A Robust Algorithm of Digital Image Watermarking Based on Discrete Wavelet Transform

In this paper, a robust algorithm of digital image watermarking based on discrete wavelet transform is introduced It uses blind watermarking technique. Digital image watermarking is one such technology that has been developed to protect digital images from illegal manipulations. In particular, digital image watermarking algorithms which are based on the discrete wavelet transform have been widely recognized to be more prevalent than others. This is due to the wavelets\u27 excellent spatial localization, frequency spread, and multi-resolution characteristics, which are similar to the theoretical models of the human visual system

ANALISIS DAN SIMULASI BLIND IMAGE WATERMARKING DENGAN METODE QUARTENARY SEGMENTAL CROPPING BERBASIS DISCRETE WAVELET TRANSFORM

ABSTRAKSI: Salah satu metode untuk mengamankan hak cipta atas data yang berbentuk multimedia adalah dengan menggunakan teknik watermarking. Watermarking adalah suatu metode penyisipan informasi kedalam multimedia baik citra, video, maupun audio, sehingga informasi yang ditumpangkan itu tidak dapat dirasakan keberadaanya oleh indera manusia. Jenis watermark yang disisipkan dapat berupa image, teks, audio, maupun video. Watermarking terdapat dua skema yaitu non-blind watermarking dan blind watermarking. Skema watermarking non-blind tidak praktis karena memerlukan kapasitas penyimpanan dan bandwidth komunikasi yang berlipat ganda untuk pendeteksian. Sedangkan skema watermarking blind dapat mendeteksi dan mengekstraksi citra watermark tanpa memerlukan citra aslinya.Salah satu basis penyisipan watermark pada citra asli adalah dengan menggunakan discrete wavelet transform. Discrete wavelet transform merupakan metode transformasi wavelet yang membagi citra menjadi subband yang memiliki frekuensi tinggi dan rendah. Discrete wavelet transform digunakan karena sangat atraktif, efisien dalam proses komputasinya dan dapat meningkatkan ketahanan terhadap watermark yang disisipi.Pada tugas akhir ini disimulasikan blind image watermarking dengan metode quartenary segmental cropping berbasis discrete wavelet transform . Pada simulasi ini disisipkan suatu informasi berupa image/gambar. Metode penyisipan citra watermark yang digunakan adalah quarternary segmental cropping, dimana image watermark dipotong terlebih dahulu menjadi empat bagian yang sama besar sebelum disisipkan ke citra aslinya. Hasil yang diperoleh pada sistem blind image watermarking ini cukup sangat baik, terbukti dari nilai PSNR yang cukup baik sebesar rata-rata 42,46 dB s.d 57,86 dB, dan nilai MOS sebesar rata-rata 4,7 s.d 4,96. Dan untuk ekstraksi image logo dari sistem blind image watermarking ini diperoleh rata-rata nilai MOS sebesar rata-rata 3 yaitu kualitas cukup, jika proses gangguan yang tidak terlalu signifikan.Kata Kunci : Blind image watermarking, discrete wavelet transform, quartenary segmental cropping.ABSTRACT: One of methods for securing copyrights of multimedia data is to use watermarking techniques. Watermarking is a method of inserting information into a multimedia such as images, video, and audio. Where the information inserted can not sensed by human senses. The type of inserted watermark can be either image, text, audio, or video. Watermarking has two scheme, there are non-blind watermarking and blind watermarking. Non-blind watermarking scheme is not practical because it requires storage capacity and doubles communications bandwidth for detection. While blind watermarking scheme can detect and extract the watermark image without requiring the original image.One of the insertion basis of the watermark on the original image is to use the discrete wavelet transform. Discrete wavelet transform is a wavelet transform method that divides the image into subband which has high and low frequencies. Discrete wavelet transform is used because it is very attractive, efficient in computation process and can increase the resistance of the inserted watermark.This final project simulates blind image watermarking with quartenary segmental cropping method based on discrete wavelet transform. In this simulation some information in the form of image are inserted. The method used for the watermark insertion is the quarternary segmental cropping, which the first cropped watermarked image into four equal parts before inserted into the original image. The results obtained in blind image watermarking system is acceptable, as evidenced from the value of PSNR is good enough for average of 42.46 dB to 57.86 dB, and the MOS value for average of 4.7 to 4.96. And for the extraction of the image logo from blind image watermarking system is obtained that the average value MOS is 3, which is quite good if the process has less disturbance.Keyword: Blind image watermarking, discrete wavelet transform, quartenary segmental cropping

Spread spectrum-based video watermarking algorithms for copyright protection

Merged with duplicate record 10026.1/2263 on 14.03.2017 by CS (TIS)Digital technologies know an unprecedented expansion in the last years. The consumer can now benefit from hardware and software which was considered state-of-the-art several years ago. The advantages offered by the digital technologies are major but the same digital technology opens the door for unlimited piracy. Copying an analogue VCR tape was certainly possible and relatively easy, in spite of various forms of protection, but due to the analogue environment, the subsequent copies had an inherent loss in quality. This was a natural way of limiting the multiple copying of a video material. With digital technology, this barrier disappears, being possible to make as many copies as desired, without any loss in quality whatsoever. Digital watermarking is one of the best available tools for fighting this threat. The aim of the present work was to develop a digital watermarking system compliant with the recommendations drawn by the EBU, for video broadcast monitoring. Since the watermark can be inserted in either spatial domain or transform domain, this aspect was investigated and led to the conclusion that wavelet transform is one of the best solutions available. Since watermarking is not an easy task, especially considering the robustness under various attacks several techniques were employed in order to increase the capacity/robustness of the system: spread-spectrum and modulation techniques to cast the watermark, powerful error correction to protect the mark, human visual models to insert a robust mark and to ensure its invisibility. The combination of these methods led to a major improvement, but yet the system wasn't robust to several important geometrical attacks. In order to achieve this last milestone, the system uses two distinct watermarks: a spatial domain reference watermark and the main watermark embedded in the wavelet domain. By using this reference watermark and techniques specific to image registration, the system is able to determine the parameters of the attack and revert it. Once the attack was reverted, the main watermark is recovered. The final result is a high capacity, blind DWr-based video watermarking system, robust to a wide range of attacks.BBC Research & Developmen