Save the high-res image

This example shows how to plot random data on the brain and save it as an image file.

Render the image

The brain_plot function renders the image based on data v and returns a NumPy array. The Numpy array has a np.float64 dtype, and the range of its values is 0–1.

import numpy as np
from brainplotlib import brain_plot

rng = np.random.default_rng(0)
v = rng.random((1175, ))

img = brain_plot(v, vmax=1, vmin=0, cmap='viridis')

print(img.dtype, img.shape)
print(img.max(), img.min())

float64 (1560, 1728, 4)
1.0 0.0

Save the image

The rendered image can be saved using the package of your choice:

Using matplotlib

import matplotlib.pyplot as plt
fig = plt.figure(
    figsize=(img.shape[1] / 200, img.shape[0] / 200), dpi=200)
ax = fig.add_axes([0, 0, 1, 1])
ax.imshow(img)
ax.axis('off')
plt.savefig('save_image_matplotlib.png')
plt.close()

Using Pillow

from PIL import Image
im = Image.fromarray(
    np.round(img * 255).astype(np.uint8))
im.save('save_image_pillow.png')

Note

The code block above requires that the Pillow package has been installed.

Using OpenCV

import cv2
## The default channel order of OpenCV is BGR rather than RGB.
reorder = {3: [2, 1, 0], 4: [2, 1, 0, 3]}[img.shape[2]]
cv2.imwrite(
    'save_image_opencv.png',
    np.round(img[:, :, reorder] * 255).astype(np.uint8))

Note

The code block above requires that OpenCV and its Python bindings to be installed.

Comparison of saved images

Using matplotlib

Using Pillow

Using OpenCV

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