Issue with object numbers


I have a question about the objects numbers. And here is what I do:

  • I load to image sequences (timelapse) and identify objects in a combined image calculated from the respective frame of the 2 input sequences
  • then the object intensities in both frames are measured and the ratio is calulated

The question I have, is the following. When I display the detected objects with the object numbers as an overlay, the number for a certain object changes sometimes from frame to frame. But my purpose is to track the ratio of a ceratin object over time and when in sort the resulting excel sheet afterwards for object xy (to plot it), this may not be the identical cell for all frames, since in most of the frames the object number for this idividal cell(as an example) is 20, but once a while it might be 19 or 21?

I attached the pipeline and a movie of the detected ROIs with the object numbers to make my point more clear.

Thanks for your help,


Ratio340_380_TILL_display.cp (8.46 KB)

Have you seen the TrackObjects module? It seems to do what you want.

Hi Sebi,

Timsmith is correct; TrackObjects is the module you probably want.

The reason the ObjectNumbers do not match frame to frame is that in normal circumstances, each frame is treated independently from any other. When objects are detected, the ObjectNumber is determined solely by (x,y) location in order of increasing coordinates. When using TrackObjects, a unique label is also assigned to objects which persists from frame to frame; the label is created when the object appears and stops when the object disappears.


After running the TrackObjects Module on my time lapse images, I see both objectNumber and TrackObjects_Label vary with corresponding coordinates across the images.

Is there anything I may be missing to keep the tracking of each object in the images consistent?