I have a pdf file that consists of an image per page.
Are there any command line programs that can extract these images?
If it's just image per page, you can just rasterize the pdf, for instance, with imagemagicks' convert -density 300 test.pdf test.png where 300 is in dpi.
However, this doesn't get the original raw image out, for that, you need something else - waiting for a better answer.