Design And Implementation Of HDMI Microscope Camera Based On Hi3559V200 Dual Operating System Architecture

Digital Microscope Systems are widely used in life science research,industrial manufacturing,medical diagnosis,education,and other fields.Microscope cameras are an important part of digital microscope systems.Microscope camera is a kind of industrial camera,which can be divided into dedicated machine vision interface camera and general interface camera.The general interface camera is cost-effective and has a wide range of applications,and has important practical research value.This paper proposed a HDMI quick-start microscope camera based on the Hi3559V200 dual operating system architecture,which has various image processing functions,powerful video image encoding and decoding functions.As a typical embedded system,microscope camera is quiet different in hardware and software compared to general computing platform.Embedded systems can be divided into symmetric embedded systems and asymmetric embedded systems.Symmetric embedded systems are aimed to balance the load among the cores and this embedded system have a wider range of applications.Asymmetric embedded systems combined the advantages of general operating systems and real-time operating systems,so asymmetric embedded systems are more suitable for fields that have requirements for real-time and need good function scalability and human-computer interaction.The microscope camera designed in this paper can work without PC.The camera outputs video stream through HDMI interface and USB interface,supports 3840×2160 30FPS video codec and 3840×2160 picture codec.It supports external SD card or U disk for extended storage Also,the camera supports a variety of image processing functions,providing a high degree of freedom for image adjustment.The camera has a graphical user interface which can be controlled through a mouse.In addition to image processing and video image encoding and decoding,the camera also provides measurement functions.Users can use various measurement tools provided by the graphical user interface to measure real-time images on screen.The microscope camera is built on the dual operating system architecture of Linux+HuaweiLiteOS.Linux is responsible for general functions such as graphical user interface and peripheral adaptation,and Huawei LiteOS is responsible for image processing and video and picture coding and decoding.The dual operating systems run on two independent cores of the Hi3559V200 dual-core processor.The system is booted by U-boot,and use interrupts and shared memory to build inter-core communication and share video stream data.The software of the dual system microscope camera is based on the middleware designed in the paper.Middleware is a logical abstraction layer between the graphical user interface and the underlying hardware driver.The software middleware is designed based on the principles of lower coupling,higher reuse and higher efficiency.The middleware is divided into six modules,COMMON,ISP,VIDEO,UVC,TEST and LITEO,which are responsible for different functional modules.This paper puts proposed a comprehensive quick-start optimization scheme for the dual-system microscope camera.By analyzing the camera startup process,the quick-start optimization scheme improved the boot speed of camera from U-boot optimization,Linux kernel optimization,program flow optimization and other overall optimization four directions.As a result,the camera firmware is cropped,startup process and the user program process are optimized,which greatly improves the speed of the camera from power-on to output preview image.This optimization scheme improved the user experience compared with other HDMI microscope cameras.At last,the microscope camera was tested and proved to be useable,easily used and robust.Also,the boot speed result proved the effectiveness of quick-start optimization scheme.Compared with the cameras without quick-start optimization scheme,the boot speed of camera proposed in this paper is much faster.Furthermore,our camera has a clear lead is boot speed compared with other HDMI microscope cameras on the market.This microscope camera has the characteristics of various functions,high coding and decoding performance,low cost,fast start-up speed and compact structure,proved that the research in this paper has a high practical value.