I am a big fan of the Preview application that is the default PDF/image viewer in Mac OSX. Discovering that I could use it for scanning was a revelation that might have included a bit of a jig. And the signature feature… brilliant!

But there is one thing about Preview that has always bugged me; when you scan a document as a PDF, the resulting image size is far bigger than necessary. And there is no native way to make it smaller without making the document virtually unreadable.

I finally got annoyed enough by this that I took the time to search for a solution. As is often the case, it didn't take long to find that some really helpful soul had come up with one and was willing to share it.

And the answer is: install some Quartz filters that you can use to reduce the size of the PDF files without making them unreadable. Mind you, I don't have a particularly good grasp on what a Quartz filter is, but you don't have to to take advantage of this.

There is a good post here by Rogier at Scooter-IT with more details than I am going to include, but here is the short version (I can confirm only that this works like a charm in OS X v10.7.3).

1) Download these filters that Jerome Colas was kind enough to create and make available: download here.

2) Put the filters folder from the download in the Library folder of your startup disk (you'll wind up with Macintosh HD/Library/Filters if you haven't renamed your hard drive) - Be sure to put them here and not in the /System/Filters folder, since that folder should be reserved for Apple approved files according to Jerome Colas here.

3) Next time you want to make a PDF smaller, open it with Preview, choose Export… from the File menu and then select the quartz filter (I like 150 DPI Average Quality). You can either save it as a new PDF or simply replace the original with the smaller file.

How much does it help? I reduced a scanned signature page from 7.9 MB to 190KB without a meaningful reduction in image quality using the 150 DPI Average Quality - Standard Compression filter. I haven't tried it with a PDF that has images in it, so YMMV with those.

Now, I suppose I could learn to scan better or use a different app for scanning, but I can't come up with a very good reason for doing that now that I can so easily make my scanned PDFs a friendly file size.

So, if you are taking advantage of the document management or journaling built into Proof Admissions, or the ability to attach documents to emails with fmSpark, this could really help to keep your document file size manageable.