A simple Canny edge detector demo using SimpleCV.

edges.py

# Make a function that does a half and half image.
def halfsies(left,right): 
    result = left
    # crop the right image to be just the right side.
    crop   = right.crop(right.width/2.0,0,right.width/2.0,right.height)
    # now paste the crop on the left image.
    result = result.blit(crop,(left.width/2,0))
    # return the results.
    return result
# Load an image from imgur.
img = Image('http://i.imgur.com/lfAeZ4n.png')
# create an edge image using the Canny edge detector
# set the first threshold to 160
output = img.edges(t1=160)
# generate the side by side image.
result = halfsies(img,output)
# show the results.
result.show()
# save the output images. 
result.save('juniperedges.png')