Figure 3From: SHERPA: an image segmentation and outline feature extraction tool for diatoms and other objectsResults of different segmentation procedures. a) Otsu’s thresholding, b) Otsu’s thresholding combined with histogram equalization, c) robust automated threshold selector (RATS), d) adaptive thresholding, e) Canny edge detector, f) original image data. For each object (white) only the outer contours are analyzed subsequently.Back to article page