I have been trying to launch a motion detection VI from this site: http://decibel.ni.com/content/docs/DOC-4717 .
I have already installed Vision Acquisition Software, Vision Development Module, and NI-IMAQ for USB Cameras. I am able to launch the VIs but the imige capture tool does not work. When I try to shut down the VI I get error messages:
- "No interface found" for NI-IMAQ version
- "Camera not found" for NI-IMAQdx version
I am sure the camera is OK because the system detects it and I can use it normally. So I open the Measurement & Automation Explorer to check for the connection, it shows no NI-IMAQdx Devices in the Devices and Interfaces. My whole configuration tree looks like this:
I guess the problem will go away if I will install some features but can someone tell me what should I look for?
a USB camera used with NI-IMAQ for USB Cameras won't be seen in MAX. To use it, you need to use block specific for this driver. You can find the details in the users manual.
I am working on an application where i need to interface my USB webcam in labview ! What should i do in order to interface my webcam and capture an image in order to process it afterward? Do we need the camera's driver?
If it's related to the NI-IMAQ driver, how can i use it ?
it all depends on what versions of software do you have.
Generally, acquisition from USB cameras it very simple if you have Vision Acquisition Software from August 2009 or newer. Then you don't need any additional drivers and can just plug the camera and use examples built in LabVIEW or some other programs available on Developer Zone, like the motion detection program posted above.
I have done with this part & i was able to find an example where there is an interface between the webcam i have and labview and i used it for capturing an image but i just wanted to ask another question ...
In the example of IMAQdx called sequence.vi (Express ) i tried to get 5 sequential images and i figured out some of the pixels values with the column number and row number and i found the image size and image type and coordinate information but i just want to ask that after i captured the image where will the pixels and the coordinate information be saved after capturing the image?
best regards !
I don't think I understand your question. You can save the data in any way you want (image file) but by default it isn't saved anywhere. What are you trying to achieve?
I was able to capture an image using Imaqdx express vi called sequence. My job is to retrieve some pixels for a tracking application.
I just wanna know that after capturing the image are the pixels and coordinate information saved anywhere? I mean where will the image matrix that contains the pixels be saved?
Hope u got my question right:)
you have the whole pallette of Vision blocks, that allow you to access single pixels, whole rows etc.:
The one accessing single pixel is IMAQ GetPixel Value.vi.
You can use the Developer Zone to search for examples showing how to use the IMAQ software in more complex applications.
Hope this helps.
Thank you for your help:)
Honestly i am trying to capture an image using the express vi example in IMAQ that allows me to get a sequence of images. My job is to capture an image for example and do some processing on it. Is there a way to capture the image using a webcam and directly do some processing on it without the need to save the image and retrieve it from another place to do the processing? I mean can i directly capture a photo from a webcam and do some processing on it? If yes then is there any example that allows me to access my webcam and process the captured image? or i have to save it first on the hard disk and then process it somewhere else?
I was able to access an example from motion and vision that is concerned with image management but the problem was that in order to process the image i had to browse it from the hard disk. What if my application is about object tracking and i have to capture a sequence of images and process them? should i always save the image on the hard disk which takes time because the hard disk is slow then process it afterward?
Hope the idea will be clear...
Thanks a lot !
why would want to save the image first?
Of course you can do the processing right after acquisiton.
Please have a look:
If you have problems grasping concepts of programming in LabVIEW, I would recommend you to have a look at these pages: