Grayscale ========= Usage: `grayscale()` Description ----------- This filter changes the image to grayscale. Arguments --------- No arguments. Example ------- .. image:: images/tom_before_brightness.jpg :alt: Picture before the grayscale filter :: http://localhost:8888/unsafe/filters:grayscale()/https%3A%2F%2Fgithub.com%2Fthumbor%2Fthumbor%2Fraw%2Fmaster%2Fexample.jpg .. image:: images/tom_after_grayscale.jpg :alt: Picture after the grayscale filter