Divisão de Observação da Terra e Geoinformática

• area: Returns the area of the given polygon, in number of pixels.
• bBoxArea: Returns the bounding box area of the given polygon, in number of pixels.
• perimeter: Returns the perimeter of the polygon, considering the amount of pixels in its border.
• fractalDimension: Returns the fractal dimension of a given polygon, which is calculated by the following equation:

Where P is the polygon perimeter and A is the area.

• perimeterAreaRatio: Calculates the ratio between the perimeter and the area of a polygon.
• compacity: Returns the compacity of a given polygon, which is calculated by the following equation:

Where P is the polygon perimeter and A is the area.

• density: The density of a polygon is calculated by the ratio between its area and its Radius (the maximum distance between the polygon centroid and all its vertices).
• length: The Length of a polygon is the height of its bounding box.
• width: The Width of a polygon is calculated by the width of its bounding box.
• contiguity: Contiguity index assesses the spatial connectedness of pixels within a polygon to provide an index of boundary configuration.
• gyrationRadius: This attribute equals the mean distance between each pixel in the polygon and the polygon centroid.
• angle: The main angle of a polygon. It is obtained by calculating the best elliptic fit, and the angle of the bigest radius of the ellipse corresponds to the polygon angle.
• ellipticFit: Finds the best ellipse which fits outside the polygon and returns the ratio between the polygon area and the ellipse area.
• squareness: This attribute fits the minimum rectangle outside the polygon and calculates the ratio between the polygon area and the area of this rectangle. The most close to 1 is this attribute, the most similar to a rectangle the polygon is.
• circleness: It is calculated by the following equation:

Where A is the polygon area and R is the maximum distance between the polygon centroid and all its vertices.