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I moved this to an answer so I can post pictures.

So, let's start with the first part of this problem, which is isolating the object.

You said you've tried Canny to get the edges. Did that not work? I'm getting a nice picture using your sample image there. Running findContours on it to show each separate edge as a different color gives this:

Some processing to close gaps and then some basic intelligence to limit it to inside the white areas and ignore the writing should work for just about everything.