I want to apply Gaussian blur to a particular edge of polygons. The code below generates 4 white polygons in black rectangle which the left edge in green (fig below). I want to apply the Gaussian blur just to that green edge.Please note that I can't apply cv.circle or cv.rectangle since the location of green edge is changing in each polygon.
import numpy as np
import matplotlib.pyplot as plt
import cv2 as cv
pixels = 600
my_dpi = 100
num_geo=3
coord = np.array([[[-150, -200], [300, -200], [300, 0], [150, 200], [-150, 200]],
                  [[-300, -200], [200, -300], [200, -50], [200, 300], [-150, 200]],
                  [[-140, -230], [350, -260], [350, 0], [140, 200], [-180, 220]],
                  [[-180, -240], [370, -270], [370, 0], [170, 200], [-190, 230]]])
for i in range(4):
    geo = coord[i, :, :]
    fig = plt.figure(num_geo,figsize=( pixels/my_dpi,  pixels/my_dpi),facecolor='k', dpi=my_dpi)  
    plt.axes([0,0,1,1])
    rectangle = plt.Rectangle((-300, -300), 600, 600, fc='k')
    plt.gca().add_patch(rectangle)
    polygon = plt.Polygon(coord[i],color='w')
    plt.gca().add_patch(polygon)
    b=plt.plot([coord[i][0][0], coord[i][-1][0]], [coord[i][0][1], coord[i][-1][1]], color='#008000', lw=4)
    img = cv.blur(b,(5,5))
    plt.axis('off')
    plt.axis([-300,300,-300,300])
    plt.savefig('figure2/%d.png' % i, dpi=my_dpi)
    plt.close()
