How do I track the speed and position of cells in a time lapse sequence with Openlab?

Technical Note: 115
Reads: 6722
Creation Date: 04/05/2000
Modification Date: 12/02/2004

To manually track objects in a timelapse:

  • Open the image document that contains the images of the cells you wish to track.
  • Click on the Calibration tool icon in the image document tool bar and select the Point Count option.
  • Double click on the Point Count icon to open the Point Counter dialogue box. To track a single object per image set the "Start Point Counting at" value to 1 and the "and increment by" value to 0.
  • From the "Image" menu select "Show Measurements" and select the Point Count measurements. Hide one or more of the other measurement options, by unchecking the boxes, or by using the commands in the "Table" menu.
  • To start recording the measurements click on the red record button and the red recording light should flash.
  • From the Layers Manager palette choose the first image in the sequence to be measured. Click the Point Count tool on the centre of the cell to be tracked.
  • Move to the next image in the sequence and click the Point Count tool on the new position of the cell you are tracking. Repeat this procedure for the entire image sequence.
  • If you wish to track more than one object per image, return to the first image and 'alt' click with the Point Count tool on the image to clear all cell 1 markers. Now select the Point Count tool again, double click to initiate the Point Count dialogue box and set the point counting to start at 2 and increment by 0. Repeat as above for the second cell of interest. For more cells repeat as above increasing the value of the start number by one until all cells have been tracked.
  • At the end of the image sequence, click in the Measurements window and hold down the "apple" and "A" keys on the keyboard to highlight all of the measurements for cell 1.
  • From the "Overlay" menu in the Measurements window select "Set Point Style". in the dialogue box which appears select "Show Object Track", "Show Velocities", and "Show Direction Arrows" as required.
  • Choose a suitable color to show the cell track from the Overlay color table in the Measurements window. To make the cell track into an annotation layer go to the "Overlay" menu and select "Make Annotation Layer". This will appear at the end of the list of images in the Layers Manager palette.

To view the tracks of multiple cells it may be useful to show different cell tracks in different colors. To do this make a new annotation layer in a different color for each set of counts as described above.

To view all the cell tracks simultaneously, select the last Measurements annotation layer in the Layers Manager palette and deselect "Transparent Background" from the list of layer properties. Now select all the measurements annotation layers and from the "Layers" menu at the top of the screen select "Merge to Composite".