Improved Slant and Walsh-Hadamard transforms for audio signals using watermarking as application with comparison to DCT, DWT, FWHT, LWT and Wav-Decomposition

Abstract

Audio signals are transmitted and recorded in time (or spatial) domain, transformed to frequency domain when compressed, watermarked or encrypted. The transformation is done by using some form of transform like Discrete cosine transform(DCT), Fast Fourier transform(FFT), Discrete wavelet transform( DWT), Fast Walsh Hadamard transform(FWHT) and many others. Slant transform(SLT) was mainly produced and used for images; it was proved that Slant had better performance measurements than Walsh-Hadamard transform, although they have many common characteristics, SLT has fast and simple computations ; In this paper a modified Slant transform that has the ability to work efficiently with audio files and modified WHT were introduced. The modified and other transforms were used especially in audio watermarking as one of the most important applications on both ‘transforms and audio’. The new improvements were tested on many audio files and compared to other transformers using SNR, BER, Time and other metrics.