# Difference between revisions of "Shape Filter"

Shape Filter Plugin (ImageJ/Fiji)
Author Thorsten Wagner
Maintainer Thorsten Wagner (wagner@biomedical-imaging.de)
File shape_filter_x.y.z.jar [1]
Source Github [2]
Development status active

## General Description

The ImageJ Shape Filter Plugin uses the [ij-blob] library to characterize and filter objects in binary scenes by its shape. Therefore, several features are calculated as shown below.

# Shape Features

• Area ($A$): The area enclosed by the outer contour of an object.
• Area Convex Hull ($C$): The area enclosed by the convex hull of the outer contour of an object.
• Perimeter ($P$): The perimeter of the outer contour of an object.
• Perimeter Convex Hull ($H$): The perimeter of the convex hull of the particle.
• Feret Diameter: The maximum distance between the two parallel tangents touching the particle outline in all directions.
• Min. Feret Diameter: the minimum distance between the two parallel tangents touching the particle outline in all directions.
• Long Side Minimum Bounding Rectangle: The larger side of the minimum bounding rectangle.
• Short Side Minimum Bounding Rectangle: The smaller side of the minimum bounding rectangle.
• Aspect Ratio: Defined as $L/S$
• Area to Perimeter Ratio: Defined as $A/P$
• Circularity: Defined as $P^{2}/A$
• Elongation: Defined as $1 - S/L$
• Convexity: Defined as $H/P$
• Solidity: Defined as $A/C$
• Number of Holes: The number of holes inside an object.
• Thinnes Ratio: Inverse proportional to the circularity. Furthermore it normed. It is defined as $4\pi A/P^{2}$
• Contour Temperatur: It has a strong relationship to the fractal dimension, defined as $\left(log_{2}\left(\frac{2P}{P-H}\right)\right)^{-1}$
• Fractal Box Dimension: Estimated fractal dimension by the box count algorithm. The default box-sizes are “2,3,4,6,8,12,16,32,64”.