Ah yes, I have this Image Analyzer software too.. You are right, they call it 'Out of focus blur'.. But the effect is known in the photographic world as 'Tilt-Shift'.
But, as you have discovered yourself, it's quite easy to create this effect in Xara Designer, Xara Web Designer and Xara Photo & Graphic Designer.
I agree - it's a neat effect and with the right photo it works very well.