ANALYSIS OF DIGITAL WATERMARKING SCHEMES FOR SECURING DIGITAL MEDIA

With the proliferation of digitized media, the need of digital watermarks as a copyright protection, ownership identification and a secure way of embedding information has become important. A useful watermark technique should be robust against malicious at tacks or tampering to remove the watermark and should not greatly affect the quality of the original file. Every watermarking system has two main parts: watermark embedding and watermark extraction/decoction. In conventional cryptographic systems, once the information is decrypted, the recipient can misuse it. The reproduction and retransmission cannot be tracked easily. In this dissertation thesis, selected major watermarking techniques are investigated for digital image as well as audio files. The selecti on was carried out after intensive study and feasibility checking of latest available techniques. The robustness and effectiveness of these watermarking techniques are tested both quantitatively and qualitatively. The results obtained after experimental st udy of watermarking of, digital image for LSB technique in image - image, image - text and circular watermarking technique, digital audio for Echo hiding, amplitude modulation, and high frequency modulation are more than satisfactory. The watermark has been em bedded and extracted successfully without affecting the quality of original file in noticeable extent.