2nd International ICST Conference on Mobile Multimedia Communications

Research Article

An affine symmetric approach to natural image compression

  • @INPROCEEDINGS{10.1145/1374296.1374332,
        author={Heechan Park and Abhir Bhalerao and Graham Martin and Andy C.  Yu},
        title={An affine symmetric approach to natural image compression},
        proceedings={2nd International ICST Conference on Mobile Multimedia Communications},
        keywords={Affine transform Image coding.},
  • Heechan Park
    Abhir Bhalerao
    Graham Martin
    Andy C. Yu
    Year: 2006
    An affine symmetric approach to natural image compression
    DOI: 10.1145/1374296.1374332
Heechan Park1,*, Abhir Bhalerao1,*, Graham Martin1,*, Andy C. Yu1,*
  • 1: University of Warwick, UK
*Contact email: heechan@dcs.warwick.ac.uk, abhir@dcs.warwick.ac.uk, grm@dcs.warwick.ac.uk, andycyu@dcs.warwick.ac.uk


We approach image compression using an affine symmetric image representation that exploits rotation and scaling as well as the translational redundancy present between image blocks. It resembles fractal theory in the sense that a single prototypical block is needed to represent other similar blocks. Finding the optimal prototypes is not a trivial task particularly for a natural image. We propose an efficient technique utilizing independent component analysis that results in near-optimal prototypical blocks. A reliable affine model estimation method based on Gaussian mixture models and modified expectation maximization is presented. For completeness, a parameter entropy coding strategy is suggested that achieves as low as 0.14 bpp. This study provides an interesting approach to image compression although the reconstruction quality is slightly below that of some other methods. However the high frequency details are well-preserved at low bitrates, making the technique potentially useful in low bandwidth mobile applications.