I am trying to make project of a web app that will check the colour of the PDF document. My preferred language is PHP.
At the begining I've been thinking about GD, but this only refer to images (jpg, png, gif). Nothing for PDF. For images I am going to use some method similar to this: Get image color.
So does anyone know some method, library (opensource), or something else to make such app? I can't find any examples on the web.