This code was for a BB Code mod here:
https://vborg.vbsupport.ru/showthread.php?t=90869
But that doesn't work for VB 4 and it hasn't been updated. By default you can't use multiple options in vBulletin BB Codes, but if you want to control height and width you could make the following:
imgsize
Replacement: <img {option} src="{param}" />
Example: [imgsize="width='100' height='200'"]http://... url ...[/imgsize]
You will get a warning from vBulletin but you can hit continue and it will work.
Warning though- this could be a little dangerous- someone who knew what they were doing could exploit it to run arbitrary HTML.