Comment 5 for bug 1669734

For reference, bug referred is
«Fixed bug #45030 (Destination image alpha channel noise when using imagecopyresampled). (Pierre)» from php-5.3.0beta1 release notes.

I was able to find a copy of the commit here https://repos.bgemi.net/sikofitt/php-src/-/commit/a3383ac3d7e21e54b1d7d89f308088d0692abc9f .

You'll have to compare the source and check if it is not fixed on Ubuntu's package, or if it is a new, unrelated bug.