Imaq windraw vs. Imaq image display

Until recently, i've been using the imaq windraw vi to display the real time images i capture. Now I am trying to use the imaq image display vi instead...the only problem is that it slows my application way down. Does anyone know why it would slow the application down so much? With windraw i processed about 900 images a minute, but with the image display i only process half that many. Does it have something to do with the image display being part of the GUI??

Most likely the slow down does have to do with the image being displayed as part of the GUI. There are some things that you can do to increase performance. Take a look at this KB for some good suggestions.

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Thresholded image in "Image Display"

Hi:
I'm using LabView 7.0 and IMAQ 7.0. In IMAQ there is a control called "Image Display". I want to display a thresholded image in the "Image Display" but I only get a dark frame.
In the "Imaq WinDraw" this is posible and I tried wire the Image Out of "Imaq WinDraw" to the "Image Display" but it does not work.
Can you help me or send me an example?
Thanks!!

Try changing the palette on the Image Display to Binary. It should work fine.
Bruce
Bruce Ammons
Ammons Engineering

Why does moving the mouse over an IMAQ image display slow the GUI down so much?

I have a large application with several vi's running simultaneously under labview 8.6.1. When I mouse over an image display control in one of the vi's, everything slows down a shocking amount in all the other vi's. The windows task manager does not show a large increase in CPU use. My pc is has a quad cpu with 4GB of RAM, and the CPU and memory loads do not appear to be terribly taxing to the system. However, many of my vi's apparently come almost to a standstill if I just move the mouse in a circle around my image control.
This looks like it is largely a GUI display issue. If I make a new vi and put a while loop in it that only displays the iteration loop number to an indicator, I can see the iterating occurring, then stopping totally when I mouse inside the image display control. When I stop moving the mouse inside the control, or when I move it outside the control, the interation loop number jumps up, as if it had been incrementing behind the scenes the whole time. So only display of the interating was halted.
This problem occurs even if the vi with the image control is not executing. If the vi with the image control is open but not running, and I mouse over the image on it, the other guis all come to a screeching halt.
Does mousing in the image display control really utterly crush all other guis in all other labview windows? Is this an issue inherent to the image display control? If so, is there anything I can do about this?
Also, this issue is not entirely limited to display. I started looking at it in greater detail because this issue also exposed what I think is a race condition in my code. I have a vi that acquires an image from a ccd and puts it into an IMAQ image.ctl. This image then gets passed up to a vi up the call chain, and is put on a queue and sent over to be de-queued by a vi that has the image display control. Here's the kicker: when I mouse over the image display control, the image successfully gets acquired inside the subvi, and if I probe the wire leading to the output IMAQ image display.ctl, I see the image. If I simultaneously probe the wire coming out of the subvi one level up the call chain, the image gets lost about half the time. This only happens if I am mousing in the image display control IN A TOTALLY DIFFERENT AND SEPARATE VI. If I bump up the priority of the ccd image acquisition vi to 'highest priority', the problem only happens about 1% of the time, and I really have to mouse around to make it happen. Still, it's disturbing that mousing in the GUI in one window results in a failure of a separate subvi to simply pass an image up the call chain. I understand that IMAQ images are referenced rather than passed by value, but I don't see why there should be a failure to pass the image up the call chain. I've looked for a race condition, but can't find one.
Eric

I have finally been able to replicate the behavior that you are seeing on another computer once the image was large enough. Here are a few notes about this behavior:
First. The UI only slows down when the images are large, 16 bit images. The reason why this is unique to 16 bit images is that they can only be displayed on the front panel as 8 bit images. The workaround that Weiyuan suggested to change the 16 bit display mapping hints towards the root of the problem...that any time a mouse runs over the indicator, Windows asks the entire image to re-draw (having a separate indicator overlapping the image will create the same behavior). With a 16 bit image, not only does the image have to re-draw on the screen but the 16 bit pixels need to be mapped to 8 bits. When setting the 16 bit display mapping to Full Dynamic, this requires mor computation/pixel than 90% dynamic or one of the other mapping schemes.
This is expected behavior if your program is running and you're trying to display a large 16 bit image. To fix this behavior there are a couple options:
Change the 16 bit display mapping to something other than full dynamic. You can choose which 8 bits to display or if you want to map the bits.
Resize the image just for viewing purposes on your front panel (since you aren't going to view every single pixel of you image on the screen). You can use the IMAQ Resample.vi to do this. This will allow you to take your 1500x1500 pixel image and only display a 500x500 pixel version.
If you are interested in viewing small details of the large image, consider just displaying a smaller region of interest at a time.
Let me know if any of these solutions work for you. Good luck on your application.
Zach C.
Field Engineer
Greater Los Angeles

Flickering problem with live viewing with IMAQ Image Display

Hi everyone,
I am trying to write a program to do live imaging with Andor camera. I am using some examples from Andor. The images are acquired in sequence and send into IMAQ Image Display and also Intensity Graph. There is minimal flickering issue in the Intensity Graph but there is very bad flickering problem in IMAQ Image Display. Perhaps I misunderstand how to optimize the vision tools. Does anyone know how to overcome this issue? I have attached the code that I am testing. Thanks in advance.
Best regards,
Han Yen
Solved!
Go to Solution.
Attachments:
iXonRTA_live_0.0.1.vi ‏70 KB

