高校新馆安装摄像监控系统应注意的细节问题

对高校图书馆新馆在设计安装摄像监控系统时,提出要注意的一些细节上的问题,从功能需求,摄像头选型、安装位置、录像保存时间等细节问题上提出诸多的注意事项,从而保证系统投入使用后能正常有效运行。     

Accuracy of a machine-vision pellet detection system

Video cameras are employed on net pen fish farms for monitoring food pellet levels near the cage bottom. Herein, the accuracy of a new machine-vision system for the identification of a feed-wastage event and its response time are reported. Research involved novel tests and definitions, video footage recorded under different stocking and environmental conditions, and numerical filters to reduce the effects of misclassifications and patchiness of the pellet wastage record on overall system accuracy. Single-frame food pellet detection accuracy was based on the difference between computer-generated and actual frame counts of pellets greater than 30 pixels in size. A pellet wastage event was defined as a median of three or more visible pellets per frame. During tests on still video frames from different feeding events, the system missed 0.1±0.1 to 1.3±0.4 pellets frame⁻¹, and miss-classified as pellets 0±0.1 to 2.3±0.5 objects frame⁻¹ (n=264). Most missed pellet images were on top of fish images. Waste matter accounted for 65% of the misclassifications, while particles associated with poor camera maintenance accounted for approximately 24%. The average response time to a pellet wastage event was 5.1 and 11.4 s for sampling rates of 2 frames s⁻¹ and 0.5 frames s⁻¹, respectively (n=20 different pellet wastage events). The longest response time (26 s) occurred when fish were amassed against the camera and/or covering pellets. Using appropriate camera lens, camera positioning and/or ‘warning’ software can address fish-interference problems.     

CCD radiation temperature measurement method for hot continuous casting billet surface

According to the present research status and existing problems of hot continuous billet surface temperature non contact measurement technology, a real time temperature measurement model, which combines two-color(R,G) and monochrome (B) of surface radiation image, is established. The surface image is collected through tricolor charge coupled device (CCD) sensor, at the same time, the temperature dynamic response range of CCD can be improved by controlling integrated time and setting different apertures. Through computer image process technology, multi-point temperature can be measured simultaneously, and 2-D temperature field distribution on continuous casting billet surface can be realized. It is be proved by theory and application that the model and method can provide a theory and technology support for realizing surface temperature field on-line measurement for continuous casting billet.     

基于3CCD摄像机的水稻农学参数估算

水稻农学参数的估算是调控水稻生长、预测水稻产量的重要基础和根据。该文以广东省农业科学研究院大丰农场水稻研究所的稻田为研究对象,根据植物反射光谱的特性,研究3CCD摄像机水稻叶面积指数、生物量、叶绿素含量、叶长、叶宽、株高、产量等农学参数的估算,结果表明:分蘖期农学参数不适于用3CCD摄像机估算;叶面积指数在分化期估算最准确;生物量、叶绿素含量、产量均在抽穗期估算较好;3CCD摄像机不适用于大面积水稻株高、剑叶长、剑叶宽等外部特征的估算。该文为CCD摄像机的水稻估产打下基础。     

基于机器视觉的水下鲆鲽鱼类质量估计

为了更好地解决水下鲆鲽类等底栖鱼的质量估计问题,本研究获取了半滑舌鳎(Cynoglossus semilaevis)在不同生长阶段的图像和质量数据,利用图像处理技术测量出鱼的面积,并将面积与质量进行数据拟合建立模型。结果表明面积与质量的相关性可达到0.9682,测试平均相对误差为6.17%。由于鱼的质量还受其他形状参数的影响,同时测量了等效椭圆长短轴比和圆形度因子,对面积、等效椭圆长短轴比和质量,面积、圆形度因子和质量分别进行三维拟合,质量估计的平均相对误差分别为5.50%、5.62%。通过验证表明,对水底鱼拍摄的图像经过水底模板校准后的处理结果,与水外面拍摄处理后的结果一致,因此在不捕捞的情况下可以实现水底活体鲆鲽类鱼的质量估计。     

A two-camera machine vision in predicting alpha-amylase activity in wheat

Sprout damage in wheat is a serious problem worldwide because damaged wheat kernels contain alpha-amylase, an enzyme that causes poor baking quality of wheat. A two-camera machine vision (MV) with a neural network was implemented to quantify alpha-amylase activity in wheat using 16 visual properties of the kernels. Kernels were separated at image level using the marker-controlled segmentation algorithm before the properties (color, texture, and shape and size) of dorsal and ventral sides of kernels were extracted. Alpha-amylase activity in wheat was assessed analytically. The neural networks were trained, validated, and tested using the visual properties as the inputs and alpha-amylase activity as the output. The trained neural network predicted alpha-amylase activity with an accuracy of 6913 U/L (rmse) and R² value of 0.72 for the wheat samples with alpha-amylase activity ranging over 178 to 28935 (U/L). Differences between visual properties of wheat samples calculated from the top and the bottom images was less than 0.5%. Light stability in time and influence of temperature on the cameras' color stability were less than 2% of the mean values. The challenges associated with the system, and recommendations to improve the system accuracy and robustness, and to decrease the system cost are presented.     

基于CCD摄像机和ArcObjects的森林火灾自动监测系统的设计研究

通过安装在监控地点的CCD摄像机,借助卫星遥感技术、图像处理技术以及网络通讯设施,结合ArcObjects组件开发方式,在探讨森林火灾自动监测系统总体框架的基础上,对系统数据库和核心模块功能进行分析设计,建立基于CCD摄像机和ArcObjects的森林火灾自动监测系统,解决了传统的以人工实地为主的监测方式,采用CCD摄像机视频监控,结合图像处理技术和人工智能技术,提高了视频监控系统的能力。     

全球监控摄像机维护与实现

全球监控摄像机已经广泛用于多种公共场所的自动录像记录视频文件,其中监控摄像机工作环境不尽相同如超常的开机时间及高温状态,直接影响监控摄像机的使用寿命,在全球监控摄像机中还附加了水平、垂直方位及自动旋转,这就要求摄像机中频解码板的功能齐全性能可靠,否则联动的云台旋转、摄像机将无法正常工作。     

Development of benthic monitoring methods using photoquadrats and scuba on heterogeneous hard‐substrata: a boulder‐slope community case study

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