Infrared images are firstly analyzed using the multifractal theory so that the singularity of each pixel can be extracted from the images. The multifractal spectrum is then estimated, which can reflect overall characteristic of an infrared image. Thus the edge and texture of an infrared image can be accurately extracted based on the singularity of each pixel and the multifractal spectrum. Finally the edge pixels are classified and enhanced in accordance with the sensitivity of human visual system to the edge profile of an infrared image. The experimental results obtained by this approach are compared with those obtained by other methods. It is found that the proposed approach can be used to highlight the edge area of an infrared image to make an infrared image more suitable for observation by human eyes.OCIS code: 100.0100.This work was supported by the Natural Science Foundation of Heilongjiang Province under Grant No.F200818. E-mail: ythaa@163.com1. G. Xia and B. Zhao, Chin. Opt. Lett. 5, 51 (2007).2. G. Wang, L. Xiao, Z. Jiang, Y. Song, and A. He, Acta Opt. Sin. (in Chinese) 26, 1345 (2006).3. T.-L. Ji, M. K. Sundareshan, and H. Roehrig, IEEE Trans. Med. Imaging 13, 573 (1994).4. K. A. Panetta, E. J. Wharton, and S. S. Agaian, IEEE Trans. Syst. Man Cybern. B 38, 174 (2008).5. J. Zhao, C. Yang, and B. Yu, Acta Photon. Sin. (in Chinese) 32, 61 (2003).6. K. Ferens and W. Kinsner, in IEEE WESCANEX ’95 Proceedings 438 (1995).7. I. Reljin, B. Reljin, I. Pavlovic, and I. Rakocevic, in Proceedings of 10th Mediterranean Electrotechnical Conference 2, 490 (2000).8. J. Liu, K. Bowyer, D. Goldgof, and S. Sarkar, in Proceedings of 1997 International Conference on Information, Communications and Signal Processing 170 (1997).9. B. B. Chaudhuri and N. Sarkar, IEEE Trans. Pattern Anal. Mach. Intell. 17, 72 (1995).