Plot a Point or a Line on an Image with Matplotlib
Last Updated :
17 Dec, 2020
Improve
Prerequisites: Matplotlib
Matplotlib and its constituents support a lot of functionality. One such functionality is that we can draw a line or a point on an image using Matplotlib in python.
Approach
- Import modules
- Read the image
- Plot the line or point on the image
- Display the plot/image.
Image Used:
Implementation using the above approach on the given image is provided below:
Example 1 : Drawing a point on the image.
Attribute used: marker
It is used to define what marker type should the point be displayed in.
from matplotlib import image
from matplotlib import pyplot as plt
# to read the image stored in the working directory
data = image.imread('sunset-1404452-640x480.jpg')
# to draw a point on co-ordinate (200,300)
plt.plot(200, 350, marker='v', color="white")
plt.imshow(data)
plt.show()
Output:
Example 2 : Draw a line on the image
To draw a line we will give the co-ordinates of two points in the plot function.
Attribute used: linewidth
Used to specify the width of the line.
from matplotlib import image
from matplotlib import pyplot as plt
# to read the image stored in the working directory
data = image.imread('sunset-1404452-640x480.jpg')
# to draw a line from (200,300) to (500,100)
x = [200, 500]
y = [300, 100]
plt.plot(x, y, color="white", linewidth=3)
plt.imshow(data)
plt.show()
Output:
Example 3 : Draw two intersecting lines crossing each other to make X.
from matplotlib import image
from matplotlib import pyplot as plt
# to read the image stored in the working directory
data = image.imread('sunset-1404452-640x480.jpg')
# to draw first line from (100,400) to (500,100)
# to draw second line from (150,100) to (450,400)
x1 = [100, 500]
y1 = [400, 100]
x2 = [150, 450]
y2 = [100, 400]
plt.plot(x1, y1, x2, y2, color="white", linewidth=3)
plt.axis('off')
plt.imshow(data)
plt.show()
Output :
