Figure 1.

(a) A WSI of a H&E-stained biopsy containing only minor, non-interfering artefacts. (b) The tissue segmentation provided by applying Otsu thresholding to the luminance of the WSI. The clear distinction between the intensities of the tissue and the rest of the WSI caused the Otsu threshold to lie between the maximum intensity of the tissue and the minimum intensity of background, allowing for a successful tissue segmentation. (c) A WSI of an H&E-stained biopsy containing orange pen marks splitting the tissue of different levels and used to identify three features of interest. (d) The tissue segmentation provided by applying Otsu thresholding to the luminance of the WSI. The pen marks interfered with the Otsu threshold calculation, resulting in a tissue segmentation that contains tissue and pen marks.