  A huge advantage of the wavelet transform in image and video compression is
its scalability. Wavelet-based coding of medical computed tomography (CT) data
becomes more and more popular. While much effort has been spent on encoding of
the wavelet coefficients, the extension of the transform by a compensation
method as in video coding has not gained much attention so far. We will analyze
two compensation methods for medical CT data and compare the characteristics of
the displacement compensated wavelet transform with video data. We will show
that for thorax CT data the transform coding gain can be improved by a factor
of 2 and the quality of the lowpass band can be improved by 8 dB in terms of
PSNR compared to the original transform without compensation.
