Rapid microscope auto-focus method for uneven surfaces based on image fusion.

ABSTRACT

Microscopic imaging of uneven surfaces is difficult because of the limited depth of field. In this study, we developed a rapid auto-focus method for uneven surfaces based on image fusion. The Prewitt operator was used to detect the vertical edges of the images. Then, the focus position was theoretically calculated using a Gaussian function, and image fusion was applied to obtain the final in-focus image. An experiment was designed to verify the developed method. The results revealed that this method is effective for printed circuit boards.