pyssim

This module implements the Structural Similarity Image Metric (SSIM). Original code written by Antoine Vacavant from http://isit.u-clermont1.fr/~anvacava/code.html, with modifications by Christopher Godfrey and Jeff Terrace.

Installation

pip install pyssim

Running

$ pyssim --help
usage: pyssim [-h] image1.png image path with* or image2.png

Compares an image with a list of images using the SSIM metric.
  Example:
    pyssim test-images/test1-1.png "test-images/*"

positional arguments:
  image1.png
  image path with* or image2.png

optional arguments:
  -h, --help            show this help message and exit
  --cw                  compute the complex wavelet SSIM
  --width WIDTH         scales the image before computing SSIM
  --height HEIGHT       scales the image before computing SSIM

Compatibility

pyssim is known to work with Python 3.9 to 3.13.

Development

To run from a local git client:

PYTHONPATH="." python ssim

To run the lint checks:

pylint --rcfile=.pylintrc -r n ssim setup.py

To test:

$ PYTHONPATH="." python ssim test-images/test1-1.png "test-images/*"
test-images/test1-1.png - test-images/test1-1.png: 1
test-images/test1-1.png - test-images/test1-2.png: 0.9980119
test-images/test1-1.png - test-images/test2-1.png: 0.6726952
test-images/test1-1.png - test-images/test2-2.png: 0.6485879

References

• [1] Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli. Image quality assessment: From error visibility to structural similarity. IEEE Transactions on Image Processing, 13(4):600--612, 2004.
• [2] Z. Wang and A. C. Bovik. Mean squared error: Love it or leave it? - A new look at signal fidelity measures. IEEE Signal Processing Magazine, 26(1):98--117, 2009.
• [3] Z. Wang and E.P. Simoncelli. Translation Insensitive Image Similarity in Complex Wavelet Domain. Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on , vol.2, no., pp.573,576, March 18-23, 2005