Smooth contours in Opencv

contour_smooth.py

import numpy
import cv2
from scipy.interpolate import splprep, splev

smoothened = []
for contour in contours:
    x,y = contour.T
    # Convert from numpy arrays to normal arrays
    x = x.tolist()[0]
    y = y.tolist()[0]
    # https://docs.scipy.org/doc/scipy-0.14.0/reference/generated/scipy.interpolate.splprep.html
    tck, u = splprep([x,y], u=None, s=1.0, per=1)
    # https://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.linspace.html
    u_new = numpy.linspace(u.min(), u.max(), 25)
    # https://docs.scipy.org/doc/scipy-0.14.0/reference/generated/scipy.interpolate.splev.html
    x_new, y_new = splev(u_new, tck, der=0)
    # Convert it back to numpy format for opencv to be able to display it
    res_array = [[[int(i[0]), int(i[1])]] for i in zip(x_new,y_new)]
    smoothened.append(numpy.asarray(res_array, dtype=numpy.int32))

# Overlay the smoothed contours on the original image
cv2.drawContours(original_img, smoothened, -1, (255,255,255), 2)

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