Well you do have something for reference, hence the use of the card. Saying that after watching the a video for the app I can't seem it seems too user friendly.
So you either need a reference of an object that has some known size, or you need to deduct the size from the image. One idea I just had that might help you do it is what the iPhone's 4 flash (I'm sure it's very complicated by it might just work for some stuff).
Here's what I think.
When the user wants to measure something, he takes a picture of it, but you're actually taking two separate images, one with flash on, one with flash off. Then you can analyze the lighting differences in the image and the flash reflection to determine the scale of the image. This will only work for close and not too shining objects I guess.
But that's about the only other way I thought about deducting scale from an image without any fixed objects.
Answer from Ron Srebro on Stack OverflowWell you do have something for reference, hence the use of the card. Saying that after watching the a video for the app I can't seem it seems too user friendly.
So you either need a reference of an object that has some known size, or you need to deduct the size from the image. One idea I just had that might help you do it is what the iPhone's 4 flash (I'm sure it's very complicated by it might just work for some stuff).
Here's what I think.
When the user wants to measure something, he takes a picture of it, but you're actually taking two separate images, one with flash on, one with flash off. Then you can analyze the lighting differences in the image and the flash reflection to determine the scale of the image. This will only work for close and not too shining objects I guess.
But that's about the only other way I thought about deducting scale from an image without any fixed objects.
I like Ron Srebro's idea and have thought about something similar -- please share if you get it to work!
An alternative approach would be to use the auto-focus feature of the camera. Point-and-shoot camera's often have a laser range finder that they use to auto-focus. iPhone doesn't have this and the f-stop is fixed. However, users can change the focus by tapping the camera screen. The phone can also switch between regular and macro focus.
If the API exposes the current focus settings, maybe there's a way to use this to determine range?
I just learned that I can measure with my iPhone
optics - Calculate the distance between two points from iPhone Camera - Physics Stack Exchange
measurement - Measuring a room with an iPhone - Stack Overflow
make measurements from a photo
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For some reason I am completely blanking on the best way to do this: I need to determine if I can consistently throw a frisbee measure 200ft. But I can figure out how to measure exactly (or near to exactly) 200ft. I don’t know if I need a special app or if it’s something the iPhone can do with a native app (Maps? Health? Measure?). If anyone can point me in the right direction I would be immensely appreciative, I know the answer is obvious but I can’t think of it.
I discovered something the other day that I wanted to share. I have the iPhone 12. In my utilities folder there is an app called Measure. You point your phone at something, say the end of a wall. A dot with a circle around it pops up. Place that dot where you want to start your measurement, hit the plus button and then just walk to the other end of the wall, hit plus again, and it will measure that distance. Sometimes I can see the measurement displayed on the screen before I finish, sometimes I can't. Not sure how that works. But when you hit the plus sign the second time the measurement goes into a list.
You access that list by pressing on the upper left side of the screen on the three dot/lines. The beauty of this is that you can measure the entire exterior of a home by doing this. Every time you take a measurement it goes into that list, in order.
I've used this now on two inspections. First I take all my measurements. Start at one corner of the house, hit plus to start, walk down the length of the wall, hit plus to finish. I continue this with every wall that I need measured. As I am doing this, I do not have to write anything down. It's all being stored on this list, in order. After I've arrived back at my starting point. I make another "trip" around the exterior and draw a sketch of the exterior of the home. I then make a third trip around the house to take my pictures.
At this point I can go inside, or back to my truck if I don't want the homeowner/realtor bothering me, and I can put the wall measurements from my list on my drawing. When you access this list you will see, at the bottom of the screen, a button that says copy. I suggest hitting that button. It will copy the entire list. I made a folder in my notes app called appraisal measurements. I paste the list into this folder. That way you won't lose your list before you have a chance to put the measurements on your sketch.
I finished measuring a house yesterday and when I came inside the Realtor, who had been watching me, asked "are you measuring with your phone?" So I showed her how to do this. She was so glad to learn this. She said she has been looking for an measuring app and this was already on her phone. At this point I had not recorded my measurements and when I went into my list, they were gone. Had to do it again. So save your list.
I checked the accuracy with a tape measure and its very accurate. Another nice feature is that you don't have to be right next to the wall to take the measurement. So you don't have to squeeze behind that bush, that's full of morning dew, and get your shirt soaked. Let me know what you think. Try it out. I think it's a game changer for me, especially with the new ANSI standards.
You could stand in one corner and throw the phone against the far corner. The phone could begin measurement at a certain point of acceleration and end measurement at deceleration
1) Set iPhone down on the floor starting at one wall with base against the wall.
2) Mark line where iPhone ends at top.
3) Pick iPhone up and move base to where the line is you just drew.
4) Repeat steps 1->3 until you reach the other wall.
5) Multiply number of lines it took to reach other wall by length of iPhone to reach final measurement.
=)
when taking photos in portrait, the depth camera is used.
so, is there a way to make some measurements of some objects from the photo?
if yes, then how?
thanks in advance for the help
best regards
I know there’s a meter app that uses the camera, but I’m looking for one that works more or less like this: you put an x object on a table, put a coin or whatever object y near it and then you take a pic. You tell the app the measure of the object y and then ask to calculate the measure of object x based on the measures you gave.
Is there anything like this ? What is it called ?
Thanks in advance.