Bug summary

When using imshow with interpolation='none' and then saving the figure to PDF using savefig(), the PDF file output does not match the screen/notebook output. It appears that interpolation is still being applied to the PDF output. This bug is manifested only with 'none' interpolation with PDF filetype output. Setting interpolation to None or 'nearest' gives the correct result with PDF output (and screen/file match). PNG, JPG, and SVG output filetypes all produce the correct results. MWE below.

Code for reproduction

import numpy as np
import matplotlib.pyplot as plt

data = np.zeros((25, 25))
data[8:16, 8:16] = 100

fig, ax = plt.subplots()
ax.imshow(data, interpolation='none')
fig.savefig('output.pdf')

Actual outcome

Notebook/screen output (correct):

PDF File output (incorrect):
output.pdf

Expected outcome

The output PDF file would not have interpolation applied (matching the screen output).

Additional information

No response

Operating system

macos

Matplotlib Version

3.7.1

Matplotlib Backend

module://matplotlib_inline.backend_inline

Python version

3.11.2

Jupyter version

6.5.3

Installation

pip