The International Archives of the Photogrammetry , Remote Sensing and Spatial Information Sciences
The International Archives of the Photogrammetry , Remote Sensing and Spatial Information Sciences
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发表时间：
2004
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通讯作者：
Alex Dama;Andrew Calarcob;A. S. Walkera;Leica Geosystems
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作者：
Alex Dama;Andrew Calarcob;A. S. Walkera;Leica Geosystems
高性能扫描是数字摄影测量生产工作流程的常规部分。现代扫描仪提供的几何精度类似于分析绘图器和高质量的CCD传感器，能够忠实地以每个通道以12位的空中照片捕获信息，以提供出色的动态范围和音调设置。现代实践通常基于扫描正面或负面胶卷。最佳扫描仪的关键要求之一是高速光学分辨率，这是由于渴望在一夜之间完成滚动电影扫描的愿望。目前，由于其行业最快的扫描时间为每23 x 23 cm框架2分钟，因此可以在黑白摄影的Leica DSW600数字扫描工作站上完成此操作。还没有扫描仪可以使用500英尺的颜色卷。最近的改进试图将DSW上的这种性能扩展到颜色，同时提高图像质量和控制。 Leica Geosystems进行了许多针对这些目标的创新，包括：大格式12位传感器；新颖的LED照明系统，以增加光的量和均匀性，扩大照明区域以最大化扫描速度，降低成本并提高可靠性；舞台板和盖玻璃上的涂料以消除牛顿环；高性能线性编码器以优化几何完整性；软件改进，包括易用功能和JPEG2000。这些进步纳入了新模型，即DSW700，但大多数都可以通过定义明确的升级程序可用于现有扫描仪的用户。
High performance scanning is a routine part of the digital photogrammetric production workflow. Modern scanners offer geometric precision similar to analytical plotters and high quality CCD sensors capable of faithfully capturing the information in the aerial photograph at 12 bits per channel to provide excellent dynamic range and tonal set-up. Modern practice is typically based on scanning positive or negative roll films. One of the critical requirements of the best scanners is high optical resolution at very high speed, motivated by the desire to complete roll-film scans overnight. Currently this can be done on the Leica DSW600 Digital Scanning Workstation for black and white photography owing to its industry fastest scan times of 2 minutes per 23 x 23 cm frame. No scanner can yet do this for a 500 foot colour roll. Recent improvements attempt to extend this performance on the DSW to colour, while at the same time improving image quality and control. Leica Geosystems has undertaken a number of innovations aimed at these goals, including: large format 12-bit sensor; novel LED illumination system, to increase amount and uniformity of light, enlarge the illuminated area to maximize scanning speed, reduce cost and improve reliability; coatings on stage plate and cover glass to eliminate Newton Rings; higher performance linear encoders to optimise geometric integrity; software refinements, including ease-of-use features and JPEG2000. These advances are incorporated in a new model, the DSW700, but most are available to users of existing scanners by means of a well defined upgrade program.