Bonnie Bilski shares a tip on extracting image data from a PDF to use in another file type.
"Sometimes clients or vendors provide you with PDF files instead of DWG files, and you need to get the data out of the PDF and into your drawing or report. The following steps explain how to extract an image from a PDF document so you can place it in an AutoCAD drawing file, a Word document, a presentation, etc.
1. You must have Adobe Acrobat installed on your hard drive.
2. Once you have opened the PDF, choose Tools > Select & Zoom > Snapshot Tool
3. Click the upper-left corner of the image or figure you want to copy, and hold the mouse button down while you and drag a rectangle around it. Release the mouse button and Acrobat will copy the selected area to the clipboard.
4. Paste the image or figure into an AutoCAD drawing file or other type of file.
You can manipulate the sharpness of the pasted image by increasing or reducing the magnification of the image."
Notes from Cadalyst Tip Patrol: PDF files are common file formats that are used throughout the design world. They aren't that easy to work with, however, if you need to use the data contained in them.
Using proprietary software that can edit PDF files, like Adobe Acrobat, is a great way to go. Not only can you select portions of the PDF file and copy them, you can also extract image files from the PDF. You can even convert PDF files into other image types (like JPG or TIF). AutoCAD can reference PDF files directly into your model or drawing as an overlay (if you lack access to Adobe Acrobat, you can work with them this way). If the PDF was made from another AutoCAD file, and was made with AutoCAD's print-to-PDF tool, then the linework will retain its layering and you can snap to the objects.
Plotting AutoCAD files to PDF using AutoCAD's tools is a great way to protect your data when you send it to outside groups; it provides the data in a form others can work with, but protects it at the same time. You might also want to try DWF files.