From: SHERPA: an image segmentation and outline feature extraction tool for diatoms and other objects
Absolute measures | |
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CDF | "Convexity Defection Factor", depicts the percentaged difference between area resp. perimeter of contour and convex hull [53] |
PCAF | The "Percent Concave Area Fraction" compares the areas of contour and convex hull [54]. |
CHMDF | For the "Convex Hull Maximum Distance Factor" each convexity defect’s maximum distance between contour and convex hull is calculated. For distances larger than pixelwidth the squares of the distances are summed up to the CHMDF [53]. |
Relative measures | |
CDF-Match | Ratio of CDF of object and template |
PCAF-Match | Ratio of PCAF of object and template |
Compactness-Match | Ratio of heuristic descriptor "compactness" between object and template shape |