"""
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Adding Chan-Vese Contours to an Image
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This example shows how to add a contour based on an A-star traversal of the image in an area between two existing contours.

This is useful as a method to produce an average path between two contours, for example the 'upper' and 'lower' boundaries of a ripple.
Since it is common for waves to have a shape that is multivalued then a normal averaging method will not effectivey capture the average shape of the two contours.
"""

################################################################################
# We can load an image into a RippleImage object using the RippleImage class and then run `add_boundary_contours` to add our limits for the  A* contour to the image.

import matplotlib.pyplot as plt

from ripplemapper.analyse import add_a_star_contours, add_boundary_contours
from ripplemapper.classes import RippleImage
from ripplemapper.data.example import example_data

ripple_img = RippleImage(example_data[1])
add_boundary_contours(ripple_img)

################################################################################
# From here we can run `add_a_star_contours` to add the A* contour that uses these two boundaries as its limits.

add_a_star_contours(ripple_img)

################################################################################
# Plotting the image and its contours

ripple_img.plot(include_contours=True)
plt.show()