Grayscale Watermark Embedding Algorithm Using Wavelet Transform

This document presents a grayscale watermark embedding algorithm based on wavelet transform. The primary objective of this algorithm is to embed a grayscale watermark image into another host grayscale image. By utilizing wavelet transform decomposition - typically implemented through functions like wavedec2() in MATLAB for 2D signals - the algorithm achieves enhanced concealment of the watermark within the host image. The implementation generally involves decomposing both images into multiple frequency subbands (LL, LH, HL, HH) using discrete wavelet transform, then selectively modifying the host image's coefficients in specific subbands to embed watermark information. This wavelet-based approach offers widespread applications in digital image copyright protection, effectively preventing piracy and unauthorized duplication. Our research demonstrates that this wavelet transform-based grayscale watermark embedding algorithm shows significant potential for image copyright protection and can be adapted to various domains and industries.