In this paper, a digital image watermarking technique combining Discrete Wavelet Transform (DWT) and Discrete Fractional Fourier Transform (DFRFT) has been investigated. This is a non-blind watermarking technique that exploits multi-resolution sub-band decomposition property of DWT and applies DFRFT on selected sub-bands in DWT-transformed image. The performance of this algorithm under various ...

This paper presents two architectures for 2-D discrete wavelet transform (DWT) and inverse DWT (IDWT). The first consists of transform module, RAM module and address sequencer. The transform module, which takes uniform and regular structure with local communication, offers many advantages, e.g. simple control flow, full hardware-utilization and low-power. The second architecture features parall...

Image compression is very important for efficient transmission and storage of images .Images contain large amounts of information that requires much storage space, large transmission bandwidths and long transmission times. Therefore it is advantageous to compress the image by storing only the essential information needed to reconstruct the image. Image compression is a widely addressed research...

This paper provides comparison between two image compression technique such as DCT and DWT. Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are the most commonly used transformation. DCT has high energy compaction property and requires less computational resources. On the other hand, DWT is multi-resolution transformation. PSNR and Compression ratio are one of the parameter...

An approach for three robust and semi-blind digital video watermarking algorithms has been proposed in this paper. These algorithms are based on hybrid transforms using the combination of Discrete Cosine Transform and Singular Value Decomposition (DCTSVD), Discrete Wavelet Transform and Singular Value Decomposition (DWT-SVD) and Discrete Wavelet Transform, Discrete Cosine Transform and Singular...

In this paper, a new face recognition system based on Wavelet transform (HWT) and Principal Component Analysis (PCA) is presented. The image face is preprocessed and detected. The Haar wavelet is used to form the coefficient matrix for the detected face. The image feature vector is obtained by computing PCA for the coefficient matrix of DWT. A comparison between the proposed recognition system ...

Non-stationary signal processing applications use standard non-redundant DWT (Discrete Wavelet Transform) which is very powerful tool. But it suffers from shift sensitivity, absence of phase information, and poor directionality. To remove out these limitations, many researchers developed extensions to the standard DWT such as WP (Wavelet Packet Transform), and SWT (Stationary Wavelet Transform)...

The 2-band discrete wavelet transform (DWT) provides an octave-band analysis in the frequency domain, but this might not be ‘optimal’ for a given signal. The discrete wavelet packet transform (DWPT) provides a dictionary of bases over which one can search for an optimal representation (without constraining the analysis to an octave-band one) for the signal at hand. However, it is well known tha...

In this paper, a transform based methodology is presented for compression of electrocardiogram (ECG) signal. The methodology employs different transforms such as Discrete Wavelet Transform (DWT), Fast Fourier Transform (FFT) and Discrete Cosine Transform (DCT). A comparative study of performance of different transforms for ECG signal is made in terms of Compression ratio (CR), Percent root mean...

Due to the lack of invariant property of discrete wavelet transform (DWT), the DWT based watermarking schemes are relatively vulnerable to the watermarking attacks such as geometric variations (i.e., rotation and translation etc.). To improve the reliability of the DWT based watermark detection, this paper introduces the new multiresolution based image registration method that is used to recove...