Shape from focus

1 August 1994

journal article
Published by Institute of Electrical and Electronics Engineers (IEEE)

Vol. 16 (8) , 824-831
https://doi.org/10.1109/34.308479

Abstract

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.<>

Keywords

This publication has 7 references indexed in Scilit:

Pyramid based depth from focus
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2003
Robust focus ranging
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2003
A matrix based method for determining depth from focus
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2002
Focusing
International Journal of Computer Vision, 1988
How the Human Eye Focuses
Scientific American, 1988
A New Sense for Depth of Field
Published by Institute of Electrical and Electronics Engineers (IEEE) ,1987
Depth from focus
Pattern Recognition Letters, 1987