Robust Focus Measure for Unsupervised Auto-Focusing Based on Optimum Discrete Cosine Transform Coefficients
- Authors
- Jeon, Jaehwan; Lee, Jinhee; Paik, Joonki
- Issue Date
- Feb-2011
- Publisher
- IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
- Keywords
- Digital auto-focusing; focus measure; discrete cosine transform; contrast detection auto-focusing; direction of image
- Citation
- IEEE TRANSACTIONS ON CONSUMER ELECTRONICS, v.57, no.1, pp 1 - 5
- Pages
- 5
- Journal Title
- IEEE TRANSACTIONS ON CONSUMER ELECTRONICS
- Volume
- 57
- Number
- 1
- Start Page
- 1
- End Page
- 5
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/21750
- DOI
- 10.1109/TCE.2011.5735472
- ISSN
- 0098-3063
- Abstract
- In this paper we present a robust focus measure for unsupervised auto-focusing based on optimum discrete cosine transform (DCT) coefficients. DCT has a low computational complexity due to real-valued coefficients, and a small number of coefficients have to be calculated to achieve a good spectral representation of an image. The focusing region of an input image is divided into non-overlapping 8 x 8 sub-images, and spectra of sub-images are obtained by 8 x 8 DCT. The focusing measure is computed from the middle frequency components. By appropriately chosen DCT coefficients, the proposed focusing measure is robust to Gaussian and impulsive noises. Experimental results show that the proposed method is more effective than the traditional methods based on the comparison with well-known autofocusing uncertainty measure (AUM)
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Collections - Graduate School of Advanced Imaging Sciences, Multimedia and Film > Department of Imaging Science and Arts > 1. Journal Articles
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