I couldn't find any guide to tell me how to produce optimized images in php environment. I have a website under linux, with php, and cannot install* anything.
Somebody suggest the use of exec, lot of people in github seems to have developed some wrapper... but I cannot undertand how to place this softwares in my web space. For example jpegtran (which I use in windows as a stand-alone executable) probably doesn't work on my server.
Can somebody tell me how to proceed - if it is even possible?
EDIT
(*) I have no rights to install anything in that server. I can "install" php packages (e.g. wordpress ecc.), I have access to ftp. I found out that even executables cannot be run. This seems to be a losing battle.