MTF estimation via BP neural networks and Markov model for space optical camera

The modulation transfer function (MTF) is one of the essential criteria of space optical camera. However, the traditional measurement methods of MTF are limited by precise equipment and test site. In this paper, a novel method is proposed to estimate the MTF of space optical camera via BP neural networks and Markov model. Utilizing this method, the MTF of space optical camera can be estimated only from the images taken by the camera without additional measurement equipment. The principle is to use the information extracted from known MTF images to train a BP artificial neural networks (ANN), and then use the BP ANN to estimate the MTF of space optical camera from remote images. In the meanwhile, the Markov model is used to correct the results estimated by ANN. The experiment results show that the MTF estimation average relative error at Nyquist frequency can further narrow to 5% via BP neural networks and Markov model, compared with 9% using only BP ANN.     

Science and taste. Painting, passions, and the new philosophy in seventeenth-century Leiden.

This article argues that the art collection owned by Franciscus dele Bo?, Sylvius, a professor of practical medicine at the University of Leiden from 1658 to 1672, gives insight into some aspects of the character and significance of the new philosophy in the midseventeenth century. Through his teaching, his advocacy, and his practice of the new experimental philosophy, Sylvius played a role in shaping and institutionalizing the practices of the new philosophy that spread throughout Europe in the late seventeenth and eighteenth centuries. Sylvius's house design and large painting collection also exemplified the consumption and taste of the northern Netherlands in the seventeenth century. An examination of both Sylvius's science and his taste can help us understand what was at stake for Sylvius and his contemporaries in their practice of the new philosophy. This article finds that Sylvius's taste and his science both involved practices of social distinction, demarcation, and control. Moreover, both were enmeshed in controversy about the epistemological status of knowledge gained through the senses and about the practices by which that knowledge was gathered.     

一种基于立方体的摄像机内参数标定方法

摄像机标定方法是计算机视觉的重要内容之一。提出了一种基于立方体的标定方法。该方法的模型为立方体,从3个或多个不同的方位摄取图像,由直径的正交关系获得3组正交灭点,从而线性的求出摄像机的5个内参数。模拟图像和真实图像实验表明,文章的自标定方法有较好的灵活性和较高的鲁棒性。     

DV摄像机应用技术

目前DV摄像机已成为大众消费产品,给学习、生活及娱乐带来诸多方便,大部分人因为对其性能了解不细,操作技能不熟,导致拍摄效果欠佳,如果能熟练掌握光圈、景深和运动镜头的使用技术技巧,就能拍摄出明暗合适、虚实相衬、动静结合的精彩作品。     

数码相机存储卡数据恢复一则

当数码相机存储卡的相片数据不见了之后,电脑用户可借助数据修复软件,如金山数据恢复专业版,将相片数据恢复。     

帧转移型CCD相机图像拖影研究

帧转移型面阵CCD相机因其诸多优点而得到了广泛的使用,但它存在图像拖影问题。本文分析了帧转移模式CCD相机图像拖影形成的原因,并提出了消除图像拖影的算法。介绍了用该算法消除图像拖影的实例,验证了方法的有效性。     

数码相机在学术论文远程校对中的应用

本文介绍了一种新的学术论文远程校对方式,即用数码相机将纸质校样转换成数码照片,之后用图片压缩软件Photo Resizer压缩数码照片并用winrar打包,以适于作为E-mail附件成功地传送给作者。与纸质校样校对PDF校样校对方式相比,该方法具有简便、快捷的优点。     

Design approach for a high-resolution microwave imaging radio camera

The angular resolution of an imaging device is the order of the reciprocal of the number of wavelengths across the aperture. To achieve the high resolution typical of optical instruments at microwaves, apertures miles in size may be required. The requirements for such a device, called a radio camera, are conformality with the terrain, a sparsely filled aperture of randomly (or nearly so) located elements, self-adaptive beam forming and a source of microwave illumination. Based on this design approach, a 1000-ft L-band radio camera is under development at the Valley Forge Research Center of the Moore School. This paper discusses the status of current development of the device.