Extract contact angles from videos with this tool. ContactAngle help you extract contact angles from videos of liquid droplets on a surface.
The program takes a very simple approach like the following:
1. Read a frame from the video
2. Binary threshold (convert it to black and white)
3. Detect the shape of the droplet in an area close to where it touches the surface
4. Fit a parabola for each side and take the contact angle as the slope of the function at the point where it touches the surface.
5. Repeat for all frames in movie.
6. This simple approach is robust and fast, but may not be as precise as other algorithms that user a larger part of the image. However, it is accurate enough for most purposes.

The license of this software is Free, you can free download and free use this video utility software.