| Author: | Chan, Hei-ping |
| Title: | Multiscale tomographic reconstruction by wavelet transform |
| Degree: | M.Sc. |
| Year: | 1996 |
| Subject: | Wavelets (Mathematics) Tomography Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies |
| Pages: | v, 88 leaves : ill. ; 30 cm |
| Language: | English |
| Abstract: | The filtered back-projection is the most commonly used method for reconstructing image from tomographic projection, however, the reconstructed image is not acceptable if the projection data is noisy. In this project, the problem of reconstructing an image from tomographic projection will be approached by using the wavelet based multiresolution method. By employing this method, we can construct an image depend on how fine the image detail we are interested. The first part of the work is to combine the conventional filtered back-projection (FBP) reconstruction method and the standard discretization technique to form a discrete version of the FBP reconstruction method. Based on the multiresolution analysis, an 1-D wavelet transform based multiscale decomposition is then applied, and a multiscale FBP algorithm is formed. From this algorithm, a series of multiscale approximated and detail images are generated. These reconstructed images are then examined. After that, we investigate how a gaussian white noise corrupts the quality of the reconstructed image by employing a multiresolution approach. Finally, a denoising technique based on the wavelet transform domain filtering and cycle spinning is developed, which is applied to filter the white noise in the reconstructed images. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b12306915.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.78 MB | Adobe PDF | View/Open |
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