Home Author Index Search Volume 1 May 2009 ISSN 1797-9617

International Journal of

Recent Trends in Engineering

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International Journal of Recent Trends in Engineering (IJRTE)

ISSN 1797-9617

Volume 1, Number 1, May 2009

Issue on Computer Science

Page(s): 318-322

Adaptive Histogram Equalization and Logarithm Transform with Rescaled Low Frequency DCT Coefficients for Illumination Normalization

Virendra P. Vishwakarma, Sujata Pandey and M. N. Gupta

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A new approach for illumination normalization that is robust under varying lighting conditions is presented in this paper. For illumination normalization discrete cosine transform (DCT) is applied on the images captured under varying lighting conditions. Most of the illumination variations as well as various facial features of a human face correspond to low frequency region. A proper down scaling of low frequency DCT coefficients is utilized in our approach of illumination normalization. The images captured under varying illumination have low contrast. For contrast stretching the adaptive histogram equalization is applied on face images. For further enhancement of the images, logarithm transform is employed. To analyze our illumination normalization method, we have used Yale Face Database B. The results show better appearance of images and have been discussed with other approaches.

Index Terms

Adaptive histogram equalization, discrete cosine transform, face recognition, illumination normalization, logarithm transform

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