online measuring ruler

Hi everyone
I really need your help, i have many many pictures of various things and i need to measure the distance between them. for example i have a picture of building as a centre point and i need to measure how far it is from say a car parked next to it. So i basically need an on line measuring tool where i can click on the building and then drag the mouse to the car and it will give me a measurement in millimetres on the screen I know such a program exists as have seen it used before but i don’t know the name?
Please help me. Thank you
Answer #1
sounds like some type of Autocad program, but not sure
Answer #2
If you import your *.jpg file into one of those drawing programs ( something like Corel Draw, for example ), then you can put the screen into various “modes” that will give you grids ( like in mm, inches, pixels, etc. )
Answer #3
if u search in google “on screen measure tools”, it gives some decent results.
here’s some page that i find intriguing from the search results-
http://www.articpost.com/how-to-measure-pixels-on-a-screen/
http://www.researchism.com/2011/04/free-tools-measure-screen-area-pixels.html


http://www.freewareplanet.net/measure.php
among these “Meazure” seems like a good tool.
Answer #4
Try this
http://arohatgi.info/WebPlotDigitizer/