Research On Imaging Evaluation Of CCD Camera Basing On MTF Method

With increasingly extensive application of CCD visible light imaging systems, there exists stricter demand for better reliability in evaluation of imaging quality. This paper analyses working process of CCD visible light imaging systems and basic principle of Knife-Edge method for Modulation Transfer Function. Experiments are designed to analyze the influence of SNR on MTF measurement results. Selection of Knife-Edge image is also discussed for its influence on test results.The first designed experiment achieves to measure MTF curves at different SNR with adjusting the luminance L of target to control SNR. The next focuses on only one target image. Selecting part of the image is based on the center of Knife-Edge. The experiments are under constant width or height condition for researching the influence of the other parameter on MTF curves measurement.Conclusion: This research is focused on testing the MTF of SONY A350 camera. Since SNR is higher 52.5, the obtained MTF curves become reliable. When selecting Knife-Edge image, the more closer to 1:1 the ratio of height and width is, the more fitting for evaluation reference demand the obtained MTF curves are. Compare and analyze 2 MTF curves which respectively belong to a350 and DMC-LX7 satisfying above conditions with the same SNR approximated to 20 db.