A Guttate Psoriasis That Tends to Spare Three Tattoos: A Macrophage Liaison

Figure 2

Psoriasis and tattoo #1. (a) Clinical picture. (b) Retained a color channel of Lab color space: high-peak intensity areas mark psoriasis lesions and low-level intensity areas correspond to tattooed skin segments. (c) Applying h-maxima transform followed by regional maxima, the lesional skin spots (patches) were extracted and are displayed in yellow pseudocolor. (d) Equivalently, the tattoo area was extracted by applying h-minima transform, followed by regional minima and is shown in yellow pseudocolor to enhance visualization. (e) The extracted psoriasis skin lesions’ centroids (panel (C) applied to generate Voronoi diagrams (tessellation) of the tattoo area. Voronoi polygons with and without overlapping with the tattoo area (yellow border) are displayed in red and green pseudocolors, respectively.