Extract images from PDF without resampling, in python?

Question

How might one extract all images from a pdf document, at native resolution and format? (Meaning extract tiff as tiff, jpeg as jpeg, etc. and without resampling). Layout is unimportant, I don't care were the source image is located on the page.

I'm using python 2.6 but can use 3.x if required.

thanks

Summarized Responses

There is a JPedal java library which does this called PDF Clipped Image Extraction. The author, Mark Stephens, has a concise highlevel overview of how images are stored in PDF which may help someone building a python extractor.

For pdf's which have jpegs stored in place "as is", Ned Batchelder has a quick and dirty jpeg extractor.

Answer 1

Often in a PDF, the image is simply stored as-is. For example, a PDF with a jpg inserted will have a range of bytes somewhere in the middle that when extracted is a valid jpg file. You can use this to very simply extract byte ranges from the PDF. I wrote about this some time ago, with sample code: Extracting JPGs from PDFs.

Answer 2

There is an article explaining how images are stored inside a PDF at http://pdf.jpedal.org/java-pdf-blog/bid/27708/Understanding-the-PDF-file-format-how-are-images-stored

Answer 3

Libpoppler comes with a tool called "pdfimages" that does exactly this.

(On ubuntu systems it's in the poppler-utils package)

http://poppler.freedesktop.org/

http://en.wikipedia.org/wiki/Pdfimages