Triangle Auto Threshold¶

Creates a binary image from a gray image using adaptive thresholding.

triangle_auto_threshold(device, img, maxvalue, object_type, xstep=1, debug=None)

returns device, thresholded image

• Parameters:
  • device- Counter for image processing steps
  • img - grayscale img object
  • maxValue - value to apply above threshold (255 = white)
  • objecttype - 'light' or 'dark', is target image light or dark?
  • xstep - value to move along x-axis to determine the points from which to calculate distance recommended to start at 1 and change if needed)
  • debug- None, "print", or "plot". Print = save to file, Plot = print to screen. Default = None
• Context:
  • Used to help differentiate plant and background

Grayscale image (green-magenta channel)

from plantcv import plantcv as pcv

# Create binary image from a gray image based
device, thresholded= pcv.triangle_auto_threshold(device,img, 255,'light', xstep=10, debug="print")

Triangle Auto-Thresholded image (xstep=10)

from plantcv import plantcv as pcv

# Create binary image from a gray image based 
device, thresholded= pcv.triangle_auto_threshold(device,img, 255,'light', xstep=1, debug="print")

Triangle Auto-Thresholded image (xstep=1)