抄録
This paper proposes a novel scheme for image focusing by introducing a new focus measure based on self-matching methods. A unique pencil-shaped profile is identified by comparing the similarity between all patterns extracted around the same position in each scene. Based on this profile, a new criterion function called Complementary Pencil Volume (CPV) is defined to evaluate focus or defocus scenes based on similarity rate of self-matching, which visually represents the volume of a pencil-shape profile. Among matching methods, Orientation Code Matching (OCM) is recommended due to its invariant with regards to illuminations and contrasts. Several experiments using a Telecentric lens are implemented to demonstrate the efficiency of proposed measures. Outstandingly, comparing conventional focus measures, shows that the proposed method, focus measure based on OCM is robust against changes of brightness or illumination. Using this method, pan-focused images are composed and depth informations are represented by comparing the focus and defocus region in the scenes both under low and high illumination conditions.
