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Vol: 47(61) No: 2 / June 2002 Image Enhancement Using The Mean Dynamic Range Maximization With Logarithmic Operations Vasile Patrascu Department of Informatics Technology, TAROM Company, Bucureşti-Otopeni, Romania, e-mail: vpatrascu@tarom.ro Keywords: Image enhancement, logarithmic image processing, mean dynamic range. Abstract In this paper we use a logarithmic model for gray level image enhancement. We begin with a short presentation of the model and then, we propose a new formula for the mean dynamic range. After that we present two image transforms: one performs an optimal enhancement of the mean dynamic range using the logarithmic addition, and the other does the same for positive and negative values using the logarithmic scalar multiplication. We present the comparison of the results obtained by dynamic ranges optimization with the results obtained using classical image enhancement methods like gamma correction and histogram equalization. References [1] K.R. Castleman, Digital Image Processing, Prentice Hall, Englewood Cliffs NJ 1996. [2] R.C. Gonzales, P. Wintz, Digital Image Processing, 2nd Edition, Addison-Wesley, New York, 1987. [3] A.K. Jain, Fundamentals of Digital Image Processing, Prentice Hall Intl., Englewood Cliffs NJ , 1989. [4] M. Jourlin, J.C. Pinoli, ”A model for logarithmic image processing”, Publication nr. 3 , Departement de Mathematiques, Univ. de Saint-Etienne 1985. [5] M. Jourlin, J.C. Pinoli, “Image dynamic range enhancement and stabilization in the context of the logarithmic image processing model”, Signal processing (41), 1995. [6] A.V. Oppenheim, R.W. Schafer, Digital Signal Processing, Prentice-Hall, Englewood Cliffs, NJ, 1975. [7] V. Patrascu, “The means of k-order for a real random variable”, In Proc. of the 28th International Workshop of the Military Technical Academy, Bucureşti, România, pp 174-177, 21-22 Oct. 1999. [8] V. Patrascu, V. Buzuloiu, “A Mathematical Model for Logarithmic Image Processing”, The 5th World Multi-Conference on Systemics, Cybernetics and Informatics, Vol 13, SCI2001, Orlando, USA, pp. 117-122 July 22-25, 2001. [9] V. Patrascu, V. Buzuloiu, “Color Image Enhancement in the Framework of Logarithmic Models”, The 8th IEEE International Conference on Telecommunications, Vol. 1, ICT2001, Bucharest, Romania, pp. 199-204, June 4 - 7, 2001. [10] V. Patrascu, I. Voicu, “An algebraical model for gray level images”, In Proc. of the 7th International Conference, Exhibition on Optimisation of Electrical and Electronic Equipement, OPTIM 2000, Braşov, România, pp. 809-812, 11-12 May 2000. [11] V. Patrascu, “A mathematical model for logarithmic image processing”, PhD thesis, “Politehnica” University of Bucharest, May 2001. [12] T.G. Stockham, “Image processing in the context of visual model”, Proc. IEEE, Vol. 60, July 1972. |