Complex Wavelet-Based Compression
نویسنده
چکیده
This thesis gives an introduction to the discrete complex wavelet transform, followed by a mean square error based performance analysis of complex wavelet-based compression of synthetic aperture radar (SAR) data within the software framework of the JPEG 2000 Verification Model (VM). With the many varied wavelets available to the signal processing community, it can be difficult to determine which wavelet is optimally suited for a particular type of signal. Often the easiest method to determine suitability is to simply test them. This thesis compares the 9/7 Daubechies wavelet with the complex-valued symmetric Daubechies wavelets for the task of lossy compression of SAR data. This work has shown that symmetric Daubechies wavelets (SDW) can achieve better compression then the 9/7 Daubechies wavelet for SAR data when using MSE as the benchmark. The SDW are also shown to have less prounounced phase artifacts. These results have all been achieved despite the fact that the lossy compression methods in the JPEG 2000 VM were not designed with complex-valued wavelets in mind. Any future codec work will be able to exploit the newly available phase information for additional gains without having to start from a position of disadvantage.
منابع مشابه
Image Compression Method Based on QR-Wavelet Transformation
In this paper, a procedure is reported that discuss how linear algebra can be used in image compression. The basic idea is that each image can be represented as a matrix. We apply linear algebra (QR factorization and wavelet transformation algorithms) on this matrix and get a reduced matrix out such that the image corresponding to this reduced matrix requires much less storage space than th...
متن کاملImplementation of VlSI Based Image Compression Approach on Reconfigurable Computing System - A Survey
Image data require huge amounts of disk space and large bandwidths for transmission. Hence, imagecompression is necessary to reduce the amount of data required to represent a digital image. Thereforean efficient technique for image compression is highly pushed to demand. Although, lots of compressiontechniques are available, but the technique which is faster, memory efficient and simple, surely...
متن کامل2D Dual-Tree Complex Wavelet Transform Based Image Analysis
Data compression is important in storage and transmission of information. Especially digital image compression is important due to the high storage and transmission requirements. By removing the redundant data, the image can be represented in a smaller number of bits and hence can be compressed. Various compression techniques have been proposed in recent years to achieve good compression. This ...
متن کاملDual Tree Complex Wavelet Transform Based Image Compression Using Thresholding
Large size images consist of multiple bands data which occupies large space. Image compression becomes important for such large image or data’s to reduce the bandwidth in transmission over a network and in storage space. Wavelet transform is an efficient tool with some limitations for various image processing applications. And these limitations are overcome by complex wavelet transform. In this...
متن کاملECG Signal Compression Technique Based on Discrete Wavelet Transform and QRS-Complex Estimation
In this paper, an Electrocardiogram (ECG) signal is compressed based on discrete wavelet transform (DWT) and QRS-complex estimation. The ECG signal is preprocessed by normalization and mean removal. Then, an error signal is formed as the difference between the preprocessed ECG signal and the estimated QRS-complex waveform. This error signal is wavelet transformed and the resulting wavelet coeff...
متن کامل