Dynamic Range Expansion, Night Vision. Stabilization, Centering. Industrial and Biomedical Applications

Abstract We begin this chapter with a very powerful property of the logarithmic image processing (LIP) model, which allows for interpreting the negative elements of the gray scale as light intensifiers. The obvious consequence of this property is the ability of LIP tools (scalar multiplication and subtraction of a constant) to enhance low-light images. This is achieved by means of dynamic range expansion or histogram modification. The proposed methods are successfully generalized to color images. Moreover, we will demonstrate how to perform, at camera speed, the stabilization of images submitted to variable lighting. Four important applications are presented. An improvement of studied algorithms is realized through local lighting corrections. At the end of this chapter, some comparisons will be made with classical enhancement methods.