How to measure anything with a camera and software

20 Comments

IphotomeasureQuick, when I say iPhoto, you think of what. Apple, right? Difficult as it may be, forget Apple for a second and add the word "measure" as in iPhotoMEASURE. What is it? Well, what if I told you that you could use a digital camera, even a cell-phone camera, along with some software to measure any items you can snap a picture of? The solution is the iPhotoMEASURE application that I just heard about. Although it’s really geared towards contractors, Realtors and the like, there’s a number of consumer applications that make this a compelling product.

DigitargetFirst off, the "secret sauce" of the solution is called a "DigiTarget". The DigiTarget gives everything in your photo a frame of reference; it’s a single sheet of paper with a 7.5 x 7.5-inch square on it. A 15-inch square version is also available for outdoor measurements. Simply print off a free DigiTarget, affix it to something in your photo scene and snap a pic. The iPhotoMEASURE software uses the DigiTarget to compute the measurements of items in your photo and the company claims that any distance in the picture can be measured with up to 99.5% accuracy. Conceptually, it makes sense since the software has that 7.5- or 15-inch frame of reference.

I can definitely see the benefit to contractors that need measurements to accurately quote a job or price materials. Same goes for those in real estate, interior design, etc. From a consumer standpoint, can you imagine heading to Home Depot or Lowes with a photo printout of your new home improvement project? I thought I impressed the Home Depot folks when I did something similar with OneNote Mobile and my UMPC, but I had to manually measure everything and then ink it on the picture.

How about furniture shopping? Snap a pic of your room measurements, bring your camera to the furniture store and click, click, click to your hearts content. When you get home, you can measure up the best pieces and see if they’ll fit; no tape measure needed.

On the FAQ page, you’ll see plenty of details about the software. I noticed that you can use a cell-phone camera but only for close up scenes. The company recommends a minimum of 2-megapixels up to around 15-feet; after that, you’re better off with 4-megapixels or greater. All of this accuracy and measuring goodness does come at a price: the software will set you back $99.99 if you download it; $20 more gets you the software on CD plus a few more goodies. The software is available for both PC and Mac.

How well do you think it works? I suspect it works well, but I’ve requested an evaluation copy. If I see that come my way, we’ll put it through the paces right here.

20 Comments

aziz

if i have tailor shop can this help me to measure my customers body from their pictures without any need for their visit to my shop?

greg

you can do the exact same thing with Adobe Professional acrobat. Just set a ruler in the picture , take photo and scale it to size with the ruler bar on the software program and it is very accurate as long as to point and click at the right points.

Dragonheart

From most of the comments I must assume that most have not actually tried this program, as I have.

First you do have to shoot photos straight on as this program was designed to measure in a single plane. As far as accuracy I was able to scale overall measurements of up to 16 feet and be within 1/2″ of the actual measurement.

Now for the down side. I was using a 10.1 megapixel camera and the high resolution photos that were downloaded into the program were cropped on the right side by about 25%. So if you are using the program to get an overall measurement from an interior room wall photo you are SOL as the right side of the photo is not there. Even though the program advertises it works with all cameras, apparently it does NOT! The program doesn’t work well with high resolution photos. The manufacturer is aware of this problem. Additionally, storage and retrieval of measured photos is an issue.

The program is a good idea, but it definitely needs work and more features added to make it worth trying. I have to say I am amazed at all the editors that were willing to give this program a thumbs up without really putting it to the test.

Lars

Hey folks,

I’ve been following Iphotomeasure since it’s inception in November, and I’ve yet to come up with a straight answer on how it works. Having read more about photogrammetry and digital imaging than I care to, it seems to me that for someone with low accuracy requirements and point and click functionality, it’s not a bad deal. However, they claim they can measure to 1/32″ with the right camera a single point perspective, but I’m not convinced. I agree with the comments on perspective and barrel/pinhole distortion. If anyone has more detailed analysis, I’d love to hear it. FYI…they’re looking for investors. I’ll be curious to see if they Angel community feels as confident about their applied for patent as they do.

http://www.pitchtheangels.com/pp/com.php/article/o/archive/ct/presenter/oid/21

nex

Re: everyone who wondered if it takes perspective into account: No, of course not! The makers of this software are complete idiots who never tried their product out in the real world! Duh …

Anyways, yes, you can do the same thing, and much more, in a multitude of other applications (Blender, Canoma, Photoshop, …), some of which are free. But they’re not specifically made for this simple task and harder to use, so I don’t think this app is not completely pointless. On the other hand, who can imagine a DIY situation in which it would really be worth its price? The “furniure shopping” use case is just a joke, it would be far more convenient to just take measurements manually, or look them up online. But for contractors … yeah I can see that. And as a business expense, 120,- is really not that bad, measuring devices with sharks and lasers also cost money.

