Home Image-Pro General Discussions

Using ImagePro to record the movement of soap film catenoid

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!


Best Answers

  • Options
    Answer ✓

    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



    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



    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

  • Options
    Answer ✓

    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


  • Options
    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).


  • Options
    @mbatchelor Thank you for your suggestions! I think all of these methods are suitable for me. I am curious about the third solution, but don't want to take up too much of your time! Maybe a summary of the method. Is this more accurate than the other solutions you have proposed? Thank you

    @YuriG Thank you!
  • Options

    sali2110 --

    Thank you for your message.

    This week is filled with obligations right now.

    If you will try to work with the LINE PROFILE TOOL and approach the challenge with that tool perhaps via the method that I suggested, we can help you here if you post your approach and result.

    Please post appropriate SAMPLE IMAGES so that we can help you.

    Good luck.

    -- Matt
Sign In or Register to comment.