Image registration is widely used in different areas nowadays. Usually, the efficiency, accuracy, and robustness in
the registration process are concerned in applications. This thesis studies these issues by presenting
an efficient intensity-based mono-modality rigid 2D-3D image registration method and constructing a novel mathematical
model for intensity-based multi-modality rigid image registration.
For mono-modality image registration,
an algorithm is developed using RapidMind Multi-core Development Platform (RapidMind) to exploit the highly
parallel multi-core architecture of graphics processing units (GPUs). A parallel ray casting algorithm is used
to generate the digitally reconstructed radiographs (DRRs) to efficiently reduce the complexity
of DRR construction. The optimization problem in the registration process is solved by the Gauss-Newton method.
To fully exploit the multi-core parallelism, almost the entire registration process is implemented in parallel
by RapidMind on GPUs. The implementation of the major computation steps is discussed. Numerical results
are presented to demonstrate the efficiency of the new method.
For multi-modality image registration,
a new model for computing mutual information functions is devised in order to remove the artifacts in the functions
and in turn smooth the functions so that optimization methods can converge to the optimal solutions accurately and efficiently.
With the motivation originating from the objective to harmonize the discrepancy between
the image presentation and the mutual information definition in previous models,
the new model computes the mutual information function using both the continuous image function
representation and the mutual information definition
for continuous random variables. Its implementation and complexity are discussed and compared with other models.
The mutual information computed using the new model appears quite smooth compared with the functions computed by others.
Numerical experiments demonstrate the accuracy and efficiency of optimization methods
in the case that the new model is used. Furthermore, the robustness of the new model is also verified.
| Identifer | oai:union.ndltd.org:WATERLOO/oai:uwspace.uwaterloo.ca:10012/4077 |
| Date | January 2008 |
| Creators | Xu, Lin |
| Source Sets | University of Waterloo Electronic Theses Repository |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
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