Table of Contents
What is DCT in watermarking?
DCT Transform Digital Watermarking is similar to spatial domain watermarking except, instead of altering the image bit plane pixel LSB, the frequency coefficients are alternated. DCT (discrete cosine transform) domain watermarking is robust against attacks such as noising, compression, sharpening, and filtering.
What is robust watermarking algorithm?
Robust watermarking is the watermarking algorithm that can survive not only such general operations such as compression, adding noise, filtering, A/D or D/A conversion, and so forth, but also such geometric attacks such as rotation, scaling translation, shearing, and so forth. It is often used in ownership protection.
What is watermarking algorithm?
The developed algorithm is a blind watermarking technique that meets the requirements of invisibility and robustness. Watermarking is performed by embedding a watermark in the middle-frequency coefficient block of three DWT levels. The PNN is used during watermark extraction.
What is watermarking in image processing?
Digital image watermarking is a technique in which watermark data is embedded into a multimedia product and, later, is extracted from or detected in the watermarked product. These methods ensure tamper-resistance, authentication, content verification, and integration of the image [1].
What is the difference between DCT and DFT in image processing?
Like the discrete Fourier transform (DFT), a DCT operates on a function at a finite number of discrete data points. The obvious distinction between a DCT and a DFT is that the former uses only cosine functions, while the latter uses both cosines and sines (in the form of complex exponentials).
Why DCT is preferred over DFT for image transform?
> DCT is preferred over DFT in image compression algorithms like JPEG > because DCT is a real transform which results in a single real number per > data point. In contrast, a DFT results in a complex number (real and > imaginary parts) which requires double the memory for storage.