Olivier Egger

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Digital images have become an important source of information in the modern world of communication systems. In their raw form, digital images require a tremendous amount of memory. Many research efforts have been devoted to the problem of image compression in the last two decades. Two different compression categories must be distinguished: lossless and(More)
In this paper, the problem of progressive lossless image coding is addressed. A nonlinear decomposition for progressive lossless compression is presented. The decomposition into subbands is called rank-order polynomial decomposition (ROPD) according to the polynomial prediction models used. The decomposition method presented here is a further development(More)
We address the problem of the choice of subband filters in the context of image coding. The ringing effects that occur in subband-based compression schemes are the major unpleasant distortions. A new set of two-band filter banks suitable for image coding applications is presented. The basic properties of these filters are linear phase, perfect(More)
In this paper the problem of object coding is addressed. In order to satisfy the needs of new applications in a multi-resolution environment the problem of object{oriented coding has to be addressed. In this paper a new approach of object coding is proposed. It is based on an arbitrarily{shaped subband transform followed by a generalized embedded zerotree(More)
In order to satisfy the needs of new applications in a multimedia environment the problem of object-oriented coding has to be addressed. In this paper two main approaches are presented to tackle this problem. First, an algorithm for shape coding is presented. It, is based on a chain coding algorithm where powerful modeling techniques are used to increase(More)