Arrays of Images with Different Heights Causing Menu Blanking

[PolymerTim]

OK, I originally posted this question in the LabVIEW board before I realized it was Vision related.  I've made some progress narrowing down the cause, so I thought it would be best to start a new post here.  Here is the original post:

http://forums.ni.com/t5/LabVIEW/Blank-pop-up-menus/m-p/3281194#M958610

I'm running into an issue with all my LabVIEW menus blanking when I create arrays of images where the heights don't match.  I've attached a vi I created to illustrate the issue.  In it, I take a starting image and then extract subsets of it.  Because I don't know how many I will need to extract until run time, I'm putting the sub images into an array.  What I've discovered is that, if the heights of the sub images don't match, I get a weird glitch that causes all menus in LabVIEW to go blank.  This includes any right-click pop up in the front panel, block diagram, or project explorer and drop down selections like for enums and ring controls.  It also includes the file menus at the top of the window.

Rerunning this vi with either no sub images or equivalent height sub images corrects the blanked menus.  Also, running IMAQ Dispose (with all images boolean true) corrects the problem.

I'm fairly new to Vision, so I'm not sure if I'm missing something basic, but please let me know what you guys think.  Is there a better way to accomplish this?

Thanks,

Tim

[PolymerTim]

OK, I've made a bit more progress figuring this out and attached a new, simpler vi to demonstrate what I'm seeing.

The menublanking I'm seeing only happens when two or more images are currently displayed on the front panel within an array of image displays that have "Zoom to Fit" checked AND the image sizes are different enough to cause different zoom levels between the images in the same array.  As mentioned before, you can see the effect of menu blanking by clicking on any of the File menus or right clicking on any of the front panel indicators or block diagram terminals, etc.  When run within a loop as done in this vi, they will occasionally reappear, but not outside of a loop.  The problem persists after the program terminates.

Anything that causes there not to currently be two different zoom levels displayed in the image array indicator at the same time corrects the menu blanking such as:

-resizing the images so that they will have the same zoom level

-unchecking the zoom-to-fit option (if you can find it while the menus are blanked!)

-disposing of the images

-changing the index of the image array indicator such that there are not two or more images with different zoom levels visible

At least at this point, I can move forward with my original program by just unchecking the zoom to fit option.  But this is starting to look like a bona fide bug.  What do you guys think?

[Andrey_Dmitriev]

For me (LabVIEW 2015SP1 + Vision 2015) is not reprodicible. Blinking images in array could be an issue (but in general Vision Control in Fit mode is not good for visualization in array, because zoom ratio propagated across all elemeths), but context menus are OK - they aren't empty and properly displayed.

[tcap · Accepted solution]

Hello Tim,

Thanks for reporting this behavior. I have reported it as a bug.

I recommend using a Cluster or using the ROI Toolbar for manual zooming. If you want to use an array, each element in the array has to maintain the same zoom amount. (Similar to each LED in an array has to have the same color.)

Sorry you ran into this bug.

Regards,

[PolymerTim]

Thanks for validating the bug, tcap.  I'm not sure why Andrey isn't seeing it.  I am also running LV2015-SP1 and VDM2105.  The behavior also ocurred in LV2015 before upgrading to SP1.  There are two other users at my location on separate computers that see the same behavior.

If this could be fixed in a future version, one option might be to coerce zoom levels to the lowest zoom in the array.  At least this way you would be able to see every image.

Now that I see the problem, I can work around it.  The hard part was figuring out what caused it in the first place.