Emil

Hmm, interesting but it would be much better if they could make a Cell phone app to do the same. Snap a picture with your cell phone camera and run in against this app. No need to wait till later.

Ken

It seems that in order for this to work, one would need a stereo picture. Meaning that one would need two cameras, a fixed (and known) distance apart, take a picture at the same time. Then I would believe that this would work very very well. Without stereo, I don’t see how it could accurately consider depth.

BWilde

“I impressed the Home Depot folks…”

Yes, whenever I go there, that’s what I always strive for, too. Makes my life complete.

Peter

Let alone perspective — does this take into account barrel/pincussion distortion? A cheap digital camera on “wide angle” sucks for architecture shots. If it does take perspective into account then it must extrapolate it using straight lines in the picture, but that extrapolation would be affected by distortion.

Jim

Interesting software but an unnecessary expense since there is a totally free image processing and measurement program, used by many scientists, called ImageJ. Java-based, available for either Macs or WinPCs, it is available via the Center for Imaging in Education (CIPE) at evisual.org. It is also available through that same website in a non-Java format as NIH Image for Macs or Scion Image for PCs. The only necessity is that, when one takes the photograph, there must be an item of known size (e.g. a meter stick) for setting the scale.

Stuart

SketchUp has a new feature that allows easy photo mapping onto objects – it will give the same measuring capability after it has been put together.

Stuart

Malcolm

Google Sketchup allows you to:
1) import pictures
2) size pictures and other objects by measuring an edge and typing a value (in distance) that the edge should be – the software will scale the model/pictures/etc. for you.

Seems like you could steal this idea and use Google Sketchup (which is free) to do the same sort of thing, though you would not have the added benefit of processing for perspective.

thebin

While this is cool, it seems a lot to charge for a relatively simple piece of software. I wrote something called OpenTrack2d which I posted on SourceForge.net which basically does the same thing. Given that you have a calibration frame, you can track points in a video to determine relative positions, velocities and accelerations. It’s basically like VideoPoint, but with more options. Unlike iPhotoMeasure, it won’t give you the point to point measurements on clicking (you get them after the fact), but it would be exceedingly trivial to add this feature. The current users of OpenTrack2d are kinesiology students at West Chester University in PA.
And yes, my software and iPhotoMeasure were written for different audiences – but that doesn’t change my point that iPhotoMeasure costs a lot for minimum capabilities.

William

Yes – it must take foreshortening into account. Briefly what it does is calibrate the camera’s parameters (field-of-view for one) from the reference DigiTarget image which has known dimensions, and generates a perspective transformation from that. This should be a simple exercise in computer vision.

Notice how it only measures horizontal and vertical lengths. This is because these have particularly special invariance properties under a perspective transformation.

This leads me to deduce that the DigiTarget must always be shot head-on for this thing to work at all.

Scott Brickey

does it take perspective into account at ALL?… who says that it can accurately measure an oil drill rig when the “reference” piece of paper is 10 feet in front of it? (as one very basic example)

Jason

It’s nice that they’re selling software to the “common man”, but this is something contractors have been doing for ages. Get custom countertops made…the first thing you’re likely to see is someone stick little sheets full of varying size circles all along your cabinets and counter. Having multiple sheets neatly covers the issue of perspective as well. If they supported multiple reference cards throughout the image to help maintain consistency, i’d readily spend the $100. As it stands, it’s barely more than a toy.

jtheory

Not so simple — doesn’t it have to do some processing to deal with perspective? It’s not so useful if you photograph a square rug and it tells you the close side of the rug is 8′, and the far side of the rug is 6′. In that example photo of a house, the surfaces are not all the same distance from the camera.

Keith

Or you could try it the DIY way: make your own 5 x 5 square, put it in pics for reference, then use a calculator or Excel plus your image editing software of choice to do the same extrapolations that the software is doing (ie if the paper is 20 pixels wide in your picture, then each pixel is 1/4 inch).

Comments are closed.