An adaptive image enhancement method based on logarithmic image processing is presented. 
Using of combination of logarithmic multiplicative 
operators allows to enhance low contrast image fragments. 
New algebraic structure, which presents generalized basic model 
for logarithmic image processing, is used. 
In this structure interval (-M, M) is a set of pixel gray levels. 
Operations of addition and multiplication by real scalar are defined for this interval. 
The set of gray levels with these operations creates real vector space. 
New structure generalizes also known models of Jourlin-Pinoli 
and Patrascu over the use of parametric representation. 
Experimental results confirm effectiveness of generalized logarithmic 
image processing model and allow to select adaptive parameter of the method.