YH3D-6002系列动态四轮定位仪技术解析(三)

广角镜头:广角镜头是一种焦距短于标准镜头,视角大于标准镜头,焦距长于鱼眼镜头,视角小于鱼眼镜头的摄影镜头。广角镜头又分为普通广角镜头和超广角镜头两种。135照相机普通广角镜头的焦距一般为24～38mm,视角为60～84°;超广角镜头的焦距为13～20mm,视角为94～118°。由于广角镜头的焦距短,视角     

潜艇废气排放气泡视觉测量系统

潜艇废气排放时将在海水中引起气泡,这给潜艇的隐身带来困难。提出了一种基于计算机视觉测量技术的方法测量气泡的大小。介绍了在实验室模拟潜艇废气排放的原理和气泡视觉测量系统的关键技术,并据实验结果就气泡大小对潜艇隐身的影响进行了分析。     

交通图像在智能交通系统中的应用

介绍了交通图像的相关内容,包括其获得方式、交通参数的提取、图像的压缩方式及形式,针对交通图像在智能交通系统中的应用进行了相关讨论,如车牌检测和识别、闯红灯检测技术、超速检测技术、道路识别系统,提出了在处理过程中一些尚待解决的问题.     

A semi-fragile wavelet transform watermarking scheme for content authentication of images

A novel semi-fragile watermarking scheme for the content authentication of images using wavelet transform (WT) is presented in this paper. It is tolerant to the embedded wavelet image compression methods based on WT such as embedded zerotree wavelet (EZW), set partitioning in hierarchical trees (SPIHT) and embedded block coding with optimized truncation (EBCOT) in JPEG2000 to a pre-determined bit-plane, but is sensitive to all other malicious attacks. The image features are generated from the lowest-frequency (LF) subband of the original image as the embedded watermark. The watermark is embedded into the pre-determined bit-plane by adjusting the corresponding values in the given subband. In the process of watermarking authentication, we compare the image features generated from the LF subband of the received image with the embedded watermarking information (the image features of the original image) extracted from the pre-determined bit-plane in the given subband of the received image to decide whether the image is attacked maliciously or processed acceptably (the embedded wavelet compression). The most important advantage of our watermarking scheme is that the watermark information can be extracted from the watermarked image when detecting watermark, so the received image authentication needs no information about the original image or watermark. Experimental results prove the effectiveness of our proposed watermarking scheme.     

采用DDN线路实现“三合一”远程收费管理系统

本文介绍了宁连宁通公路管理处利用ＤＤＮ线路进行远程监控、ＩＰ电话以及数据通信的组网方案和系统结构，以及在公路收费监控中的实际应用情况。     

港口水域使用雷达的局限性及对策

针对部分驾引人员的雷达使用习惯,结合IMO雷达设备性能标准和港口水域船用雷达使用的实际情况,探讨在港口水域使用雷达时的注意事项。分析表明,在船舶密度极高的港口水域,雷达的避碰功能并不适用,雷达图像应进行适应性调节以应对特殊的航行环境。     

基于图像分析技术探析混凝土桥梁结构表面裂缝宽度检测

传统的人工检测方式下进行的混凝土桥梁结构表面裂缝检测耗费了较多的人力和物力,并且存在着较大的误差。在测量技术不断发展的前提条件下,基于图像分析的混凝土桥梁结构表面裂缝宽度检测凭借着其测量数据的精准度以及人力和物力资源的节约优势,得到了更多的重视和应用,主要对其进行分析。