Measure Anything with a Camera and Software 208
Kevin C. Tofel writes "Using a simple concept, iPhotoMEASURE software can measure any objects you can take a picture of. Include a printout of a 7.5- or 15-inch square in the photo and the software can measure any distance or object in the pic to within 99.5% accuracy. Although geared towards contractors, there's any number of consumer usage scenarios as well. Enough to justify a $99 price tag? Jury's still out on that."
Re:Unfortunately... (Score:3, Informative)
It might have to do something trickier. If you look at their example:
http://jkontherun.blogs.com/.shared/image.html?/ photos/uncategorized/iphotomeasure.jpg
They measure objects that are two distances from the camera. (The garage, and the windows on the house which are a few feet forward). Since they are closer, they would appear to the camera as slightly larger, making the software inaccurate. So, either the software doesn't work, or it does do some trickery.
Re:Not practical. (Score:5, Informative)
No matter how many times you go out to a job site to measure and verify things, something always comes up that requires you to go back. For this reason, we take a lot of pictures in hopes that the camera will catch something we might not be looking for at the time.
I can't begin to count how many times I've counted bricks in those pictures to estimate distances. If I had software that could look at the image and provide measurements with 99.5% accuracy, that would be extremely useful. At $99 it would probably pay for itself after three or four uses just on time saved going back out to the site.
=Smidge=
tax on people who can't do math (Score:4, Informative)
But what really gets me is the claim in the advert, claims that hyperbolic if not outright lies. I can easily construct a photo in which a house appears to be the same dimensions of the squares. One more effective way to do what the software is proposing is to know the dimensions of a feature that is part of the object you wish to measure, and use similarity to approximate the dimensions of the smaller or larger object.
Two dimensions only ??? (Score:1, Informative)
First of all, If I can put a sticker on it, why not just measure it ? Second of all, for this to be at all usefull it would need to be able to measure in the micro (100ths of a millimiter) or macro (100s of meters) domain, and also be able to compute the size of any object in the distance based upon the size of an object in the foreground. I thought I was going to read how some clever mofo had figured out paralaxing or something, but no. Basically this is $99.00 for a pixel counter !
Stupid.
Waste of money! (Score:5, Informative)
Re:Expensive (Score:1, Informative)
Let's say you have 10 projects in the next year where this software would save you 2 hours of manual labor on each project. If you paid that manual labor anything more than 5 dollars an hour, this would be worth the investment. I'm surprised they aren't charging more. Perhaps even making an online service out of it and charging per use.
Typical, though: "All software should be free!"
Re:I think that's the marketing dept. (Score:2, Informative)
So the "hard" part in this software remains to automatically (hopefully it is automatic) find the DigiTarget and calculate a "more or less affine" transformation matrix and then calculate the distance with regard of the found matrix (this does not resolve distorions and assumes a pinhole camera, but there is not much else doable with only one picture and a small known target).
The situation would change if they took at least two pictures of the scene from two slightly different positions, with at least one including the "DigiTarget". Then all the information would be available to really do the measurement as long as the user defines the distance that is to be measured in at least two of the pictures (and there are 5 additional points that can be matched between the two pictures, which is typically automatically feasible)
Re:I think that's the marketing dept. (Score:2, Informative)
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.
photogrammetry (Score:2, Informative)
Re:Guess there's a lot of "trash." (Score:3, Informative)
Re:I think that's the marketing dept. (Score:3, Informative)
Re:Expensive (Score:3, Informative)
Four hours is not enough time to write anything of significance, and code *must* be tested, or the other people who take it to use have to do your testing and fixing for you before improving it and adding their own stuff.
Not all bugs can be found, but if you haven't even tested for basic errors then your code is awful, and unlikely to get used.
Releasing after a few days perhaps, or a week or so, once the basic code is sound, well that I've done.
Needs stereo (Score:3, Informative)
99.5% is also no good unless you don't really want to measure things accurately.
The example shown in the link shows a garage that is farther from you than the windows, and the windows are not directly in line of sight but actually off to the side a little.
I think it would really only be useful if you have a very high resolution digital camera and stand quite far from the building. But for closeup work you might as well have a ruler.
It would be useful for things you can't reach though, if you can get directly in line with it.