Watermark Extraction in DWT Domain with MATLAB Implementation and SNR Analysis

Resource Overview

MATLAB-based watermark extraction using Discrete Wavelet Transform (DWT) domain techniques with signal-to-noise ratio (SNR) performance evaluation

Detailed Documentation

This document discusses watermark extraction techniques in the Discrete Wavelet Transform (DWT) domain, MATLAB-based implementation methodologies, and signal-to-noise ratio (SNR) analysis. The implementation typically involves decomposing watermarked images using multi-level DWT through functions like wavedec2(), followed by extracting embedded watermark data from specific sub-bands (usually LH, HL, or HH). Key MATLAB functions include dwt2() for transformation and idwt2() for inverse transformation, with SNR calculations performed using mean squared error comparisons between original and extracted watermarks. The algorithm efficiently separates watermark information from host image components while maintaining visual quality through proper coefficient selection and thresholding techniques.