Same-Size Images Not Possible with Different Resolutions



I am writing medical-imaging software and want to connect two 19-inch monitors
with different resolutions.

I have assumed that if one monitor has twice the resolution as the other, the
object will be half the size on the higher-resolution monitor. Is there is a
way, within the Macintosh OS or via a third-party utility, to have an object
display the same size on both screens despite twice the resolution on one
monitor?

The QuickDraw graphics model does not provide a mechanism that allows for
display systems (card and monitor) with different dots per inch (dpi)
resolutions to display an image at the same size. QuickDraw assumes a display
system has a resolution of 72 dpi. This means that a 2-inch square (144 by 144
dpi) on a Macintosh Plus screen (72 dpi) will be an 2.09-inch square on the
AppleColor High-Resolution RGB Monitor (69 dpi).


Published Date: Feb 18, 2012