I know that I’ll lose some resolution and image quality, but I’m not worried about that. This is about size. How do I get a scanned image in PDF form into a smaller image file (like JPEG)?
Thanks!
What OS?
This is on a Mac.
Open it in Preview, select File > Export, pick JPEG from the file format menu, and you should be good to go.
Awesome! Thanks so much! 
Which is what I asked what OS.
Totally trivial to do on a Mac, not so sure about Windows.
I think on Windows you have to mess about with online converters, but I’m not sure.
Online converters are what I have used when needing to convert PDF’s into nicer things, such as .doc or .ppt. So I assume they will work for .jpeg’s.
Though most people now use .png for images? 
Nope.
Same thing in windows.
Or, File, Save As Other, Images, JPG.
In earlier versions, its just File, Save As, JPG.
I use a screen capture program like Snag It. Snag It creates a simulated printer. Open Adobe Reader and print your pdf to the Snag It printer. Save capture as jpeg.
The advantage here is you are saving an exact printed version of the pdf. All formatting gets processed and saved in the image.
Not that I’ve seen. I mean, it depends on the type of image, but photos and the like are JPEGs. PNGs I basically use for where I might have used GIFs in the past (logos, icons, anything requiring transparency, etc.)
I use Windows so not relevant to the OP but for those that do, there is the very easy to use Snipping Tool
Well, the main reason people use GIF is for animations. PNG handles those (through the .MNG), but that is hardly popular. Yes, most people, e.g. including all your Facebook friends, use JPEG the most. More technical users/those who care will use PNG as it removes most of the disadvantages of JPEG (lossyness) and GIF (limited palette) while maintaining a small size.
Yeah, that’s pretty much the only place I use GIF these days.
If it’s a scanned document in greyscale or colour, chances are the pages are already stored as JPEGs inside the PDF, and if you extract them correctly there will be no loss in quality or resolution. I have no idea whether the methods already presented here extract the JPEGs losslessly, though if you are comfortable using the command line, I can guarantee you that the pdfimages tool from the poppler library will do the trick. (That link is to the library’s home page and includes only the source code, though there are third-party binary distributions for most major operating systems, including GNU/Linux, Mac OS X, and Microsoft Windows.)
Not in Reader. In Acrobat itself, there are a number of ways to convert and exchange files, but Reader XI only offers save to text or a few MS Office formats.
You can, however, copy images to the clipboard and use anything from Paint up to collect that clip and do what you like with it. This preserves the image quality to whatever it is in the PDF, instead of going through any degradation/transformation that screen cap etc. might impose.
For MS-Windows, I use Some Pdf Image Extract to batch extract images from PDFs.
For a GUI tool that uses the same engine, I recommend using Inkscape. Open the PDF, select a page, and then wait for it to load. Then ctrl-click on an image (to make sure it selects it) and Click Extensions > Image > Image Extract.
But I recommend using the previous version, as I’m having trouble with the latest version (at least the 64-bit version).
Before you do this conversion, ask yourself, “why?” Some things are not easily undone, and conversions can cause distortions and loss in quality.