Finding plug contact angle using image processing

I came across lot of codes available for finding contact angle of pendant drops. Can anyone please guide me to find contact angle for the configuration shown below? http://s8.postimage.org/wsvetl75x/Edge1.png

Thanks in advance

Answer 1

[Image Analyst]

I have no idea what I'm looking at, and have no idea what is supposed to be measured in that image. What is a pendant? Something that hangs around something, like your neck? What is a plug? The blades at the end of a power cable that you plug into the wall? How would these be related to contact angle, like the angle a droplet of liquid has when it meets a surface?

[Vyas]

@Image analyst, Sir, thanks for responding. This image shows a pendant drop: http://www.google.co.in/imgres?imgurl=http://www.ramehart.com/newsletters/pendant_drop.jpg&imgrefurl=http://www.ramehart.com/newsletters/2010-06_news.htm&h=308&w=400&sz=38&tbnid=y873cDrHclJ1KM:&tbnh=86&tbnw=112&zoom=1&usg=__FJP-dwP8BUJEM3e24yooj9sMO2c=&docid=C8nnuSY869EgnM&sa=X&ei=368KUYSqFMWzrAeO4YCIAg&ved=0CDYQ9QEwAQ&dur=3266

Yes sir, As you told, Contact angle is measured by tangent drawn from the point of contact of liquid on surface and the horizontal. The image I attached is a liquid inside a horizontal tube after edge detection. I am herewith sending the image again indicating what exactly I am trying to find out using MATLAB. Kindly take a look : http://s7.postimage.org/6xpbz2323/Edge1.png

Thanks S.Vyas

[Vyas]

And a volume of liquid inside a small diameter tube is usually called as liquid plug.

[Image Analyst]

Is that the best image you can get? It looks like it was binarized with an ineffective algorithm.

[Vyas]

Sir, the original image without any edge detection is here: http://s4.postimage.org/sv4c11qod/20ul_adv2_C001_H001_S0001000003.png The image in previous comment is after few trials of edge detection that I tried in ImageJ software. Kindly help me in finding the angle in this situation.

[Image Analyst]

What I would try is to use imfindcircle() to find the circle part. Then find the intersection lines. Then knowing the equation of the circle, you can get the tangent to it where it intersects the top and bottom lines.

[Vyas]

Sir, Thanks for your help, I am trying on and it seems to come good. Shall seek your help again if needed. Thanks :)