How to reduce PDF size

A similar product takes a 12mb file down to 1.5 mb where your product is leaving it a 12mb.a similar product takes a 12mb file down to 1.5 mb where your product is leaving it a 12mb.

Following code did not help.

// load source PDF file
Document doc = new Document(@"d:\document.pdf");
doc.OptimizeResources(new Document.OptimizationOptions(){
LinkDuplcateStreams=true,
RemoveUnusedObjects=true,
RemoveUnusedStreams=true});
// save output file
doc.Save(@"d:\outFile.pdf");