Transmission of DWT Block-Based KLT Watermarked Images Through MC-CDMA Wireless Channel

Abstract

This paper addresses the transmission of watermarked images using two watermarking methods over Multiple Carrier Code Division Multiple Access (MC-CDMA) wireless system. Both of the two proposed watermarking methods depend on combining two adequate mathematical transforms; the discrete wavelet transform (DWT) and Karhunen---Loeve Transform (KLT). The first method named DWT-based KLT watermarking embeds watermark during performing the KLT to selected middle and high frequency bands LH, HL and HH resulted from employing 2-level DWT on the cover image that will be watermarked. The second method named DWT block-based KLT watermarking works by splitting the host image into segments and each segment is subjected to 2-level DWT. Then, the watermark is embedded to every block during applying the KLT to selected middle and high frequency bands LH, HL and HH of each block separately. The watermarked images obtained by the two above mentioned watermarking methods are transmitted over the MC-CDMA wireless system. Then, the receiver manipulates the received watermarked image to extract the watermark. Experiment tests are performed and results ensure the superiority of proposed watermarking methods over the MC-CDMA with different signal-to-noise ratios.