Displaying images with imshow in Matplotlib - Mini Project: Build & Apply

Displaying Images with imshow

📖 Scenario: You work as a data analyst and need to visualize image data to understand it better. Visualizing images helps you see patterns and details that numbers alone can't show.

🎯 Goal: You will create a simple image using numbers and display it using matplotlib's imshow function.

📋 What You'll Learn

Create a 2D list representing a grayscale image

Set a color map configuration variable

Use imshow to display the image with the chosen color map

Show the image using plt.show()

💡 Why This Matters

🌍 Real World

Displaying images is important in fields like medical imaging, satellite data analysis, and computer vision to visually inspect data.

💼 Career

Data scientists often need to visualize image data to explore patterns and communicate findings effectively.

1

Create a 2D list representing a grayscale image

Create a variable called image_data and assign it a 2D list with these exact values: [[0, 50, 100], [150, 200, 250], [255, 125, 75]]

Matplotlib

# Create the 2D list called image_data
# Your code here

Need a hint?

Think of image_data as a small grid of pixel brightness values from 0 (black) to 255 (white).

2

Set the color map configuration

Create a variable called color_map and set it to the string 'gray' to display the image in grayscale.

Matplotlib

image_data = [[0, 50, 100], [150, 200, 250], [255, 125, 75]]
# Create the color_map variable and set it to 'gray'
# Your code here

Need a hint?

The color_map tells imshow how to color the image. 'gray' means black and white.

3

Display the image using imshow

Import matplotlib.pyplot as plt. Then use plt.imshow with image_data and cmap=color_map to display the image.

Matplotlib

image_data = [[0, 50, 100], [150, 200, 250], [255, 125, 75]]
color_map = 'gray'
# Import matplotlib.pyplot as plt
# Use plt.imshow with image_data and cmap=color_map
# Your code here

Need a hint?

Remember to import matplotlib.pyplot as plt before using imshow.

4

Show the image

Add a line to call plt.show() to display the image window.

Matplotlib

import matplotlib.pyplot as plt

image_data = [[0, 50, 100], [150, 200, 250], [255, 125, 75]]
color_map = 'gray'

plt.imshow(image_data, cmap=color_map)
# Call plt.show() to display the image
# Your code here

Need a hint?

plt.show() opens a window with the image. Without it, the image won't appear.