High Definition Bayer Image Real-Time Acquisition System

The people have focused requirements on the image quality with the improvement of human live, which put forward higher requirements to the image acquisition system in real-time bandwidth and real-time. In particular, the high definition bayer image that has a rich color space with 12 bit,16 bit or more directly obtained from the sensor are raw data. As it directly outputs, the data quantity of bayer image is very large. Therefore, requirements of the performance of the image acquisition system are harsher. Now bayer format data is obtained only from the high-end cameras, however they are very expensive. So the development of the higher performance price ratio bayer image acquisition system has the great market and application space.Based on the guideline of lower price and higher performance, the high definition bayer image acquisition system is designed based on the scheme of CMOS sensor, USB2.0 microcontroller chip and PC. A miron TM9M033 120Mp image sensor acquires image and CYPRESS's a smart USB2.0 CY7C68013A is used to control and transmit the image data. PC masters the image acquisition by application program. The acquired image data are transmitted to PC by the USB2.0 channel and final the image is processed.The design is divided tow parts:hardware and software. Hardware design includes image acquisition module, data transmission control module and power module. The PCB design are completed based on the signal integrity analysis, and HyporLgnx software used analyze the reflection, crosstalk, power supply's ground bounce of the critical network for the system signal characteristics. Then the methods of transmission line impedance match, increasing the line spacing and configuring appropriate filter capacitor are adopted to reduce interference. At last, the hard system design is completed. Software design is comprised of image sensor setup program, USB firmware program, USB device driver and PC application program. CY7C68013A communicates the image sensor with I2C interface to setup its register set, in accordance with the requirements of the system setting image register set so that it is operating in the linear model and completes the appropriate exposure setting. With the help of UVision2 development environment of the keil company, USB firmware program is completed. Because USB device driver development is very difficult, CYPRESS GDP is improved to fit into the system.Finally, the whole system is tested after it successfully enumerated and firmware program is right tested. Data transfer rate of the image acquisition system tested by BUS HOUDN software is up to 15MB/S. Therefore, the system can fully acquire the high-speed image data and also is applied to video surveillance and has a vide range of practical value.