How to measure the size of objects with a very high accuracy

Is it possible to measure the size of objects and achieve an accuracy of 1 mm or more with measurement through a computer vision camera? The answer is yes. We will see some cameras used to measure the size of objects and do some tests to answer this question.

What can object size measurement be used for?

Computer vision object measurement techniques are used when it is necessary to derive measurements from the camera. For example, in manufacturing the measurement of objects that then need to be placed in the warehouse, check the conformity of a production, or organize a shipment.
This procedure is also very important when you have to measure an object in the conveyor belt and the required margin of error is less than 1 mm.

What kind of hardware is required for measuring objects?

Not all cameras are suitable for this purpose, and a distinction must be made between cameras for industrial use and others; even just the lens distortion or data rate can make a difference in higher or lower production speed. Let’s see some examples:

Intel realsense d450i

The most popular and well-known camera for measuring the size of objects is intel realsense d450i , and it is stereovision and infrared which allows measurement. To use it you can see the details on the installation Identify and Measure precisely Objects distance

measure the size of objects with Intel realsense d450i

lntel RealSense LiDAR Camera L515s

Also, lntel RealSense LiDAR Camera L515s camera is used to measure distance but uses LIDAR technology

measure the size of objects with lntel RealSense LiDAR Camera L515s

Opencv Ai kit

Another popular camera for measurement is Install OpenCV AI Kit (OAK) On Windows which allows measuring the size of objects with a stereovision video camera

Opencv Ai kit


All of the previous cameras are readily available commercially but are not suitable for industrial use, one of the reasons is the connection, they have only one USB port. This is a disadvantage because you can’t use cables longer than 3 meters, and the speed will not be up to the required performance.

industrial camera for measure the size of object

You can see the camera specifications MER2-507-23GC-P . would like to make it clear that you should not purchase this camera until you have verified the needs of your project. Another aspect to consider is the lens; for this purpose, it is essential to have a distortion-free lens.

Measure the size of objects test

To do this demonstration I wrote a small prototype to retrieve the frames from the cameras and take the measurements from the screen.
With this single camera, it is possible to measure only one measurement, and we will not have all the measurements of the whole object because it is more complex and requires more advanced devices

example of mesurmente with industrial camera

Is it possible to automate recognition with AI?

The purpose of the video is to show you the accuracy of measuring objects with an industrial camera. Clearly for more advanced use and in real conditions you need to add AI development to your software.

To learn more about object recognition you can take a look at the course Object Detection (With Opencv & Deep Learning)


Learn to build Computer Vision Software easily and efficiently.

This is a FREE Workshop where I'm going to break down the 4 steps that are necessary to build software to detect and track any object.

Sign UP for FREE