Is there a way to
Export expressions to a monochrome PNG?
I have tried the
ColorQuantize function which is mentioned in comments to this question. However, the resulting PNG image of
ColorQuantize[TraditionalForm[MyExpression], 2] is still of depth 24b. GIF file's depth appears to be 2, which is OK but it still looks like a cheat, and yes, PNG is more desired in my case. Rasterizing formulas before exporting also seems to be an unnatural hack that could and should be avoided in some way.
Export my expressions to PDF and then GhostScript them (say, via
Run) using GhostScript's pngmono device but Mathematica's current PDF Export is quite buggy. (It doesn't even print \[Bullet] correctly; TraditionalForm is lost, etc.) Printing selection to PDF and GhostScripting the result would do the thing for me… but there seems to be no way to do it ‘in a background mode’ using Mathematica commands.