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.

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

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.

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.

And, er, iPhotomeasure guys – can I say ‘metric?’

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.

“I impressed the Home Depot folks…”

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

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.

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.

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

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.

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.

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.

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)

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.