Embedding of Blink Frequency in Electrooculography Signal using Difference Expansion based Reversible Watermarking Technique
This work addresses the need for secure and efficient exchange of medical information, specifically for EOG signal analysis, but it appears incremental as it applies an existing watermarking method to a new medical data type.
The authors tackled the problem of securely embedding diagnostic parameters from Electrooculography (EOG) signals by using a reversible watermarking technique based on the Difference Expansion algorithm, achieving high Signal to Noise Ratio (SNR) and low Bit Error Rate (BER) to ensure robustness.
In the past few years, like other fields, rapid expansion of digitization and globalization has influenced the medical field as well. For progress of diagnostic results most of the reputed hospitals and diagnostic centres all over the world have started exchanging medical information. In this proposed method, the calculated diagnostic parametric values of the original Electrooculography (EOG) signal are embedded as a watermark by using Difference Expansion (DE) algorithm based reversible watermarking technique. The extracted watermark provides the required parametric values at the recipient end without any post computation of the recovered EOG signal. By computing the parametric values from the recovered signal, the integrity of the extracted watermark can be validated. The time domain features of EOG signal are calculated for the generation of watermark. In the current work, various features are studied and two major features related to blink frequency are used to generate the watermark. The high Signal to Noise Ratio (SNR) and the Bit Error Rate (BER) claim the robustness of the proposed method.