Improved Watermarking Algorithm Based on Discrete Wavelet Transform and Fibonacci Permutation

Digital image watermark is an imperceptible, robust, secure message embedded into the image, which identify one or more owner, distributor, or recipient of the image, origin or status of the data or transaction dates. Watermarking is also used for data hiding, content labeling, broadcast monitoring, and integrity control applications. Digital watermarking resembles communication systems. Watermark is the sent message. Image is the watermark channel or carrier. Image pixels and possible attacks on marked image constitute the noise. Only the authorized parties' extracts the watermark message from the marked image by using detector. Digital watermarking has three major requirements. Watermark should be robust against noise and attacks, imperceptible and has the required capacity. These three requirements conflict with each other. To illustrate, increasing the watermark strength makes the system more robust but unfortunately decreases the perceptual quality. As a second example, increasing the capacity of the watermark decreases the robustness. In this thesis, the goal was to study digital image watermarking and develop watermarking algorithm that can achieve high imperceptibility, maximum capacity, and high robustness against image manipulation at the same time. This algorithm is based on the combination of Fibonacci permutation and discrete wavelet transforms (DWT). A binary image is used as the watermark and inserted into a mid-frequency wavelet subband of the permuted image. The watermarked image is reproduced by taking the inverse DWT and the inverse permutation. In extraction process the watermark is extracted from the watermarked image directly without using the original image. The experimental results have shown that the proposed watermark is invisible to human eyes and very robust against image manipulation, such as JPEG compression, median filtering, wiener filtering, and noises

Robust Watermarking Method for Color Images using DCT Coefficients of Watermark

Digital technologies are playing a vital role in the present communication system. This paper presents a robust and secure watermarking method to protect the copyright information of multimedia objects. In the proposed method, Discrete Wavelet Transform and Discrete Cosine Transform are applied on the cover image and then Discrete Cosine Transform coefficients of watermark image are embedded into transformed cover image. The experimental result shows the performance evaluation of the proposed method by the quality metrics as PSNR for watermarked image and NC for extracted watermark image and we have compared the results with the existing transformation methods in frequency domain based on attacks

Reversible color video watermarking scheme based on hybrid of integer-to-integer wavelet transform and Arnold transform

Unauthorized redistribution and illegal copying of digital contents are serious issues which have affected numerous types of digital contents such as digital video. One of the methods, which have been suggested to support copyright protection, is to hide digital watermark within the digital video. This paper introduces a new video watermarking system which based on a combination of Arnold transform and integer wavelet transforms (IWT). IWT is employed to decompose the cover video frames whereby Arnold transform is used to scramble the watermark which is a grey scale image. Scrambling the watermark before the concealment makes the transmission more secure by disordering the information. The system performance was benchmarked against related video watermarking schemes, in which the evaluation processes consist of testing against several video operations and attacks. Consequently, the scheme has been demonstrated to be perfectly robust

Multiple Watermarking Citra Medis Menggunakan Spread Spectrum dan Secure Hash Algorithm Berbasis Wavelet dan Hash Block Chaining

ABSTRAKSI: Citra digital khususnya citra medis membutuhkan dua hal penting yaitu deteksi keaslian (tamper detection) dan penjagaan otoritas kepemilikan (ownership). Dua hal tersebut harus dapat diimplementasikan bersamaan dalam sebuah citra sehingga dapat diketahui jika sebuah citra telah mengalami kerusakan akan tetapi identitas pemilik citra masih dapat diketahui dengan baik. Untuk mengimplementasikan dua hal ini maka dibutuhkan tanda (mark yang kita sebut watermark) yang mampu medeteksi kerusakan yang terjadi dan mampu mempertahankan identitas pemilik citra. Karena perbedaan tujuan yang dimiliki, maka akan disisipkan dua jenis watermark yaitu signature watermark yang berfungsi sebagai informasi kepemilikan dan reference watermark yang berfungsi sebagai pendeteksi jika terjadi serangan terhadap citra yang bersangkutan. Teknik ini biasa disebut sebagai multiple watermarking.Signature watermark disisipkan pada bagian pingir citra dengan tujuan agar watermark yang ada robust (tahan) terhadap modifikasi dan serangan yang ada, sedangkan reference watermark disisipkan pada bagian tengah citra dengan tujuan agar watermark yang disisipkan fragile (rentan) terhadap modifikasi dan serangan yang diberikan. Penyisipan signature watermark ini menggunakan spread spectrum pada domain wavelet dimana metode ini merupakan metode non-blind watermarking. Sedangkan penyisipan reference watermark menggunakan Hash Block Chainig (HBC) dengan Secure Hash Algorithm (SHA) sebagai fungsi hash yang digunakan. Setelah disisipkan, citra berwatermark dan watermark hasil ekstraksi akan dihitung performansinya dengan menggunakan parameter Peak Signal to Noise Ratio (PSNR), Bit Error Rate (BER) dan Mean Opinion Square (MOS).Dari hasil pengujian didapatkan kesimpulan bahwa penggunaan spread spectrum pada domain wavelet mampu menghasilkan signature watermark yang tahan terhadap proses sharpening, penambahan Gaussian noise dan kompresi JPEG. Dan dari segi kerapuhan, penggunaan SHA pada HBC menghasilkan reference watermark yang rentan terhadap modifikasi citra yang diberikan khususnya proses sharpening, penambahan Gaussian noise dan kompresi JPEG.Kata Kunci : multiple watermarking, spread spectrum, wavelet, secure hash algorithm, hash block chainingABSTRACT: Digital image, especially medical image requires two important things, there are tamper detection and ownership. Two things should be implemented simultaneously in an image so that it can be seen if an image has been damaged, but the identity of the owner of the image will still be known well. To implement these, we need the mark (is called watermark) which can detect a damage and able to maintain the identity of owner image. Because of differences purpose that are owned, the inserted watermark consists of two types of watermark, there are signature watermark that serves as a proprietary information and reference watermarks that serves as a detector if there is an attack on the relevant image. This technique is commonly referred as multiple watermarking.Signature watermark is inserted in the side of the image in order for which there is robust (resistant) for modifications and attacks that exist, while the reference watermark is inserted in the center of the image in order for the inserted watermark fragile (vulnerable) with a modification and an attack that given. Signature watermark insertion uses spread spectrum in the wavelet domain and the reference watermark insertion using Hash Block Chainig (HBC) with the Secure Hash Algorithm (SHA) as the hash function used. After be inserted, the performance of the image that have a watermark and watermark which generated from the extraction process will be calculated using Peak Signal to Noise Ratio (PSNR), Bit Error Rate (BER) and Mean Opinion Square (MOS).From the test results it was concluded that the use of spread spectrum in the wavelet domain generate signature watermark is resistance to the process of sharpening, the addition of Gaussian noise and JPEG compression. In terms of fragility, the use of SHA on HBC generate the reference watermark is vulnerable to modification, particularly given the image sharpening process, the addition of Gaussian noise and JPEG compression.Keyword: multiple watermarking, spread spectrum, wavelet, secure hash algorithm, hash block chainin

Non Blind Watermarking Process using RSA Encryption Method

With the growth of technology and continuous rapid improvement in this field, the digital content took an important role in this current era of time. Online transactions keep growing in many parts of the world. As a result it becomes the prime target for hackers and intruders. Consequently security of data has become a critical issue for experts. In this paper a robust algorithm is proposed in watermarking image to secure the digital data. The proposed algorithm is based on SVDDWT with Harr Wavelet Transform (HWT) for embedding and extracting a digital watermark in an image. The experimental result shows that this technique is robust against few attacks like Gaussian, average and JPEG compression