Digital Image Processing

Khaled A. Ramadan ¹, Emad S. Hassan ², Xu Zhu ³, Abd-Elnaby Mohammed ⁴, EL-Sayed M. El-Rabaie ⁵, Fathi E.Abd El-Samie ⁶

Affiliations
1 ERTU (Egyptian Radio & TV Union), Cairo, EG
2 Dept.of Electronics and Electrical Communications, Menoufia University, EG
3 Huazhong University of Science and Technology, Wuhan, CN
4 Department of Electronics and Electrical Communication, Menoufia University, Menouf, EG
5 Electronic and Communication Engineering Dept., Menoufia University, EG
6 Department of Electronics and Electrical Communications, Menoufia University, Menouf, EG

Abstract

In this paper, we study the performance of the Digital Video Broadcasting-Terrestrial (DVB-T) system with Continuous Phase Modulation Orthogonal Frequency Division Multiplexing(CPM-OFDM). The proposed structure combines the advantage of mitigating the Peak-to-Average Power Ratio (PAPR) problem in the Power Amplifier (PA) in addition to exploiting the channel frequency diversity and power efficiency of CPM. The proposed CPM-OFDMDVB-T system is implemented with Frequency-Domain Equalization(FDE) to avoid the complexity of the equalization. Two types of frequency domain equalizers are considered and compared for performance evaluation of the system; the Zero-Forcing (ZF)equalizer and the Minimum Mean Square Error (MMSE) equalizer.Simulation results show that the performance of the CPM-OFDMDVB-T system with multi-path fading is better than its performance with single-path fading.

Keywords

DVB-T, OFDM, CPM, ZF Equalizer, MMSE Equalizer, PAPR.

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Mohammed Y. Abbass ¹, Safey A. Abdelwahab ¹, Salah M. Diab ², Bassiony M. Salam ², El-Sayed M. El-Rabaie ², Fathi E. Abd El-Samie ², Said S. Haggag ³

Affiliations
1 Engineering Department, Nuclear Research Center, Atomic Energy Authority, EG
2 Department of Electronics and Electrical Communications, Menoufia University, Menouf, EG
3 Nuclear Research Center, Atomic Energy Authority, EG

Abstract

This paper deals with the problem of blind separation of digital images from mixtures. A method to solve this problem is blind source separation (BSS) using independent component analysis (ICA). It proposes a wavelet based ICA method using Kurtosis for blind image source separation. In this method, the observations are transformed into an adequate representation using wavelet packets decomposition and Kurtosis criterion. The simulation results of performance measures show a considerable improvement when compared to FastICA. The Peak Signal-to-Noise Ratio (PSNR), Signal-to-Noise Ratio (SNR), Root Mean Square Error (RMSE) and and Segmental Signal-to-Noise Ratio (SNRseg) are used to evaluate the quality of the separated images.

Keywords

Blind Source Separation (BSS), ICA, Kurtosis.

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Ehab H. Elshazly ¹, Mahmoud A. Ashour ¹, El-Sayed M. El-Rabaie ², Alaaeldin M. Abbas ³, Fathi E. Abd El-Samie ³, H. B. Kazemian ⁴

Affiliations
1 Department of English, NCRRT, EG
2 Department of Electronics and Electrical Communications, Faculty of Electronic Engineering, Menoufia University, Menouf, 32952, EG
3 Department of Electronics and Electrical Communications, Faculty of Electronic Engineering, Menoufia University, Menouf, 32952, EG
4 London Metropolitan University, GB

Abstract

In this work, we present a secure and robust digital image watermarking algorithm using both the Discrete Wavelet Transform (DWT) and the Fractional Fourier Transform (FrFT). The main purpose of the paper is to obtain a robust watermarking algorithm that is secure and that allows multiple watermarks to be embedded in the same cover image. We first decompose the host image into its sub-bands with the 2-D DWT. After that, we implement the 2-D FrFT on the selected sub-bands. Two random Pseudo-Noise (PN) sequences are used to modulate the selected FrFT coefficients according to the watermark pixels and inverse transforms are performed to get the watermarked image. In watermark extraction, we do not need the original image. We just need the two PN sequences used in the embedding process and the watermark size. So, a correlation coefficient is used to determine whether the extracted pixel is one or zero. The proposed algorithm shows improved security, capacity and imperceptibility. Also, robustness is still within the acceptable range under different attacks.

Keywords

Watermarking, DWT, FrFT, Security, and Robustness.

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