A New DSLR Camera Autofocusing Algorithm Based on Colour Information

Autofocusing is a very important aspect in modern DSLR photography where gradient analysis based passive autofocusing is very popular due to its simplicity and efficiency trade-off. However, the existing colour information based gradient analysis techniques do not harness all the available information in an image over multiple colour domains and over multiple inter-pixel distance values considered in gradient calculation. This paper proposes three improvements to harness this additional information, resulting in a better contrast between the focus values considered when finding the maximum focus point. Testing results on sample images verify the additional efficiency in the proposed algorithm compared to existing algorithms.