Delay Using IMAQ Image

Hi
I am using ProGres Speed XT Core 5 camera and its library. I would like to make some image processing with labview therefore I visualize the images by IMQ Image instrument. Unfortunately I have small delay of image transfer. Could you please see my code here.
Best regards
Attachments:
CameraControlIMAQImage.vi ‏129 KB

Hi,
You can use the information from this community page that explains how to benchmark a simple code
https://decibel.ni.com/content/docs/DOC-12892
Basically you have to isolate your image processing which are two VIs inside the sequence structure and measure how long it takes.
Also, where can I find the driver you are using it? It will help me understanding what exactly you are trying to do and I can come with suggestions for improving it.
Regards,
IR

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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).
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I am currently using LabVIEW 8.0 with the latest IMAQ/NI Vision package from NI (IMAQ v7.1?). Thanks.
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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.
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Using IMAQ Image controls in LabVIEW steps

Hi guys
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Vladimir
Solved!
Go to Solution.
Attachments:
ft5.vi ‏5 KB

Hello Vladimir,
Thank you for posting on the NI Discussion Forums. This was reported to R&D (#123249) for further investigation. The only workaround I can offer for now is to work with the VIs from version 8.5 of LabVIEW if they have vision controls linked to the connector pane. Thanks for the feedback!
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"IMAQ image to string" difference in 8.2 and 8.5

My basic aim is to capture image from one computer and then send to another in LAN using TCP/IP. I have LabVIEW 8.5 and LabVIEW vision 8.5 in one and LabVIEW 8.2 and LabVIEW vision 8.2 in another. I capture an image in the computer whear I have installed 8.2 version of both and then flattened using " IMAQ image to string" and then sent it to computer using TCP/IP to computer with 8.5 version but the image is not displayed whearas when i do send that from 8.5 to 8.2 ( Capture the image in the computer with 8.2 and then flatten it to string and send it to the computer with 8.5 and display) , it works. Is it beacuse of different version of LabVIEW vision?

Hi aman_bajra,
You should be able to pass the image from one computer to another using TCP/IP, even if the computers have different versions of the Vision Development Module installed. I tested this here and I had no difficulty sending the image from a computer running Vision 8.5 in LabVIEW 8.5 to a computer running Vision 8.2 in LabVIEW 8.2, or vice versa. FYI, I used the normal Flatten to String node, not the IMAQ Image to String VI. I have included the VIs I used to do this below. Please give these a try and reply back if you are still unable to send your image properly. Thanks.
Rishee B.
Applications Engineer
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Message Edited by risheeb on 03-12-2008 12:24 PM
Attachments:
TCPIP Receive Image3.vi ‏45 KB
TCPIP Send Image1.vi ‏74 KB

IMAQ image to array vi not working with images extracted from avi file

Hi,
I downloaded some avi's and uncompressed them so that I can analyze them within labview. I am trying to convert images I am reading from the avi file to an array. When I use "IMAQ image to array" I get the following error " IMAQ Image To Array Invalid image type" -1074396080.
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Attachments:
example2.vi ‏62 KB

Hi all, this thread was useful for me...but i have another doubt... when I try to extract a single plane (Luminance, Saturation, R,G,B...anyone) and try to save it in jpg as gray image, it saves an image with blue tones. I have examinated it using Matlab and checked that Red plane has low values (but not zero), the same for G plane and high values for B plane. An image of the VI is attached.
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Attachments:
planes.png ‏28 KB

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I am currently opening and manipulating (rotate and resize) a PNG image using IMAQ Vision in LabView 8.2.1 This works well and I can display the Image on the front panel using a IMAQ Image Control.
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Hi Randall
Apologies for replying somewhat late but I have been out of the office for a few days.
Your suggestions and code helped me greatly and led to solving my query so thank you for that.
There is one more thing (well many many more but I will place new posts for those however that you might be able to answer for me.
Following your suggestion to use the image to array function I searched through more examples and found the code that did exactly what I wanted to do. Please see attached.
In this code a For loop is used to add 65793 to the color table. It works very well but I do not know why it is used exactly. Can you exlplain? I also realize I never made it clear that I use grayscale PNG files rather then color images.
Thanks again for your excellent help, it is much appreciated.
Attachments:
IMAQ_8-bit_to_picture v1.vi ‏15 KB
Test Image.png ‏42 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.
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TIA

With Vision 2009 situation is not better.
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The number of shifts is the number of bits that will be chopped (in the dark regions) from the initial image to fit into 8 bits.
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Using IMAQ create, set-up, acquire and windraw to save image without color map

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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.
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How to reverse an image acquired using IMAQ APIs in vc++

how to reverse an image acquired using IMAQ APIs in vc++

When using imaqFlip, may the source and destination be the same Image* ?
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What datatype should i use to store imaq image in sql database?