You can use Vision Assistant to test our vision functions. Vision Assistant is really meant to prototype - it does not have all teh functionality of Vision Development Module and is not as flexible as we don't allow you access to all the settings for every function.
I recommend starting in Vision Assistant and then porting over to LabVIEW or C (whatever you are most comfortable with)...this is built-in functionality. There is nothing wrong with using Vision Assistant to do live imaging, just that you run into limitations and you will only be able to use this code on computers that have Vision Assistant.
Hope this helps.
--Michelle
Instrument Control R&D
National Instruments
Instrument Control
Machine Vision

Can't find image display in the IMAQ Vision control palette

Hi
I am trying to display an image on the front panel. But i cannot find the image display vi .. according to the manual, it is available from the IMAQ Vision control palette. I have the academic version of LabVIEW 7 express. Does my version have the vi? Thank you
rsa..

Hello,
The IMAQ Display control is a part of the NI-IMAQ driver. This driver is free of charge and can be downloaded from our website by going to www.ni.com/download. Here is a URL directly to the current version of IMAQ: "http://digital.ni.com/softlib.nsf/websearch/CD7EAFE90E9E47398625703000754A12?opendocument&node=132060_US". If you plan on using that control, I would recommend just installing the driver for it on whatever computer you want to use it on.
Regards,
Aaron B.
National Instruments

Using IMAQ Image Display control vs IMAQ WindDraw for large image files

Hello All;
I am designing an application that is currently using IMAQ Image Display control to view large images (5K x 3K and larger). My problem is that these images take 10-20 seconds to load and display, whereas if I use IMAQ WindDraw to display my image in a separate window, it only takes a couple of seconds. My application is designed such that I am making use of the Subpanels in LabVIEW 8.0, and to make it pleasant for the user, the interface is such that my line profile, histograph and image viewer displays are contained within the same GUI (panel).
I read the National Instruments application note regarding displaying of large images, and it did not seem to make a difference. For example, I switched the 'modern' IMAQ Image Display control with the classic Image Display control, since the 'classic' does not contain any of the 3D rendering tools which might slow the process down.
Why is there such a huge difference in loading times if I am trying to do exactly the same thing with both methods? How can I bring the IMAQ Image Display control up to the same speed as the IMAQ WindDraw tool?
I am currently using LabVIEW 8.0 with the latest IMAQ/NI Vision package from NI (IMAQ v7.1?). Thanks.
DJH

Use a property node and select 16 bit image mapping. You can create a control for this or whatever you need. If you select the individual elements, you can get enumerated controls.
Bruce
Bruce Ammons
Ammons Engineering

Using IMAQ create, set-up, acquire and windraw to save image without color map

Hi,
Attached is my VI (using labview 8.5) and am not sure where it is getting the color info from, but it saves the image as jpeg/bmp/tiff with colormap (confirmed by imread in matlab). Can someone help me save these images without colormap info.
Thanks
Attachments:
HL Grab with two boards and SONY XC55_Images.vi ‏166 KB

Hi Maverick269,
I noticed that you posted this question over on the Machine Vision forums as well. That will definitely be a better place to get this question answered, so let's work on the issue over there :
http://forums.ni.com/t5/Machine-Vision/Using-IMAQ-create-set-up-acquire-and-windraw-to-save-image/m-...
In the future it helps us stay organized if we limit each issue to a single thread.
Cheers,
Andy C.
Applications Engineer
National Instruments

Show the line after draw with IMAQ selectline.vi in the image display

hi..
may i know how to show the line on the image display after i draw the line by using the IMAQ select line.vi??
i use the the IMAQ select line.vi for drawing few couples of lines...but i don know how to show it all on the image display...
because i will forget the location of the lines after i draw it by IMAQ select line.vi...
thanks for help..

Hey,
Just use IMAQ Draw.vi
Christian

IMAQ WindDisplayMapping...for Vision Image Display Control?

The IMAQ WindDisplayMapping operates on an IMAQ window display. Is there an equivalent fx that will operate on the Vision Image Display Indicator that can be placed on LabVIEW front panel? (Or do I need to code up the equivalent fx?)
Thanks,
Don

Use a property node and select 16 bit image mapping. You can create a control for this or whatever you need. If you select the individual elements, you can get enumerated controls.
Bruce
Bruce Ammons
Ammons Engineering

How do you change the location of a small image within an IMAQ image display?

