Image processing on ECG chart for ECG signal recovery

Medical imaging plays an indispensable role on medical informatics. Most of imaging processing technologies is focused on the identification of the locations of diseases on MRI, CT, PET, and SPECT images. However, only a few researches focused on one dimension signal recovery or reconstruction of electronic signals. Spatial and frequency methods were provided to process on colour or gray-level electrocardiogram charts, including threshold segmentation and 2D Fourier transform techniques. Finally, the performance was evaluated by percentage of root mean square (PRD) for calculating waveform similarity. The results show that the spatial method offered better performance than the frequency method, especially if the RGB colours in chart are kept. Based on our investigation, the linear interpolation method provided the best interpolation with less overall PRD.