Aivia Software

Filament Tracking

The Filament Tracking recipe in Aivia detects the leading edges (or "heads") of thin filaments and tracks their motility over time in fluorescence time-lapse microscopy images.

This recipe is well-suited for the detection and analysis of thin filaments in gliding assays.

Parameters and Presets

Parameters

Recipe parameters for Filament Tracking and their descriptions are summarized in the table below.

Preset Group

Parameter Name

Min Value

Max Value

Description

Preset Group

Parameter Name

Min Value

Max Value

Description

Detection

Background Removal Factor

1

100

Adjusts the sensitivity of the background removal operation; a lower value will preserve larger objects and more background variations

Contrast Threshold

0

255

Adjusts the detection sensitivity on the background-removed image; a lower value will detect more objects

Frame Offset

1

1,000

Specifies the time offset (in frames) the detection will look at to determine whether a filament endpoint represents the leading edge ("head") or the trailing edge ("tail") by the change in intensity; a higher value will improve the detection of slow-moving filaments

Min Head Separation Distance

1

100

Specifies the minimum distance between two filament heads

Tracking

Max Search Range

0

1,000 px or µm

Specifies the maximum distance for track-point matchmaking between successive time frames; a higher value will expand the search distance for fast-moving objects

Min Track Length

0

10

Specifies the minimum number of time frames before a detected object is considered a valid track; a lower value will generate more, and often shorter, tracks

Gap Length

0

10

Specifies the maximum number of time frames for linking tracks that are spatially colocated; a higher value will preserve particle tracks for longer

 

Presets

There are two preset groups in the recipe: Detection and Tracking. Each group has three pre-configured parameter groupings to help you get started on the analysis. The default preset values are in the sections to follow.

 

Detection

Parameter Name

Low

Medium

High

Background Removal Factor

25

55

75

Contrast Threshold

24

16

13

Frame Offset

100

20

1

Min Head Separation Distance

15

5

1



 

Tracking

Parameter Name

Low

Medium

High

Max Search Range

10 px or µm

15 px or µm

30 px or µm

Min Track Length

5

5

5

Gap Length

5

5

5



 

Tutorial

Before beginning the tutorial, please download the Filament Tracking Demo image. For information on how to select presets or modify parameter values, please refer to the tutorial on how to use the Recipe Console.

  1. Unzip the demo file and load the demo image, “FilamentTrackDemo.tif,” into Aivia.

  2. In the Recipe Console, click on the Recipe selection dropdown menu and select the Filament Tracking recipe.

  3. Select the Medium preset for the Detection group and the Tracking group.

  4. Click on the caret to the left of the Detection preset group to show the preset parameters.

  5. Modify the parameter value as follows, leaving the other parameters intact:

    • Contrast Threshold: 50

  6. Click the Start button or press the F4 key on your keyboard to begin applying the recipe to the image.

The detected filament head tracks will be overlaid on the image.

 

Results

 

Filament Tracking tutorial results

 

Measurements

The Filament Tracking recipe generates morphology and position measurements for each detected object. You can add additional measurements to the analysis results with the Measurement Tool in Aivia and view measurement definitions on the Measurement Definitions page. The measurements generated by the recipe are given in the table below.

Morphology

Position

Advanced

Morphology

Position

Advanced

  • Path Length

  • Total Frames

  • First Frame

  • Last Frame

  • Mean Square Displacement

  • Velocity Magnitude

  • Average Velocity Magnitude