Nonlinear Image
Enhancement
Image enhancement is a preprocessing technique to improve
the visibility and highlight the features and details of the image for face
detection under varying lighting conditions. Three nonlinear image enhancement
algorithms - LDNE (luma-dependent nonlinear enhancement), INDANE (integrated
neighborhood dependent algorithm for nonlinear enhancement) and AINDANE
(adaptive INDANE, which was implemented based on the images statistic feature,
such as histogram distribution, standard deviation, and frequency domain
information.) - based on the principle of sensory attributes of the human visual
cortex, are being developed in the Vision & VLSI Systems Laboratory. It is
observed that LDNE, INDANE and AINDANE algorithms provide extremely optimal
results for preprocessing images so that the face regions in an image captured
under extremely low or non-uniform lighting conditions are brightened and made
more distinct.
Move mouse over images to see enhancement
