  Images of a scene observed under a variable illumination or with a variable
optical aperture are not identical. Does a privileged representant exist? In
which mathematical context? How to obtain it? The authors answer to such
questions in the context of logarithmic models for images. After a short
presentation of the model, the paper presents two image transforms: one
performs an optimal enhancement of the dynamic range, and the other does the
same for the mean dynamic range. Experimental results are shown.

Computer Vision and Pattern Recognition