Fig. 10From: Spatio-temporal and -spectral feature maps in photoplethysmography imaging and infrared thermographyHistogram intersection as a measure of similarity. We created two simplified histograms (\(H_M\) and \(H_P\)) with 16 (\(N_\text {bins}=16\)) different pixel values to visualize (2) and the calculation of \(\eta\)Back to article page