Background Subtraction¶

Creates a binary image from a background subtraction of the foreground using cv2.BackgroundSubtractorMOG().
The binary image returned is a mask that should contain mostly foreground pixels.
The background image should be the same background as the foreground image except not containing the object of interest.

Images must be of the same size and type.
If not, larger image will be taken and downsampled to smaller image size.
If they are of different types, an error will occur.

plantcv.background_subtraction(foreground_image, background_image)

returns foreground mask

• Parameters
  • foreground_image - grayscale or RGB image object
  • background_image - grayscale or RGB image object
• Context:
  • Used to extract object from foreground image containing it and background image without it.
  • E.g. A picture of a pot and the background and a picture of the plant, pot, and same background. Preferably taken from same background.
• Example use:
  • See below.

Foreground Image

Background Image

from plantcv import plantcv as pcv

# Set global debug behavior to None (default), "print" (to file), or "plot" (Jupyter Notebooks or X11)

pcv.params.debug = "print"

# Create a foreground mask from both images using cv2.BackgroundSubtractorMOG().
fgmask = pcv.background_subtraction(foreground_image, background_image)

Foreground Mask