QImage cannot load bitmap with pixel number bigger than 16384*16384

Function 'read_dib_infoheader' in qbmphandler.cpp has a check on image size, and refuse to load it if width * height is bigger than 16384 * 16384:

 Why ? where does the magic number 16384*16384 come from ? Windows' mspaint can create or load bitmap bigger than this limit.

Here is the commit of this limit:

https://github.com/qt/qtbase/commit/621ab8ab59901cc3f9bd98be709929c9eac997a8