Invariant Digital Image Watermarking Scheme in the Projected-Frequency Domain

Hough Transform-Based Robust Informed Watermarking Approach for Medical Images

“…In the spatial domain image watermarking is directly done on the pixels of the host image and does not require any prior transform [1,2]. In the frequency domain the host image undergoes a spectral transform before performing the watermarking [3,4], i.e., the watermark will be embedded in the image's transformed coefficients space. It is well known that the frequency methods are more robust against attacks than the spatial methods [4].…”