【作者】 严华宇；

【导师】 李方敏；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2007， 硕士

【摘要】 玻璃在生产过程中，会产生各种各样的缺陷，比如：气泡、条纹和结石。这些缺陷都是在熔制过程中发生的。对于玻璃缺陷的允许程度，取决于该制品的用途。一般来说，不允许玻璃中有大量的明显的缺陷，否则会影响玻璃的外观质量，降低玻璃的透光性，机械强度和热稳定性，造成大量的废品和次品。本文首先分析了玻璃缺陷采集处理系统的现状，比较FPGA、DSP和ASIC三种芯片作为图像采集处理系统核心芯片的优缺点，结合项目背景和需求，提出基于FPGA的图像采集处理系统的整体方案。该方案中各个外围接口的控制逻辑、芯片控制逻辑、算法处理模块均由FPGA实现。接着详细介绍了玻璃缺陷检测中图像预处理系统的设计方案，实现了具有前端视频采集、图像预处理功能的FPGA子系统。该系统采用Altera公司的FPGA芯片作为中央处理器，由图像采集模块、异步FIFO模块、图像帧存储控制模块、图像低级处理模块、通信接口模块和FPGA配置电路组成。其中图像传感器OV9121在FPGA控制下负责图像采集，两片SDRAM作为视频图像的缓存，采样控制和滤波算法在FPGA内部实现。在本文中图像采集部分包括OV9121初始化模块、采样控制模块和SDRAM控制模块。初始化模块主要是根据设计要求，设定OV9121的工作模式、图像的分辨率、帧频等参数；采样控制模块主要提供OV9121采集图像需要的控制信号；SDRAM控制模块主要负责缓存OV9121输出的图像数据，并将图像数据送FPGA滤波模块处理。本文最后对常见图像预处理算法做出分析，包括图像的滤波与边缘检测等处理方法，得出预处理中卷积算法是重复使用较多的算法，最后来对卷积算法的FPGA实现进行了详细的说明，并讨论FPGA实现卷积算法方案上的改进，使得系统的图像处理速度得到提高，从而提高整个系统的性能。更多还原

【Abstract】 All kinds of glass defect will occur during the melting production, such as airbladder, stria and concretiono. The precision of glass depends on where and how the products are used. Generally speaking, lots of obvious glass defect are not allowed which will reduce appearance quality, transparence, mechanical intensity and heat stability, and can bring plenty of wasters.Firstly, the current state of image collection and process systems were introduced, and then, the system’s merits and demerits were compared separately which based on FPGA、DSP and ASIC , considering the background and demands of the project, the whole architecture of image collection and process system were brought forward which based on FPGA. In system, control logic module of peripheral interface、chips control logic module and algorithms module are all implemented by FPGA. And then, the solution that image pre-processing system in image detection system was detailedly introduced and FPGA subsystem was implemented which had the function of image capture and image pre-processing. The system used Alters Corporation’s FPGA as the central processor. It was composed of image capture module, asynchronous FIFO module, image frame storing control module, image low-level processing module, communication module and FPGA configuration circuit. OV9121 takes charge of image collection controlled by FPGA, and the two SDRAM are image buffer storage, image collection and filter module is realized in the FPGA.The system consists of OV9121 initialization module, image collection control module, SDRAM control module. Initialization module configure OV9121’s work mode, resolution, frame frequency which based on the system acquitment; Image collection control module provide control signal that OV9121 need when collecting image, SDRAM control module major answer for image data buffer and deliver these data to filter module.At the end of this article, the familiar image preprocess algorithms are introduced, including filters and edge detection of the image, summarize that the convolution algorithms is the most important algorithms of preprocess, finally, the convolution algorithms based on FPGA were introduced detailedly, then discuss optimization of scheme that FPGA realize the convolution algorithms, which cause the image process speed a big progess,and these improve the performance of the system.更多还原