what happens if we have two images from two expressions and they arrive at the wrong order (second image is faster than the first one)?
All will worked, because each expressions have own m_tempFile.
Are QTextStream and QChar really required in this file?
QTextStream no needed, but QChar used in recordSep, unitSep. Though, maybe i could change it to char.
use c++11 range based loop instead of the foreach macro.
is this int variable still required in the new code?
You right, the variable not needed, I just had forggoten to remove it.