I'm working on a project and i'm not really experienced with this. I want to make a plugin where users can upload only .eps files. But there's a catch...
The user can only upload .eps files and these files can not have transparant color in it. I thought of something to search for specific transparancy value and if they are there the plugin won't accept the file. But actually i don't know anything at al about .eps files. I hope somebody can teach me the basics or help me find the terms i have to look for in the file to not accept it.
I have made 2 .eps files one file contains a transparent color the other doesn't. I've noticed that the file which does not is much shorter. Also the file with transparency in the color has a fall back image and is much longer. Is this because of the transparency color or are there other things. I will ad the screenshot of the difference between the files.
PostScript doesn't have any real notion of transparency. If you are seeing transparency in the output then most likely the transparent content has been rendered to an image, and the EPS includes the image instead.
Your EPS programs clearly started life as PDF files and the portion you have pointed to is nothing to do with transparency at all. That line alters the current transformation matrix and does a gsave, that's all.
But in short, if you want to forbid transparency in an EPS file then you need do nothing at all, PostScript (and therefore EPS, Encapsulated PostScript) cannot contain any transparency.