Focus Measure Based on the Image Moments

Focus measure plays an important role in the passive optical imaging systems. However, most of existing focus measure is prone to be affected under the noisy conditions. In this study, we proposed a novel focus measure by using the blocked image moment functions and variance statistics. We first divide the image into $8 \times 8$ non-overlapping blocks, and compute the Chebyshev moment $T_{11}$ for each image blocks, then use the statistical method to construct the focus measure. The experimental results under different noisy conditions indicate the robustness of the proposed focus measure.