Size of pdf generated from crystal report...

I have a crystal report which I export to pdf-format using either the ExportToDisk or ExportToStream method of the ReportDocument class. The space required for the pdf-encoding in both cases (not surprisingly) is the same, but it seems the size is bigger than it needs to be. I already have some pdf-files looking almost the same as the ones I am making from the crystal report (actually the crystal report was designed based on the look of these pdfs), but these are only 25% of the size. These pdf-files contain more or less the same data that mine does and in addition contains a logo which I don't have. The resolution of the documents also seem to be the same, at least I am not able to spot any difference. Is there any way that I can reduce the size of the pdf I generate from the reportdocument