I have an image that exactly fills the display. But then I want to extract a portion of the image and display that small piece, but have it be in the same location as it was before, not centered in the display (essentially I want to crop the image but leave it in the same location). I tried the 'Image Center Position' property node for the image display, but is resets itself to the center of the display. Can anyone offer any suggestions?
Thanks,
Marty
Attachments:
Crop_Pic_Test.vi ‏102 KB

Marty_M wrote:
I have an image that exactly fills the display. But then I want to extract a portion of the image and display that small piece, but have it be in the same location as it was before, not centered in the display (essentially I want to crop the image but leave it in the same location). I tried the 'Image Center Position' property node for the image display, but is resets itself to the center of the display. Can anyone offer any suggestions?
You misused the Image Center position property : it works only on images larger than the display area. Have a look at the simplified version of your sample vi.
One way to achieve your objective will be to create a black (or white) background image, with the same size as the original image and to paste the small piece over this BG.
Happy New Wires
CC
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...
Attachments:
Crop_Pic_Test[2].zip ‏22 KB

Imaq Image Display Control - Zoom tool - zoom factor changes slowly

Hi at all,
we have a strange behavior with the zoom factor of the Image Display Control in an Labview executable.
Ususally by clicking into the image with the zoom tool activated, the zoom factor changes from 1,2,4,8,16, ... ("x2")
Now we have one PC, where it changes from 1,2,3,4,5,... ("+1")
Has anyone an idea on which windows setting this behavior depends on? The PC runs with Windows XP SP3, the LV-Exe was built
with LabVIEW 8.5.1 and the Vision Development Module 8.5.0. Is there any regsitry setting where I can adjust the "click intensity" or
something like that? Or can I set a property of the image control to force a specific behavior?
Actually I have never seen this behavior before, I only know the half/double mode.
In the software the operator has to search for fiducials on PCBs what means he has to click several times into the image.
Changing in the Mode "+1" instead of "x2" is not acceptable for him.
Thanks for your help!
Stefan

Hello Stefan,
thank you for posting at the National Instruments forum. The "Zoom Behaviour" was changed due to customer requests. I totally agree with you, that it is not the best solution to click 24-times to get the desired region of interest.
I created a small example for LabVIEW 2010, which uses a property node and event structure, to perform the zoom programmatically.
Best regards
MarianO
Attachments:
Calculate Zoomfactor.vi ‏21 KB
Image Example.vi ‏63 KB

Problem using IMAQ Array to Color Image vi

I am doing some pixel manipulation & while going from an image to an Image Pixels (U64) array using IMAQ Color Image to Array VI I cannot see the image once it is modified.
I am...
1) converting the image to the 64 bit pixel data using IMAQ ColorImage to Array.vi
2) doing the manipulation
3) converting back to an image using the IMAQ Array to ColorImage.vi using the 64 bit input.
What I get is...
1) a black image with data behind it... meaning... if I take the magnifier tool and go to the approximate locations of my image where I expect to find the manipulated data, it is there.
2) cast that image to a 32 bit image & still get a black image for the output. The data however is no longer there and appears to have been stripped.
3) no error's out of any VI's...
TIA

With Vision 2009 situation is not better.
It happened because U64 image displayed in full scale. So, if you have full range of intensities (from 0 to 65535), then you can see something. But if your intensities in small range, for example, 0...255 in all channels, then you will see black image.
Feel differences:
It should be possible to map U16 values into U8 display range with given range (like IMAQ WindDisplay Mapping does), but right now this feature available for I16 images only, not for U64. What you can do is following - map each channel to U8 (with linear LUT, for example), put channels together, then display 32 bit RGB instead of U64.
Andrey.

IMAQ Overlays slow down Image Acquisition

Hi,
I am acquiring 1280 x 720 images at 12 frames per second and displaying the feed on an imaq image display control which works just fine but when i overlay a large amount of points onto this live image, for example 3000 points, using the copy overlay function, my cpu load goes way up and my frames per second drop way down. Is there something i can do to avoid/minimize this performance drag that i am seeing?
Thanks

I am displaying every image, it is a live video feed and i need to overlay several grids with up to 3000 points in each grid onto the image. Im not sure you can have multiple ROIs displayed at once can you?
Below Is an example of what i need to achieve and if i can do this with ROIs then that would be ideal?
Attachments:
test2.png ‏1671 KB

Imaq mask on U16 image

Hello!
Can someone please explain to me the following:
I can use IMAQ mask on every image type except for the U16. Why is that?
Please see the trivial example below.
I am using Labview 8.6 professional.
Thank you and best regards!
K
https://decibel.ni.com/content/blogs/kl3m3n
"Kudos: Users may give one another Kudos on the forums for posts that they found particularly helpful or insightful."

Your Vision Development Module seems to be too old. Support for U16 was covered partially in early versions. Try version 2010 or latest Vision 2011 - for me IMAQ Mask works with U16 image. Both VDM 2010 and 2011 are compatible with LabVIEW 8.6.
Andrey.

Image display scroll bar

Hi All,
I am using two "Image displays" in my IMAQ vision system. One is for the original image and the other is for the image after it has been manipulated. I would like to connect the scroll bars from each display to move as one. Anyone have any idea how to do this?
Don

Here is a present from Santa. It is in LV 8.0. Enjoy
Matthew Fitzsimons
Certified LabVIEW Architect
LabVIEW 6.1 ... 2013, LVOOP, GOOP, TestStand, DAQ, and Vison
Attachments:
IMAQtrackImages.vi ‏62 KB

Imaq windraw vs. Imaq image display

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