apply_poisson_noise

photutils.datasets.apply_poisson_noise(data, seed=None)[source]

Apply Poisson noise to an array, where the value of each element in the input array represents the expected number of counts.

Each pixel in the output array is generated by drawing a random sample from a Poisson distribution whose expectation value is given by the pixel value in the input array.

Parameters
dataarray-like

The array on which to apply Poisson noise. Every pixel in the array must have a positive value (i.e., counts).

seedint, optional

A seed to initialize the numpy.random.BitGenerator. If None, then fresh, unpredictable entropy will be pulled from the OS.

Returns
resultndarray

The data array after applying Poisson noise.

See also

make_noise_image

Examples

from photutils.datasets import make_4gaussians_image
from photutils.datasets import apply_poisson_noise
data1 = make_4gaussians_image(noise=False)
data2 = apply_poisson_noise(data1, seed=0)

# plot the images
import matplotlib.pyplot as plt
fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(8, 8))
ax1.imshow(data1, origin='lower', interpolation='nearest')
ax1.set_title('Original image')
ax2.imshow(data2, origin='lower', interpolation='nearest')
ax2.set_title('Original image with Poisson noise applied')

(Source code, png, hires.png, pdf, svg)

../_images/photutils-datasets-apply_poisson_noise-1.png