Issue No. 08 - August (1994 vol. 16)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/34.308479
<p>The shape from focus method presented here uses different focus levels to obtain a sequence of object images. The sum-modified-Laplacian (SML) operator is developed to provide local measures of the quality of image focus. The operator is applied to the image sequence to determine a set of focus measures at each image point. A depth estimation algorithm interpolates a small number of focus measure values to obtain accurate depth estimates. A fully automated shape from focus system has been implemented using an optical microscope and tested on a variety of industrial samples. Experimental results are presented that demonstrate the accuracy and robustness of the proposed method. These results suggest shape from focus to be an effective approach for a variety of challenging visual inspection tasks.</p>
image sequences; image texture; shape from focus method; sum-modified-Laplacian operator; image focus quality; depth estimation algorithm; optical microscope; accuracy; robustness; visual inspection tasks
Y. Nakagawa and S. Nayar, "Shape from Focus," in IEEE Transactions on Pattern Analysis & Machine Intelligence, vol. 16, no. , pp. 824-831, 1994.