I can't seem to find any way of finding out the DPI of images in my word document. They vary greatly and I need to re-insert all images at 300 dpi or higher (the PDF writer will down-sample to 300 if higher).

I figure I can do it manually if I copy an image where I know the pixel dimensions (say 600 pixels wide) and work out the maximum size in the document (ie 2 inches wide), and then paste it into the document at no larger than this calculated size.

Will this method ensure all images will retain their quality ? Or will word mess about with the resolution internally ?

Please help... I have a document with over 500 images I need to fix.