Vision height measurement of object

[Cres2608]

Hi, my project consist of a stationary camera placed near the ceiling. The task now is to enable the user to input a height, then the program will only track objects with said height. So far I have managed to create a program that tracks a single moving object using subtraction and centroid blocks in LabVIEW but I'm stuck with the height measurement. Most online sources say it is impossible to do so with just a camera since we do not know the distance between camera and object. Is this true? Or is there a way to do it on LabVIEW? I can upload my VI here if anyone requests.

[WinterIsHere!!!]

Hey, 

When it comes to using a camera to do measurements which are not just in a 2D plane and you need to do all the math required and cannot rely on the camera to do it for you. I wouldnt say its impossible for you to do this but you defintely need to find a way to do all the math. The math will get harder because you are looking for 3D measurements in a 2D image in pixels. I suggest you to reconsider your hardware configuration and positioning. This is very important and may reduce a lot of math to do. can you share with me what is your current hardware setup like? Any pics and/or diagrams are appreciated.

Thanks.

[Hatef.fouladi]

there are some method to do this but the resolution of your distance measurement is issue that you have to concern about it

[Hatef.fouladi · Accepted solution]

see some these method in these links
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.413.907&rep=rep1&type=pdf

http://mint.fh-hagenberg.at/wp-content/uploads/2014/07/icdcsw2012_holzmann.pdf

https://zone.biblio.laurentian.ca/bitstream/10219/2458/1/Peyman%20Alizadeh%20MSc.%20Thesis%20Correct...

https://www.computer.org/csdl/proceedings/icdcsw/2012/4686/00/4686a088.pdf