From c23c9c0bf421b8661ae8bc9991090847c25576df Mon Sep 17 00:00:00 2001 From: Andrew Date: Mon, 22 Jul 2024 10:48:41 +1200 Subject: [PATCH] Note that higher levels are not guaranteed to be better --- README.md | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 007cc7bd..c39c234b 100644 --- a/README.md +++ b/README.md @@ -66,7 +66,12 @@ More advanced options can be found by running `oxipng --help`, or viewed [here]( Some options have both short (`-a`) and long (`--alpha`) forms. Which form you use is just a matter of preference. Multiple short options can be combined together, e.g.: `-savvo6` is equivalent to to `--strip safe --alpha --verbose --verbose --opt 6`. -Note that all options are case-sensitive. +All options are case-sensitive. + +Note that oxipng is not a brute-force optimizer. This means that while higher optimization levels +are almost always better (or equal) to lower levels, this is not guaranteed and it is possible in +rare circumstances that a lower level may give a marginally smaller output. Similarly, using Zopfli +compression (`-Z`) is not guaranteed to always be better than without. ## Git integration via [pre-commit]