Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

The are places that prefer PDF's for printing, and we've also been using PDF as a distributable format that "everyone can open". It's very easy on a mac to save as PDF (or go to "print" and save it as pdf from there) but there are no options presented about how things should be stored.

My question regarding images within pdf:
In what format are images stored within a PDF? Does PDF just wrap around the existing file (embedded) or does it convert it to some other format for storage? Is there any image compression (such as jpeg) or data compression (lzw, zip, etc) applied to the image?

share|improve this question
up vote 3 down vote accepted

Normally all image content in a PDF is embedded in the file. But PDF allows image data to be stored in external files by the use of external streams or Alternate Images.


in case you're looking for a way to extract images form a PDF, here's a little freebie that makes it a walk in the park:

With Some PDF Images Extract you can capture the images from the PDF and save them into many different formats, including JPEG, PNG, TIFF, GIF, and lot more.

alt text

Tutorial: Extract images from PDF files to TIFF, JPEG, etc

share|improve this answer

Wikipedia has a nice writeup on the PDF Image model. It discusses briefly how both vector and raster can be stored. Raster images are typically embedded as 'XObjects' and can compressed using a variety of algorithms (LZW, JPEG, zip)

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .