Development Of High-resolution CMOS Imaging System

CMOS sensor gets rapid development in recent years, being used more widely in relevant areas. It has got advantages not only in its traditional features, like low-power, high integration, and high yield, but also in its substantial performance improvement, which helps CMOS sensor catch up with CCD sensor. A high-resolution imaging system based on CMOS sensor is developed in this subject, to observe target in distress and its surroundings under water, which is part of the "Technology of Fast Approaching Maritime Distress Target" project. The "Technology of Fast Approaching Maritime Distress Target" project searches underwater targets in distress using acoustic and optical technologies, which is researched in this thesis.This thesis develops a high-resolution imaging system based on CMOS sensor, which has accomplished high-resolution underwater imaging, and region of interest extraction. The imaging system can be devided into two parts:the slave part and the host part. The host part is developed on computer using VC++as development platform, which provides human machine interface, controls the camera, and accomplishes image acquisition and storage. The slave part is controlled by a FPGA chip using ISE 8.2 as development platform, receives commands via RS-422 interface, provides work timing to CMOS chip and ADC, caches and uploads image data.This thesis also does some research on key technologies of imaging system, including automatic exposure and automatic gain, region of interest extraction, and high-speed data transmission. Automatic exposure and automatic gain technology helps the system get pictures with appropriate brightness. Region of interest extraction technology helps improve frame rate of imaging system. High-speed data transmission technology achieves high-speed transmission of image and commands, based on LVDS and RS-422.