  For scalable coding, a high quality of the lowpass band of a wavelet
transform is crucial when it is used as a downscaled version of the original
signal. However, blur and motion can lead to disturbing artifacts. By
incorporating feasible compensation methods directly into the wavelet
transform, the quality of the lowpass band can be improved. The displacement in
dynamic medical 3-D+t volumes from Computed Tomography is mainly given by
expansion and compression of tissue over time and can be modeled well by
mesh-based methods. We extend a 2-D mesh-based compensation method to three
dimensions to obtain a volume compensation method that can additionally
compensate deforming displacements in the third dimension. We show that a 3-D
mesh can obtain a higher quality of the lowpass band by 0.28 dB with less than
40% of the model parameters of a comparable 2-D mesh. Results from lossless
coding with JPEG 2000 3D and SPECK3D show that the compensated subbands using a
3-D mesh need about 6% less data compared to using a 2-D mesh.
