Fig. 1. a) Multi-colour tattoo on healthy skin, normal photograph; b) the same multi-colour tattoo as a photograph through a laser-doppler device, circles indicate exemplary regions of interest within the tattoo (1 = healthy skin without tattoo, 2 = yellow pigment, 3-5 = pink pigment); c) grayscale image of the area; d) laser speckle contrast image of the tattoo; e-f) table and graph with corresponding perfusion units per region of interest (ROI) as indicated above.