Perform a heuristic search for sharp angles given an object contour and user specified parameters. The acute (sharp) angles are often associated with object tip points. Outputs a python list of points that meet criteria specified in parameters.
acute_vertex(obj, window, thresh, img, device, debug=None)
returns device, list of points that meet specified criteria
- obj - A contour of the plant object (this should be output from the object_composition.py fxn)
- window - The pre and post point distances on which to calculate angle of focal point (a value of 30 worked well for a sample image) on which to calculate the angle
- thresh - Threshold to set for acuteness; keep points with an angle more acute than the threshold (a value of 15 worked well for sample image)
- sep - The number of contour points to search within for the most acute value
- img - A copy of the original image
- device - Counter for image processing steps
- debug- None, "print", or "plot". Print = save to file, Plot = print to screen. Default = None
- Used to identify tip points based upon the angle between focal pixel and reference points on contour.
Input plant contour
import plantcv as pcv device = 1 # Identify acute vertices (tip points) of an object # Results in set of point values that may indicate tip points device, list_of_acute_points = pcv.acute_vertex(obj, 30, 15, 100, device, debug='print')
Image of points selected