Iterative Ramp Sharpening for Structure/Signature-Preserving Simplification of Images

In this paper, we present a simple and heuristic ramp sharpening algorithm that achieves local contrast enhancement of vector-valued images. The proposed algorithm performs a local comparison of intensity values as well as gradient strenght and directional information derived from the gradient structure tensor so that the sharpening is applied only for pixels found on the ramps around true edges. This way, the contrast between objects and regions separated by a ramp is enhanced correspondingly, avoiding ringing artefacts. It is found that applying this technique in an iterative manner on blurred imagery produces sharpening preserving both structure and signature of the image. The final approach reaches a good compromise between complexity and effectiveness for image simplification, enhancing in an efficient manner the image details and maintaining the overall image appearance.

GRAZZINI Jacopo;  SOILLE Pierre; 

2010-11-22

IEEE Computer Society Press

JRC59063

https://publications.jrc.ec.europa.eu/repository/handle/JRC59063,   

10.1109/ICPR.2010.1120,