Position the Marker
- 
                Select a marker from the list or from the graphics window, verify the lock
                    option is unchecked, then choose from the following options.
                
- Pixel Collector
 - Indicates that left mouse clicks on the screen will set the location of the currently selected marker in the list.
 - X and Y
 - The X and Y positions of the marker with respect to the original image size.
 - Initial Frame Index
 - The initial time frame to start the tracing of the marker. This frame index is where the marker was created. You can generate markers at any time frame.
 - Final Frame Index
 - The frame number where you want to stop tracing the selected marker. The default value is -1, which means it is using all of the frames except the last frame. If you want to shorten the curve, enter a positive frame index.
 
 - Click Apply.