Sometimes the automatic find logo feature gives good results, sometimes not.
I used to do it in AppleWorks, at 400% or 800% magnification. Save one picture from the movie using QuickTime Player's "Export to Picture" and import. I just drew white and black rectangles over it and finished painting individual pixels black or white with the pencil. Then save as a black & white image.

If the background of the logo is variable it can be hard to get an acceptable result.

Jan E.

The logo area must be black.