How do I save all images from .xls file?

I've got a xls file with exactly 167 images that I must save and post on a website. The sheer number itself is painful, but what complicates things is that you can't directly save images from Calc - you need to copy it to Writer first and then save.

This isn't the way I would like to do things, so is there a way to save all the graphics in the file somehow?

1. Open the xls file in OpenOffice or LibreOffice
2. save it as a open document (.ods).
3. rename file to have .zip extension
4. uncompress that zip file

All images should be in a Pictures/ directory in that zip file.

This also works if you are given a .PPT which can be saved in Impress.