Using ImagePro to record the movement of soap film catenoid

sali2110

Hi there,

I am a new user of ImagePro, and my goal is to quantify the movement of soap film under an electric field. In particular, I am looking at the profile of a soap film catenoid suspended between two rings.

The radii of curvature on both sides of the membrane profile fluctuates, and there are too many frames in my videos to go through manually and measure the maximum distances between membrane and outer boundary at the mid-plane.

This is a sample from one video. There is a rod in the middle (this was my electrode to create the electric field), but that is not involved in the video analysis. I want to determine how much the radius of curvature is changing on the left compared to on the right.

What is the most efficient way I can accomplish this? Could I automate this somehow?

Please let me know if you need more information!

Thanks.

YuriG

Hi sali2110,

You can measure that using the Line profile tool: Create a horizontal line profile and add "Valley" edge detectors (if the boundary is a dark line, as on your picture), which will detect film boundaries, then just get positions of these markers (measurement: Origin - Valley) going through the time sequence. You can collect all these measurements automatically clicking the Collect button (with "All Frames" activated).

Regards,

Yuri

mbatchelor

2022-05-31-111714

sali2110 --

The LINE PROFILE TOOL that YURI directed you to is a powerful TOOL that may be exactly what you are looking for.

Two other ways to get to the information you are looking for are illustrated below.

The first one used the

    BEST FIT ARC TOOL

   

to clean up the the SOAP BOUNDARY and then did a COUNT on an ROI that would find the VOID outside the SOAP.

The second used the

    PITCH LINE TOOL

   

To create a list of MEASUREMENTS that are the LENGTHS of the LINE SEGMENTS from the REFERENCE LINE to the SOAP BOUNDARY.

I believe that the FIRST METHOD shown below could be automated and that the BOUNDARY POINTS along the SOAP BOUNDARY could be extracted and used to calculate the RADIUS OF CURVATURE of the SOAP BUBBLE.

I hope this information is helpful.

-- Matt

mbatchelor

2022-06-14-194839

sali2110 --

The LINE PROFILE TOOL recommended by YURI is a good solution to your challenge.

Below, please find a SCREEN CAPTURE that illustrates how the LINE PROFILE TOOL can be used to measure the SOAP FILM WIDTH at three locations. 

The SOAP FILM needs to be analyzed LEFT SIDE and RIGHT SIDE, then you can use the V1 to V2 DISTANCES as the LEFT SIDE MEASUREMENTS and the V3 to V4 DISTANCES as the RIGHT SIDE MEASUREMENTS.

The solution that I proposed may have some benefits and a third solution suggested by a recent webinar I attended may also fit your challenge.  Documenting that third solution would take significant time that I will do if you are interested.

Please let us know your thoughts on this.

I hope this information has been helpful.

-- Matt