First step is to make sure you have Perl installed and the Perl module Image::Size. Then all you need is to add this to your vimrc. " Get image size with F4 with perl Image::Size module. function! PerlImageSize() g/src normal $ normal N normal 2w perl << EOF use Image::Size; $jo = VIM::Eval("expand('')"); $size = Image::Size::html_imgsize("$jo"); VIM::Eval("setreg('a', '$size')"); EOF normal $ normal "ap endfunction nnoremap :call PerlImageSize()