现各个模块的定位。基于Modified Specular-Free(MSF)图像对高光区域进行检测。采用五步重构模型对条码的各个模块进行数值填充,对条码进行读取。实验表明,该算法能达到去除金属表面上条码局部高光的目的,并取得了较高的识读正确率。
基金supported by the National Science Council Foundation under Grant No.NSC 98-2410-H-126-007-MY3
文摘Reversible data embedding is becoming a very important issue in securing images transmitted over the Internet, especially in dealing with sensitive images such as those created for military data and medical data. Based on the relationships between pixels and their neighbors, we propose a reversible data embedding scheme to embed hidden messages into an original image. In our proposed scheme, a two-layer data embedding approach is used for our proposed data embedding phase. Layer-1 embedding is used to hide secret data. Layer-2 embedding, which is an embedding variant of the proposed layer-1 embedding, is used to hide side information, such as the parameters required to restore the marked image. In our layer-1 embedding, the value of an embedded pixel is determined according to a predetermined threshold and the relationship between the pixel and its neighbors. In our layer-2 embedding, the similar data embedding concept is expanded to the block-based. Experimental results provide supportive data to show that the proposed scheme can provide greater hiding capacity while preserving the image quality of a marked image in comparison with previous work.
文摘激光直接零部件标识(Laser Direct Part Marking)技术是一种在工业环境中证实可行,可实现高度自动化且绿色环保的标识技术,已经成为工业产品追溯中产品标识的首选手段。本文基于控制灵活、激光参数调节范围更大的MOPA(MOPA,主控振荡器的功率放大器)激光标识设备,按照ISO/IEC TR 29158条码技术标准,开展激光加工参数(如激光峰值功率、激光单脉冲能量、激光功率、填充间隔、扫描速度等)对激光直接标识(Direct Marking,DM)码质量(如条码等级、对比度、打印伸缩等)影响的研究。通过优化激光加工参数,实现了在AL2024材料表面标识高质量DM码的激光标识工艺。
