The canny() function is an inbuilt function in the Python Wand ImageMagick library which is used to detect edges by leveraging a multi-stage Canny algorithm.
Syntax:
canny(radius, sigma, lower_percent, upper_percent)Parameters: This function accepts two parameters as mentioned above and defined below:
- radius: This parameter stores the radius of the gaussian filter.
- sigma: This parameter stores the standard deviation of the gaussian filter.
- lower_percent: This parameter which stores the normalized lower threshold.
- upper_percent: This parameter which stores the normalized upper threshold.
Return Value: This function returns the Wand ImageMagick object.
Original Image:
Example 1:
Python3
# Import library from Image from wand.image import Image# Import the imagewith Image(filename ='../neveropen.png') as image: # Clone the image in order to process with image.clone() as canny: # Invoke canny function canny.canny(3, 2, 0.2, 0.8) # Save the image canny.save(filename ='canny1.jpg') |
Output:
Example 2:
Python3
# Import libraries from the wand from wand.image import Imagefrom wand.drawing import Drawingfrom wand.color import Colorwith Drawing() as draw: # Set Stroke color the circle to black draw.stroke_color = Color('black') # Set Width of the circle to 2 draw.stroke_width = 1 # Set the fill color to 'White (# FFFFFF)' draw.fill_color = Color('white') # Invoke Circle function with center at 50, 50 and radius 25 draw.circle((200, 200), # Center point (100, 100)) # Perimeter point # Set the font style draw.font = '../Helvetica.ttf' # Set the font size draw.font_size = 30 with Image(width = 400, height = 400, background = Color('# 45ff33')) as pic: # Set the text and its location draw.text(int(pic.width / 3), int(pic.height / 2), 'GeeksForGeeks !') # Draw the picture draw(pic) # Invoke canny function pic.canny(4, 2, 0.3, 0.7) # Save the image pic.save(filename ='canny2.jpg') |
Output:
