Edge Detection Examples

edges.py

"""
Created on Mon Apr  8 12:32:37 2019

@author: jenncross
"""

import imageio
from scipy import ndimage
import matplotlib.pyplot as plt
import numpy as np


"""SQUARE"""
im = np.zeros((128,128))
im[50:100, 50:100] = 1

plt.figure()
plt.imshow(im, cmap="gray") #
plt.show()


kern = np.array([[-1, 0, 1],[-1, 0, 1],[-1, 0, 1]])

edges = ndimage.convolve(im, kern)
plt.figure()
plt.imshow(edges, cmap="bwr") 
plt.show()

kern2 = np.array([[-1, -1,-1],[0, 0, 0],[1, 1, 1]])

edges2 = ndimage.convolve(im, kern2)
plt.figure()
plt.imshow(edges2, cmap="bwr") 
plt.show()


"""WIKIPEDIA"""
im = np.array(imageio.imread('http://upload.wikimedia.org/wikipedia/commons/d/de/Wikipedia_Logo_1.0.png'), dtype = "int64")
plt.figure()
plt.imshow(im, cmap="gray") #colors here: https://matplotlib.org/examples/color/colormaps_reference.html
plt.show()



edges = ndimage.convolve(im, kern)
plt.figure()
plt.imshow(edges, cmap="bwr") 
plt.show()



edges2 = ndimage.convolve(im, kern2)
plt.figure()
plt.imshow(edges2, cmap="bwr")
plt.show()



"""ZEBRA"""

im = np.array(imageio.imread('http://upload.wikimedia.org/wikipedia/commons/e/ed/Zebra_in_black_and_white.jpg', as_gray=True), dtype = "int64")
plt.figure()
plt.imshow(im, cmap="gray") #colors here: https://matplotlib.org/examples/color/colormaps_reference.html
plt.show()

edges = ndimage.convolve(im, kern)
plt.figure()
plt.imshow(edges, cmap="bwr") 
plt.show()

edges2 = ndimage.convolve(im, kern2)
plt.figure()
plt.imshow(edges2, cmap="bwr") 
plt.show()