Fig. 4From: Spatio-temporal and -spectral feature maps in photoplethysmography imaging and infrared thermographyEnhancing small movement in the adult measurement w/o movement: a swallowing movement was made visible at the neck by the spectral flux ratios (ratio flux pos). The map for LWIR is distorted and, thus, it cannot be said whether the highlighting worked. However, the corresponding similarity map supports a highlighting (Fig. 16)Back to article page