This is probably hard since most product shots are perspective, but it would be awesome if I could point to an image at some online store and type in the dimensions and you scaled that photo to actual size.

Here's a product category where it'd be useful (and where the photos are mostly straight on): http://www.amazon.com/Canon-PowerShot-SD1000-Digital-Optical...

Let's say you are buying a watch, amazon has images, but those are not actual sizes; although amazon lists the dimensions separately. Having the actual image size would, in my opinion increase sales in this category.

Also, check if you can integrate any of this with like.com.

Good idea, good luck!

If I could figure out the bounds of the product (in the image), then I could automate the whole process.

Also, might be nice if you had some presets like, say, Macbook, Macbook pro, etc.

Maybe have such a system as a back up, for fine tuning. Credit card would work for me, I always have some odd card in my wallet with me.

It stores the ppi (pixels per inch) of the image, and the ppi of the screen and scales accordingly

Also, forget the "screen size" thing. Just use physical measurements in CSS ("width: 1cm") - it works remarkably well on a variety of browsers.

If it furthers the matter, I'm on a ThinkPad T60p (15" UXGA), XP, Google Chrome (verified in Opera as well)

Pretty cool site, though. I was pleased that the several things I tested were sized as accurately as they were.

You remember that graphic a long time ago that uses to be on the web that showed the relative sizes of different spaceships (like star trek enteprise etc). That was amusing, and if you had something like that regularly coming up, I'd put you in my rss feed. Amuse me.

But otherwise, it's really nicely done, and it does what it is supposed to do properly. I like it.

(Just think of adding some reason why I would want to go back)

Would be helpful to build up a product comparison database, so that I can compare the new cellphone I am thinking about buying to my existing phone to get a real-world idea of the dimensions.

Suggestion for allowing people to catalog their own stuff: create a printable template that I can print out and photograph my object along with a reference item (us dollar, quarter, etc). Between the reference item and the printed grid you should be able to work out the dimensions of the photographed object. You could probably get a massive social effect from people photographing and cataloging their various objects.

Do you have cookies disabled ?

Yes, it does scale based on the monitor size to give you the actual size.

Nicely done!

Maybe have the threshold for abuse a bit higher (I added the giant cookie and reported it for abuse).

To calculate the DPI it uses the screen resolution (pixels) and your reported screen size (inches), if either is missing it would fail to work (for now).

Update: Safari does report it, so it looks to be another issue. Perhaps a bug in the scaling for Safari?

Edit - It might be the way Safari handles onload - https://bugs.webkit.org/show_bug.cgi?id=13241

Perhaps might have some traction in the 'adult entertainment' category.

To calculate the DPI it uses the screen resolution (pixels) and your reported screen size (inches), if either is missing it would fail to work (for now).

I'm not sure if that can be disabled or not or is system dependent. (I'm assuming every system reports it correctly as of now).

If your system reports the resolution correctly here - http://andylangton.co.uk/articles/javascript/browser-screen-... - then it must be some other bug.

Other than that, a very nice website.