Is it possible to compress pdf using php?

Question

PHP

Is it possible to compress the finished pdf file using php? (For example reduce images to the right size/quality and return an already resized pdf)
Without using third party APIs and libs that use third party APIs.
If not, then in what language do such operations usually take place?

Answer 1

Google ps2pdf (no, not ps2pdf.com, but this utility that works with GhostScript).
It is easily installed on any Linux server and with one command (you can do it out of puff) presses the proposed file according to the necessary requirements (-dPDFSETTINGS=/ebook, for example).

Answer 2

pdf is the final format, its compression or other processing is not expected

Answer 3

Unless, irritate, reduce and "dragonize" back