Open Access

Quality Evaluation and Nonuniform Compression of Geometrically Distorted Images Using the Quadtree Distortion Map

  • Cristina Costa1Email author,
  • Francesco G.B. De Natale1 and
  • Fabrizio Granelli1
EURASIP Journal on Advances in Signal Processing20042004:470826

https://doi.org/10.1155/S1110865704402248

Received: 1 September 2003

Published: 29 September 2004

Abstract

The paper presents an analysis of the effects of lossy compression algorithms applied to images affected by geometrical distortion. It will be shown that the encoding-decoding process results in a nonhomogeneous image degradation in the geometrically corrected image, due to the different amount of information associated to each pixel. A distortion measure named quadtree distortion map (QDM) able to quantify this aspect is proposed. Furthermore, QDM is exploited to achieve adaptive compression of geometrically distorted pictures, in order to ensure a uniform quality on the final image. Tests are performed using JPEG and JPEG2000 coding standards in order to quantitatively and qualitatively assess the performance of the proposed method.

Keywords and phrases

geometrical distortionpicture codingquality evaluation

Authors’ Affiliations

(1)
Department of Information and Communication Technology (DIT), University of Trento

Copyright

© Costa et al. 2004