ContourFilter

Contour filters are used to identify contours (solid shapes) in an image and decide which ones may look like a target and which are just noise.

Built-in filter types

• StandardContourFilter: This is the recommended contour filter for most applications as it is the simplest.
• ConvexHullContourFilter: The convex hull contour filter takes into consideration the perimeter, solidity, vertexes, area, and dimensions of contours.

Creating a StandardContourFilter object

• area: The percent of the total area the target takes up. This helps filter out contours which are too small (noise) or too large (other objects).
• fullness: The percent of the contour's area to the bounding box of its area. Values closer to 0 are contours which are not rectangular (such as 2016's vision target).
• aspectRatio: The aspect ratio of the contours width / height. Giving a decent margin of error avoids having an actual target filtered out.

ContourFilter contourFilter = new StandardContourFilter(area, fullness, aspectRatio);