[IPOL announce] new preprint: Selective Contrast Adjustment by Poisson Equation

[announcements about the IPOL journal]

A new preprint is available in IPOL: http://www.ipol.im/pub/pre/41/

Selective Contrast Adjustment by Poisson Equation
by Ana-Belen Petro and Catalina Sbert

Abstract
Poisson Image Editing is a new technique permitting to modify the 
gradient vector field of an image, and then to recover an image with a 
gradient approaching this modified gradient field. This amounts to solve 
a Poisson equation, an operation which can be efficiently performed by 
FFT. This paper describes an algorithm applying this technique, with two 
different variants. The first variant enhances the contrast by 
increasing the gradient in the dark regions of the image. This method is 
well adapted to images with back light or strong shadows, and reveals 
details in the shadows. The second variant of the same Poisson technique 
enhances all small gradients in the image, thus also sometimes revealing 
details and texture.