Improve PHP PDF merger

I'm using the PDF merger for PHP which can be found here: [login to view URL] When adding multiple PDF's which contain each the same font, the combined PDF contains multiple times the font, thus making the file bigger. When adding more files (sometimes +100 PDF's) this really is a problem. I'm looking for a solution which provides me a single PDF containing all individual PDF's and the font only one time. Preferably not by altering the file after merging, as this can be time and resource consuming. About the files: - [login to view URL] / [login to view URL] / [login to view URL]: three different PDF files with usage of the same font - [login to view URL]: result from PDFMerger (which includes the font three times) - [login to view URL]: expected result (which includes the font one time) By opening the file properties in Adobe Acrobat, you can easily see the used fonts in the document. Your solution can be made open source after completion.