Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Would it be sufficient to just remove single white pixels or whatever is the minimum area of white? If so, you can do that with -connected-components. Filling in would likely result in thickening your characters where you do not want them thicker or filling in closed parts of the characters.