Comparison of different techniques of camera autofocusing

Abstract

Automatic focusing has become essential part of imaging system as the image quality matters. There have been many researches carried out for autofocusing. Autofocusing gives the benefit of high-contrast image capturing even while the scene or imaging system is moving. The mechanism adjusts focal point of imaging system so that it gives the high contrast image. Need of different autofocusing technique arises as a single autofocusing mechanism cannot serve all the application. Autofocusing is divided into (i) Active and (ii) Passive autofocusing. Active autofocusing is good choice for SLRs, but it cannot be used when using an independent light source is not possible. Passive autofocusing is the best solution in such cases which captures the scene and analyzes to determine focus and is fractioned into two sub categories (i) Contrast (ii) Phase. This paper concludes the different autofocusing techniques and its applications.