XeTeX ⇒ Large Output PDF Size with included Images

[tafi]

I'm typing up my thesis using xelatex and am having trouble understanding how my output files can be as large as they are.

As an example I am currently working on one chapter which comes to 61 pages. the images to be included are exclusively PDF or PNG format and the total file size of all images is less than 1.82MB (the maximum image file size is a 200kB PNG)
I'm using the graphicx package.

When I compile with the "draft" option (to give a file with only text and image bounding boxes) the size of the output PDF comes to 318kB which seems reasonable to me for this length (I suppose it could be smaller).

However when I complile a final version (including images) the output PDF file size jumps to 3975kB

A bit of simple maths tells me that the sum of the text and images is 2.1MB and this is the upper limit of what I expect the file size to be. So the final PDF is actually 1.8MB more than reasonably expected.

Xelatex (or xdvipdfmx) has picked up an extra 1.8MB from somewhere in the process of including the images. Does anyone know how this might happen and whether there are any options to improve the image handling?
If this carries over to the rest of my 200+ page document, the end product will be huge.

PS: I have tried using PDFlaTex as well. It produces a similarly sized file (~4MB) (and that's from a first initial pass - without including the bibliography).

[Stefan Kottwitz]

I would use the original big PDF output for the printed version.

To get a smaller electronic PDF version for emailing or archiving, intended to be read on screen, have a look at pdfsizeopt.

Stefan