Evert-Jan D. Pol

Medical image matching-a review with classification

A classification scheme for multimodal image matching is considered. The scope of the classification is restricted to methods that register data after acquisitions. The classification scheme may be used for any modality; not only for (2-D) projection images and (3-D) tomographic images, but also for other signal modalities that provide spatial insight into function or anatomy, e.g., EEG (electroencephalography) or MEG (magnetoencephalography) and for the real physical patient. The available literature on image matching is discussed and classified.<<ETX>>

A heterogeneous multiprocessor architecture for flexible media processing

Eclipse is a scalable architecture template for designing data-dependent stream-processing subsystems of media-processing SoCs. It combines application configuration flexibility with the efficiency of function-specific coprocessors that concurrently execute the tasks of one or more applications.

Grey value correlation techniques used for automatic matching of CT and MR brain and spine images

Grey value correlation is generally considered not to be applicable to matching of images of different modalities. In this paper we will demonstrate that, with a simple preprocessing step for the Computed Tomography (CT) images, grey value correlation can be used for matching of Magnetic Resonance Imaging (MRI) with CT images. Two simple schemes are presented for automated 3D matching of MRI and CT neuroradiological images. Both schemes involve grey value correlation of the images in order to determine the matching transformation. In both schemes the preprocessing consists of a simple intensity mapping of the original CT image only. It will be shown that the results are insensitive to considerable changes in the parameters that determine the intensity mapping. Whichever preprocessing step is chosen, the correlation method is robust and accurate. Results, compared with a skin marker-based matching technique, are shown for brain images. Additionally, results are shown for an entirely new application: matching of the cervical spine.

Image fusion using geometrical features

This paper describes a new approach to register images obtained from different modalities. Differential operators in scale space are used to extract geometric features from the images corresponding to similar structures. The resulting feature images may be matched by minimizing some function of the distances between the features in the respective images. Our first application concerns matching of brain images. We discuss a differential operator that produces ridge-like feature images from which the center curve of the cranium is easily extracted in CT and MRI. Results of the performance of these operators in 2-D matching tasks are presented. In addition, the potential of this approach for multimodality matching of 3-D medical images is illustrated by the striking similarity of the ridge images extracted from CT and MR images by the 3-D version of the operator.

TriMedia CPU64 application development environment

The architecture of the TriMedia CPU64 is based on the TM1000 DSPCPU. The original VLIW architecture has been extended with the concepts of vector processing and superoperations. The new vector operations and superoperations need to be supported by the compiler and simulator to make them accessible to application programmers. It was our intention to support these new features while remaining compliant with the ANSI C standard. This paper describes the mechanisms which were implemented to achieve this goal. Furthermore, the optimization of applications needs to address the vectorization of the functions to be implemented. Some general guidelines for producing efficient vectorized code are given.

Initial values for online response time calculations

Many real-time systems needing an online schedulability test requires exact schedulability analysis. In this paper we evaluate standard initial values for the iterative procedure to calculate worst-case response times of periodic tasks under fixed priority preemptive scheduling and arbitrary phasing. For discrete scheduling, we show that the number of iterations needed to determine the worst-case response time of a task using standard initial values increases logarithmically for an increasing worst-case computation time of that task. We present a new initial value, and prove that the number of iterations for that value is bounded. The costs of using the standard and new initial values are compared by means of an experiment. We briefly discuss the applicability of the initial value in other contexts, such as best-case response time analysis and jitter analysis.

PRMDL: a machine description language for clustered VLIW architectures

Summary form only given. PRMDL is a format of the central machine description file that contains parameters of the whole retargetable compiler-simulator framework. The format features separate software and hardware views on the processor and defines a wide scope of the framework retargetability, enabling platform-based processor design and vast design space exploration for clustered VLIW architectures.