Harry Mustoe-Playfair

Very strange, using two different versions of the extension with the same version of PHP I get different results: ``` PS C:\Users\harry\web\htdocs\test\tiff testing> php .\tiff_test.php OS Family: Windows PHP Version:...

Latest PHP version and Imagick version: ``` PS C:\Users\harry\web\htdocs\test\tiff testing> php -v PHP 8.4.14 (cli) (built: Oct 22 2025 08:49:43) (ZTS Visual C++ 2022 x64) Copyright (c) The PHP Group...

After some more digging, this appears to have been introduced in version 3.6.0 of the extension: ``` OS Family: Windows PHP Version: 7.3.24 Imagick Module Version: 3.4.4 Imagick::getVersion(): ImageMagick 7.0.7-11...

So the issue is not present in extension version 3.5.1, but is present in extension version 3.6.0. Looking at the diff between tags 3.5.1 and 3.6.0-RC1 (only tag available for...

As I'm not a C programmer and don't really understand the link between imagick and imagemagick, I've been leaning on good old copilot to look at this... After going through...

After some more investigation, **this is not isolated to Windows**. When compiling imagick against the latest ImageMagick version in ubuntu 24 I get the following: ``` OS Family: Linux PHP...

And just to note, compressing using the exact same version from the CLI nets correct compression: ``` /mnt/c/users/harry/web/htdocs/test/tiff_testing$ magick -version Version: ImageMagick 7.1.2-7 Q16-HDRI x86_64 23405 https://imagemagick.org Copyright: (C) 1999...

After filing an upstream bug report it would appear that the MagickWand api is doing the correct thing: https://github.com/ImageMagick/ImageMagick/issues/8408 So this must be an issue in the link between PHP...

## AHA!!! Problem solved! Over in the imagemagick repo, @snigbo correctly identified that I should use MagickSetCompression instead of MagickSetImageCompression: > I don't use or know PHP or IMagick, and...