ANALISIS MULTIPURPOSE AUDIO WATERMARKING MENGGUNAKAN VECTOR QUANTIZATION (VQ) DALAM DOMAIN DISCRETE COSINE TRANSFORM (DCT)

ABSTRAKSI: Watermarking adalah suatu teknik penyisipan data digital ke dalam suatu multimedia baik berupa suara, gambar maupun video, dimana keberadaanya tidak dirasakan oleh indera manusia. Pada umumnya hanya digunakan satu buah watermark yang disisipkan dalam suatu data multimedia sebagai tanda hak cipta atau sebagai autentikasi data. Namun dalam kondisi tertentu, baik watermark untuk tanda hak cipta maupun watermark autentikasi kedua-duanya harus disisipkan dalam suatu file multimedia, Untuk itulah dibutuhkan suatu algoritma watermarking serbaguna (multipurpose) yang dapat melakukan kedua fungsi tersebut.Dalam tugas akhir ini, telah diimplementasikan suatu multipurpose audio watermarking berdasarkan Vector Quantization (VQ) dalam domain Discrete Cosine Transform (DCT) menggunakan codeword labeling. Penggunaan watermarking ini dapat memenuhi kebutuhan akan perlindungan hak cipta dan autentikasi data pada waktu yang bersamaan untuk suatu file audio. Dalam prosesnya, disisipkan dua data watermark yaitu robust watermark sebagai tanda hak cipta dan fragile watermark sebagai autentikasi data. Robust watermark disisipkan di dalam koefisien frekuensi tengah dari tranformasi DCT. Sedangkan fragile watermark disisipkan di dalam koefisien frekuensi tinggi dari transformasi DCT. Baik robust dan fragile watermark ini nantinya akan dapat diekstrak kembali tanpa menggunakan sinyal audio yang asli.Dalam tugas akhir ini, telah dilakukan berbagai analisis, antara lain analisis imperceptibility hasil watermark, analisis ekstraksi data watermark, dan analisis file keluaran hasil watermarking baik secara objektif maupun subjektif. Hasil dari penilaian secara objektif didapatkan nilai SNR (Signal to Noise Ratio) untuk audio ter-watermark berkisar dari 26,8 s.d 31,8 dB, untuk robust watermark nilai NC (Normalized Corelation) yang didapatkan berkisar dari 0,91 s.d 0,99 sedangkan untuk fragile watermark nilai NC yang didapatkan 0,99 s.d 1. Untuk pengukuran secara subjektif nilai MOS (Mean Opinion Score) untuk audio ter-watermark antara 3,5 s.d 4,4, untuk robust watermark antara 3,3 s.d 5, sedangkan untuk fragile watermark nilai MOS yang didapat adalah 5.Kata Kunci : audio watermarking serbaguna, vector quantization, Discrete Cosine Transform, perlindungan hak cipta, autentikasi data.ABSTRACT: Watermarking is a technique of inserting digital data into a multimedia file such as voice, image or video, where its presence is not felt by human senses. In general, only one watermark is inserted in a multimedia data as a sign of copyright or as authentication data. However, in certain circumstances, both a copyright watermark and an authentication watermark must be inserted in a multimedia file. For that purpose, a multipurpose watermarking algorithm that can perform both functions is required.In this final project, a multipurpose audio watermarking based on Vector Quantization (VQ) in Discrete Cosine Transform domain (DCT) using a codeword labeling is implemented. The use of this watermarking can meet the need for copyright protection and authentication of data at the same time to an audio file. In the process, two watermarks data those are robust watermark as copyright label and fragile watermark as data authentication are inserted. Robust watermark is inserted in the middle frequency coefficients of the DCT transformation and the fragile watermark is inserted in the high frequency coefficients of the DCT transformation. Both robust and fragile watermarks can later be extracted without using the original audio signal.In this final project, some variety of analysis are applied, including analysis of imperceptibility of the watermark, the watermark data extraction analysis, and analysis of the results of watermarking output file both objectively and subjectively. The results obtained from the objective assessment are the watermarked audio obtained SNR (Signal to Noise Ratio) values ranging from 26,8 to 31,8 dB, the robust watermark obtained NC (Normalized Correlation) values ranging from 0.91 to 0.99, while for the fragile watermark NC value ranging from 0.99 to 1. From the subjective assessment, MOS (Mean Opinion Score) values for watermarked audio is 3,5 to 4,4, the robust watermark is 3.3 to 5, while for the fragile watermark MOS value obtained was 5.Keyword: multipurpose audio watermarking, vector quantization, discrete cosine transform, copyright protection, data authentication

Identification of Sparse Audio Tampering Using Distributed Source Coding and Compressive Sensing Techniques

In the past few years, a large amount of techniques have been proposed to identify whether a multimedia content has been illegally tampered or not. Nevertheless, very few efforts have been devoted to identifying which kind of attack has been carried out, especially due to the large data required for this task. We propose a novel hashing scheme which exploits the paradigms of compressive sensing and distributed source coding to generate a compact hash signature, and we apply it to the case of audio content protection. The audio content provider produces a small hash signature by computing a limited number of random projections of a perceptual, time-frequency representation of the original audio stream; the audio hash is given by the syndrome bits of an LDPC code applied to the projections. At the content user side, the hash is decoded using distributed source coding tools. If the tampering is sparsifiable or compressible in some orthonormal basis or redundant dictionary, it is possible to identify the time-frequency position of the attack, with a hash size as small as 200 bits/second; the bit saving obtained by introducing distributed source coding ranges between 20% to 70%

ICA for watermarking digital images

A domain independent ICA-based approach to watermarking is presented. This approach can be used on images, music or video to embed either a robust or fragile watermark. In the case of robust watermarking, the method shows high information rate and robustness against malicious and non-malicious attacks, while keeping a low induced distortion. The fragile watermarking scheme, on the other hand, shows high sensitivity to tampering attempts while keeping the requirement for high information rate and low distortion. The improved performance is achieved by employing a set of statistically independent sources (the independent components) as the feature space and principled statistical decoding methods. The performance of the suggested method is compared to other state of the art approaches. The paper focuses on applying the method to digitized images although the same approach can be used for other media, such as music or video

Watermarking Technique for Multimedia Documents in the Frequency Domain

In order to secure and maintain the authenticity and integrity of multimedia documents, we use digital watermarking. This discipline can be applied to images, audios, and videos. For this reason, and to be independent of the nature of the signal composing the document to be watermarked, we will propose in this chapter two watermarking techniques, one for the audio and another for the image to watermark a video containing the two components audio and image. MDCT is combined with Watson model and a motion detection algorithm in the image watermarking technique and is combined with a psychoacoustic model to elaborate the audio watermarking technique. For the two techniques, the bits of the mark will be duplicated to increase the capacity of insertion and then inserted into the least significant bit (LSB). We will use an error correction code (Hamming) on the mark for more reliability in the detection phase. To highlight our experimental results point of view robustness and imperceptibility, we will compare the proposed techniques with some other existing techniques