Adding an image to the background of a plot increases its visual appeal and can provide contextual information or branding. Seaborn, combined with Matplotlib, offers several techniques to achieve this effect seamlessly.

In this article, we will explore the approach to add an image to the background of a plot with Seaborn.

Techniques to Add an Image Background

Below are the techniques to add an image to the background of a plot with Seaborn.

Method 1: Using ‘imshow' to Add Background Image

In this approach, we use Matplotlib‘s imshow() to display an image in the background of a Seaborn plot. The imshow() method places the image on the axes, and we adjust the plot limits to fit the background image.

Syntax:

ax.imshow(bg_image, extent=[0, 1, 0, 1], aspect='auto')

• bg_image: The image array to be displayed, loaded using plt.imread.
• extent=[0, 1, 0, 1]: Specifies the bounding box in data coordinates that the image will fill, setting the image to span from 0 to 1 on both x and y axes.
• aspect='auto': Controls the aspect ratio of the image. ‘auto’ ensures that the image’s aspect ratio adjusts automatically to fit the specified extent.

Example:

import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np

tips = sns.load_dataset('tips')

# Load background image
bg_image = plt.imread('/content/gfglogo.png')

# Create figure and axes
fig, ax = plt.subplots()

# Display the background image
ax.imshow(bg_image, extent=[0, 1, 0, 1], aspect='auto')

# Plot data
sns.scatterplot(data=tips, x='total_bill', y='tip', ax=ax)

# Adjust the plot limits to fit the background image
ax.set_xlim(0, 1)
ax.set_ylim(0, 1)

plt.show()

Output:

Method 2: Using ‘set_zorder’ to Place Image Behind Plot

In this approach, we use the set_zorder() method to place an image behind a plot in Matplotlib. First, we load the background image using plt.imread(). Then, we create a figure and axes using plt.subplots() and plot the data using sns.scatterplot. Finally, we display the background image using ax.imshow with extent=ax.get_xlim() + ax.get_ylim() to match the plot’s dimensions and set zorder=-1 to place the image behind the plot elements.

Syntax:

ax.imshow(bg_image, extent=ax.get_xlim() + ax.get_ylim(), aspect='auto', zorder=-1)

• bg_image: The image array to be displayed, loaded using plt.imread.
• extent=ax.get_xlim() + ax.get_ylim(): Sets the bounding box in data coordinates that the image will fill, combining the current x-axis and y-axis limits.
• aspect='auto': Controls the aspect ratio of the image.
• zorder=-1: Sets the drawing order for the image, ensuring it is drawn behind other plot elements.

Example:

import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np

tips = sns.load_dataset('tips')

# Load background image
bg_image = plt.imread('/content/gfglogo.png')

# Create figure and axes
fig, ax = plt.subplots()

# Plot data
sns.scatterplot(data=tips, x='total_bill', y='tip', ax=ax)

# Display the background image
ax.imshow(bg_image, extent=ax.get_xlim() + ax.get_ylim(), aspect='auto', zorder=-1)

plt.show()

Output:

Method 3: Using ‘figimage’ to Place Image on Figure Background

In this approach, we are using the figimage() method to place an image on the figure background in Matplotlib. The image is loaded with plt.imread and displayed on the figure using fig.figimage, with options to resize the image and set its transparency.

Syntax:

fig.figimage(bg_image, resize=True, alpha=0.5)

• fig.figimage: Places a raster image (array) directly into the figure.
• bg_image: The image array to be displayed, typically loaded using plt.imread.
• resize=True: Resizes the image to fit within the figure dimensions.
• alpha=0.5: Sets the transparency level of the image.

Example:

import matplotlib.pyplot as plt
import seaborn as sns

tips = sns.load_dataset('tips')

# Create figure and axes
fig, ax = plt.subplots()

# Plot data
sns.scatterplot(data=tips, x='total_bill', y='tip', ax=ax)

# Load and display background image using figimage
bg_image = plt.imread('/content/gfglogo.png')
fig.figimage(bg_image, resize=True, alpha=0.5)

plt.show()

Output:

Conclusion

In conclusion, adding a background image to a Seaborn plot can enhance the visual appeal and provide context. The three methods—imshow, set_zorder, and figimage—each offer different ways to integrate images, with imshow allowing precise control over image placement, set_zorder ensuring the image is behind plot elements, and figimage embedding the image directly into the figure background. Selecting the appropriate method depends on the specific requirements of your visualization.