Since I began using EverNote a few weeks ago, I’ve added alot of information to my account.  Once I figured out a good way to work it into my routines, I found the PDF indexing capabilities particularly useful.  I’ve since added every issue of every MSRC magazine I can find into my Evernote, for it’s superior indexing support.  Now I can simply search for a researcher and find every article at every center that he authored or that mentions him.  However, a few of the sites generate unusually large PDF files (I’m looking at you NAVO Navigator, with your 40Meg PDF). At first I thought there was simply no way for me to get these into EverNote, because of EverNote’s 25Meg limit on entries. After some research, however, I found a way using the Mac’s built in tools to shring these PDF’s by over an order of Magnitude. 

For starters, simply download and open the PDF’s in the built-in "Preview" app.  If you hit the File -> "Save As" menu option, you’ll be presented with the option to Save this PDF to disk, and possibly apply a "Quartz Filter".  The Quartz Filter menu shows some promise, but the built-in "Reduce Filesize" filter completely scrambles the colors, rendering the resulting file unusable.

 

"Save As" dialog The Original (left), and "Reduced Filesize" versions (right)

 So the goal is to create a new Quartz Filter that will still reduce the filesize, but not scramble the colors. [tag:mac][tag:apple][tag:pdf][tag:evernote]

Quartz Filters are controlled and created by the "Colorsync Utility" in the Applications/Utilities folder.  Fire that up, and then click the Plus sign in the lower left to add a new Filter (I named mine "Reduce Filesize by resampling").  Then you can click the little triangle to the right of the filter to select effects to use in that filter.  Our filter will have 2 effects.

The first effect is to simply Resample the Images within the PDF at a lower quality, since that’s where most of the filesize is being used.  So start by adding the "Image Resample" filter.  Then set it to resample at a lower percentage, I chose 25%.

Adding the "Color Image Sampling" Filter

Setting it to 25% resample

Now for the second effect: Colorspace conversion.  In this case, our color scrambling is coming from a poorly managed colorspace conversion.  Now we can add a forced "Convert to Profile" effect to force the document to be in a nice RGB colorspace. (Not the best choice for printing, but good for viewing and compression).  So simply add the filter, and select the "Generic RGB Profile".

Adding the "Convert to Profile" filter

Setting it to "Generic RGB Profile"

And with that, our filter is ready.  Close the Colorsync Utility and return to the PDF Preview, and use the Save As again.  Select your new Quartz Filter, and save the file to disk.  You should see a result like so:

On the right is the original PDF, weighing in at 33.9 Meg.  On the left is the new PDF, weighing in at 3.4 Meg. A full order of magnitude difference in filesize, with little to no visible change.  If you zoom in very far, then you’ll see the images are much blurrier than originally.  However, the text in PDF documents is almost all vectorized Truetype fonts, so they are untouched by this process.  The result is a PDF that’s much smaller on disk, and much faster to navigate (because of the reduced memory footprint).  Also it’s great for EverNote because the 3.4 Meg version streams over the iPhone 3G network MUCH faster. 

So there you have it, a free and easy way to recompress PDF’s.  With the filter created, now it’s a simple matter of previewing the file from FireFox, and then using "Save As" to get an EverNote-ready version of it.