Andrew Murray

The test image that you've added is 721kb - this is a bit large. Here's a test image I've created by modifying [hopper_idat_after_image_end.png](https://github.com/python-pillow/Pillow/blob/main/Tests/images/hopper_idat_after_image_end.png) - it is only 30kb. 

I've just combined the commits in this PR into one so that your original image isn't part of the commit history.

Continuing the suggestion of using `pip install` in the future, https://github.com/python-pillow/Pillow/pull/7760 has now been merged, so that in the next version of Pillow, setup.py will no longer be executable.

> This is how I _think_ it should be fixed: > > * Inject a CFLAG with the value of `[f"--system-header-prefix={sdk_path}"]`. I tried ```diff diff --git a/setup.py b/setup.py index 1bbd2c05c..3a384e38f...

I've created #7827 to resolve this by silencing the warnings.

> Maybe -isystem{os.path.join(sdk_path, "usr", "lib")} will do something No, that also doesn't reduce the warnings.

If it helps, I personally use Python from [MacPorts](https://www.macports.org/) by default, and using that version, these warnings aren't generated.

Valgrind is currently failing - https://github.com/python-pillow/Pillow/actions/runs/5460694184/jobs/9937936242?pr=7260 Also, I went to test the speed of image equality with this, https://github.com/radarhere/Pillow/commit/98e02aa40d607a3c12b4108a72d070b1bd85f060... and found https://github.com/radarhere/Pillow/actions/runs/5461893489/jobs/9940492884#step:8:4787 > Fatal Python error: bool_dealloc: deallocating True or...

If you would like us to help you figure out why your code is using a lot of memory, could you post a short self-contained example script? > one said...

You're running your code over a number of images. Could you pick just one image that you feel is using too much memory, and upload it here?