Vision toolkit redraws IMAQ image displays on CLOSED front panels

[Root_Canal]

Normally when calling a subvi whose front panel is not open, Labview doesn't waste time "redrawing" front panel objects for that subvi. If calling a subvi whose front panel contains an IMAQ image display, Labview wastes the same amount of time "redrawing" the image display of a closed (not visible) front panel as it does when the image is actually being displayed on an open (visible) front panel.

It's really convienient to be able to use front panel objects to quickly test subvi output. I assume that's the reason why you don't redraw regular controls and indicators on closed front panels. The same convention should hold for Labview Vision; perhaps especially for Vision, since there is a high performance penalty for rendering updates to an image display, and it is extremely convienient to be able to see what a subvi is doing to an image.

I notice several messages from experienced LabVIEW programmers that remind LabVIEW users to close unnecessary subVI front panels in order to increase execution speed as this supposedly prevents LabVIEW from redrawing those front panels. This makes me believe that others will assume that the IMAQ image display indicators and controls function in much the same way as other LabVIEW indicators and controls in this regard, and will also be extremely put off when they finally figure out what is eating the CPU cycles in their application.

Therefore, I think this deserves a CAR.

Thanks,
-root

Message Edited by Root Canal on 05-18-2009 04:35 PM

[CWolf]

Root,

Thanks for pointing this out.  I would suggest that you submit that as a product suggestion.  I will also submit it internally.  That way R&D gets the feedback two different ways.  

-Christina