How can I take Label number fixed？

There are three objects in the binary image. Now,I have already labeled the objects in Simulink. At the top right corner of each object is the number of this object,1 or 2 or 3.The number of object will be changed when they are moving. But I want to keep the number of each object until they are disappeared, no matter how they are moving. For example, object A is labeled by No.1 at first, no matter how it is moving ,until it is disappeared,it will always be labeled the number 1. So can you tell me how can I keep the number of label , no matter how they are moving. Thank you very much!

Answer 1

[Walter Roberson]

This is not always possible. If the objects are sufficiently similar in shape, then if they overlap enough at some point, it may not be possible to determine whether they passed through (or behind) each other, or if they instead collided and rebounded.

[Yt li]

Thank You for your answer. I think that they are sufficiently similar in shape but not overlap enough at some point . Can you tell me how can I keep the number of each object?

[Walter Roberson]

If they have unique characteristics, then you can use those to relabel. If they do not then you will need to do velocity tracking to figure out which blob is which and use that to relabel. I do not have any experience with velocity tracking myself.

Answer 2

[Image Analyst]

Search MATLAB Central for "tracking" - there are many pages on object tracking.