High resolution image fusion algorithm based on multi-focused region extraction

• A novel image fusion algorithm based on focused region extraction is proposed.
• Probability filtering is introduced to improve the robustness of focus measure.
• The method improves image registration accuracy and the fused image quality.
• The method outperforms the widely used method based on affine transformation.

An efficient way to obtain the high resolution image of a scene is using a line scan camera in the manner of macro photography. Due to the limited depth of field, only some portions of the image are focused. A common solution to this problem is utilizing the multi-focus image fusion technique, in which a series of images with different focus settings is acquired and the images are fused to an all focused one. However, it is difficult to register these high resolution images. Firstly, the magnifications of different regions of an image are different because of the depths of the scene. Secondly, the accuracy of feature detection in the region out of focus is difficult to ensure. Misregistration of the multi-focus images leads to the misjudgment of focus measures and the failure of image fusion. In this paper, we propose a novel high resolution multi-focus image fusion algorithm to solve this problem. The focused regions of each image are extracted for image registration and fusion, which improves the accuracy of image registration and the quality of image fusion. Experimental results show the proposed method is superior to the traditional methods in terms of both subjective evaluation and objective evaluation.