How to detect zig-zag lines in a image

In an image, I have some zig-zag lines (similar to square wave and triangle wave, but frequency and amplitude varies on each of them) and I need to detect them out. What will be the algorithm to do it? Any existing code sample?

[Image Analyst]

You forgot to tell us where you uploaded your image to. The answer depends on what the image looks like.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

Answer 1

[Image Analyst]

You might look at the code I gave here: http://www.mathworks.com/matlabcentral/answers/40052-detect-a-sinusoid-in-an-image