Download or read book A Digital Image Watermarking Technique on Multiple Transform Methods written by Meekyeong Kim and published by . This book was released on 2017 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Copyright protection of digital content has emerged as one of the most pressing issues in the digital content marketplace. Digital watermarking may provide an effective method for identifying the copyright ownership of digital content such as images, audio and video against unauthorized use and distribution. The basic idea of digital watermarking involves embedding or hiding the copyright and ownership information of digital content imperceptibly as a watermark within the content itself. Our study proposes the development of an efficient digital image watermarking algorithm based on a multiple transform method that combines the benefits of the frequency decomposition ability of the discrete wavelet transform (DWT) and the unpredictable random distribution property of the discrete fractional random transform (DFRNT), while using a 2D barcode to improve the algorithm's robustness, imperceptibility, security and extraction performance. As the first step in developing the proposed system, we implement our watermark generation process by adopting a two-dimensional (2D) barcode as an information hiding method and a self-designed block code pattern in order to ensure the extraction performance of watermarks. A generated 2D barcode is then converted through block code encoding and scrambling conversion, which increase the hidden computational complexity of information, thus bolstering the security of the algorithm. The 2D barcode and block code also feature a self-error-correction function that can correct the bit error in the process of extracting watermark. Next, we implement the multiple transform process by adopting the DWT-DFRNT transform method in order to ensure the robustness and security of the watermarking algorithm. A host image is used as the input signal into 2D-DWT and is decomposed into four frequency sub-bands. The generated sub-band's coefficients are used as input data into DFRNT. Using the quantization technique, we then embed the generated watermark image into the DWT-DFRNT transformed image, transforming the quantized signal through the inverse DFRNT (IDFRNT) and the inverse DWT (IDWT) sequentially. Finally, the watermarked image signal is generated as the output. Experimental results present that our proposed algorithm improves extraction performance by accurately extracting the hidden information in the 2D barcode from the detected watermark. The findings also show that combining the dual transform method, DWT and DFRNT, improves the security and robustness of the watermarking algorithm in defending against basic image signal processing and common attacks.