Wavelet Transform Application in Biomedical Image Recovery and Enhancement

摘要

The paper presents selected mathematical methods of digital image enhancement applied to magnetic resonance images of the human brain. This topic forms a general interdisciplinary area of Digital Signal Processing (DSP). The work is motivated by a need to process digital images after their acquisition. This is caused by two reasons. Firstly, the digital images can be taken in low quality and secondly the quality of images is getting lower during their transmission. The goal of this work comes out from a need to enhance biomedical images. The methods described in the paper have been designed generally, i.e. it is possible to use them according to declared limitations and recommendations for both all digital images (understood as two-dimensional signals) and one-dimensional signals. The main part of the paper presents methods of the recovery of degraded parts and resolution enhancement of digital images. The wavelet transform approach has been adopted here and used for the recovery of the corrupted image regions. Proposed wavelet transform method for image resolution enhancement forms an alternative to the linear and the Fourier transform interpolation. Results of the proposed methods are presented for simulated signals and biomedical magnetic resonance images. Resulting algorithms are closely related to signal segmentation, change points detection and prediction with the use in process control, computer vision, signal or image processing and computer intelligence.