Use of the Walsh Transform for scintigram enhancement
- eds.
The Discrete Walsh Transform (DWT) can be used to reduce the computation time requirements of discrete circular real convolution in the processing of radionuclide images. The standard implementation of discrete convolution uses a forward Fast Fourier Transform (FFT), application of a transfer function (filter) in the Fourier or frequency domain, and an inverse FFT. An alternate approach has been proposed which uses a forward DWT, a linear transformation in the Walsh or sequency domain, and an inverse DWT. This paper is particularly concerned with the computational advantages of the latter approach for the implementation of two-dimensional discrete circular convolution. Utilizing the patterned sparsity and symmetry of the silter matrices, the siltering procedure yields a very good approximation of the desired convolution result while requiring significantly fewer multiplications than the standard implementation of convolution using the FFT or convolution speedup algorithms. (auth)
- Research Organization:
- Franklin MeLean Memorial Research Inst., Chicago; Massachusetts Inst. of Tech., Cambridge (USA)
- NSA Number:
- NSA-33-009661
- OSTI ID:
- 4128887
- Report Number(s):
- CONF-730687--
- Country of Publication:
- United States
- Language:
- English
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