editing bitmaps

[Jeffrey Mark Siskind <Qobi@ZERMATT.LCS.MIT.EDU>]

I have some image bitmaps (2D art-1b arrays) which I want
to edit (once). What is the simplest way of doing that?
Two ways I though of are using the symbolics font editor
and using MacPaint. In either case, I don't know how to
convert the bitmaps to and from the requisite editable
format. Does anybody know how to convert a bitmap to
and from a character in a font? Likewise does anybody
have code to read and write MacPaint files as art-1b
arrays?
        Thanks in advance,
        Jeff