Hi there i am thinking of saving the imaq image into database for retrieval in my website so that it's like a stream but i don't like what datatype does labview store the image as.

You have two options for storing images in a relational database:
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B. Store it as a blob datatype. See here for more info.

IMAQ Image to LabView Picture

Hello,
I am using XY Graph to display GPS data, XY graph also displays a map that is being preprocessed using vision functions to display correct part of image data, fit the scale etc.
Everything works fine, but the standard conversion way
takes long (25 ms). It becomes user unfriendly, when every scale / move of the XY graph introduces a delay.
The IMAQ vision preprocessing takes about 25ms too, together with some other calculations, the user response is about 60ms and it is just so - so to use.
I am hoping, to cut some processing time over here, becouse it it just flattening of an array.
I started making my own IMAQImage2LVPic function, but little success, since I do not understand the Image format of the LVPicture, I keep getting deformed images, memory violations and it becomes frustrating.
The memory structure of the LVPicture would be great to know. Please help.
Solved!
Go to Solution.

The most likely reason that it is taking so long is that memory resources are redundant several times for this operation. The image data type defies the usual LabVIEW paradigm, as it is essentially a pointer to an array of pixel data rather than the actual data itself. This makes sense because images are fairly large memory chunks, and if you can operate on them and then stick them back in the same place you found them, you really won't cost yourself much RAM. That is how image manipulation generally works.
However, this changes when you want to bring the actual array data into LabVIEW. When you convert the image to an array, you are reallocating the image. It now exists in the location pointed to by the image wire, and it exists in LabVIEW RAM "on the wire." It is reallocated again when put into the cluster, then reallocated a few more times when calling the Draw Flattened Pixmap VI. At the end, it is flattened to string, which is another allocation, and then concatenated with header data and so forth, which is yet another memory allocation. (By the way, the picture data type is essentially a string full of flattened data). By the end of the whole deal, you have half a dozen or more copies of your image in RAM. That is costly and time consuming, however, when dealing with arrays directly, which is what this method is doing, it is difficult to avoid this because any time you change the size or change the datatype, you are reallocating all of that data again.
I would suggest going the other way, and trying to use the image data type and use IMAQ and Vision functions. The benefit is that these are designed specifically to handle large arrays of deep data and perform multiple operations on them with minimal memory reallocation. That is why the data type itself is a pointer rather than actual data.
Wes P
Certified LabVIEW Developer

How to use IMAQ extract color panel in a LabView file?

I want to change a color image into a greyscale image. Therefore I want to use the function IMAQ extract color panels but I don't know how to insert it in my LabView application.
Please, can anyone give me some advice ?!!!
Thx, Birgit

Birgit,
If you want all of the color planes, you can use IMAQ ExtractColorPlanes. Allocate an 8-bit image for each of the color planes. Wire the original color image and each of the 8-bit images for the color planes on the left and bottom of the vi. The outputs on the right side will be the same images, and they will each contain the desired color plane. The input at the top of the vi controls which color planes are extracted (RGB, HSI, etc.) Grayscale will probably be the I plane in HSI.
If you just want a grayscale image, use IMAQ ExtractSingleColorPlane instead. Wire the color image to Image Src, and wire an 8-bit image to Image Dest. Select the color plane using the top input, and it will come out on the right side.
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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

How do I convert an IMAQ image buffer into an IMAQ Vision 'Image'?

Using NI IMAQ and IMAQ Vision with LabWindows/CVI 6.0...
I have some acquisition code that uses IMAQ img functions to set up a
triggered image acquisition and stores the image into an 1D unsigned char
array buffer.
I would now like to add code that uses the IMAQ Vision functions. The IMAQ
Vision function use an Image data type, which from what I can glean from the
..h files, is a structure.
Is it possible to convert the 1D unsigned char array image buffer to an
Image? How would I do this?
An inefficiant brute-force way would be to write the image to a BMP file
from IMAQ using imgSessionSaveBufferEx, then read the same file back in
using IMAQ Vision imaqReadVisionFile. I am hoping there is a more elegant
way to perform the conversion in memory without needing to write disk files.
Thank you,
Robert Rafuse
Etec, Inc.
tel: (978)531-5025
e-mail: [email protected]
web: http://www.etec-inc.com

Bob Rafuse wrote:
> Is it possible to convert the 1D unsigned char array image buffer to
> an Image? How would I do this?
Never mind. I found:
http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3F11556A4E034080020E74861&p_node=DZ52490&p_submitted=N&p_rank=&p_answer=&p_source=External
which indicates that the img functions actually return a 2D array, so I can
use imaqArraytoImage after all.
My bad.
Bob

Delay Using IMAQ Image

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