pixels intensity

[Uhryap]

Dear all,
I have iv, it changes the pixels intensity, but only for one individual shot. How should I make this operation in real time? It means, I have a web-camera, I give some light in this camera with the help of flashlight and in real time the intensity is reflacted. In attached files are vi for intensity and standard vi, it makes the screen capture from camera.
If it's possible, give me an idea, how can I receive the dimension of intensity from this camera in real time.
Thank you in advance for your reply.

[Irene B]

Hi Uhryap,

I'm a bit confused on your question and the VIs you provided.  The Grab with Property Page.vi looks like it does USB camera acqusition whereas the intensity.vi displays the histograph and the line profile of the ROI drawn.  However, I couldn't find any functions that actually alter any pixel intensities.  Would you please clarify your question please?  Also, what do you mean by "dimension of intensity"?  Thanks!

Cheers,
Irene Chow
National Instruments
Applications Engineer

[Uhryap]

For evident presentation of images of indikatrisy dispersion as impossible 3D images befit better. On them it is possible expressly to see the structure of bunch of radiation, by sight to compare the areas of most and the least intensity of radiation, and at presence of numeral information about general intensity – in number to estimate intensity of radiation in every point of the field. For creation of 3D images there is an instrument of IMAQ 3D View in LabView.

For work with a picture I created Raspredelenie intensivnosti.vi (which I add), a picture became job performances (which I add). How I must do so that my algorithm, realized in Raspredelenie intensivnosti.vi used not to the picture, but to video which is taken in real time and represents the changes of 3D image.

For me did not turn out to fasten files. Therefore I lay out them on http://www.yousendit.com/ and give reference http://www.yousendit.com/transfer.php?action=download&ufid=3279690624C0EB7C

[Uhryap]

Byuyt' can so it will be more clear.

It's possible to see on these 3D image (with indikatrisa of dispertion) the structure of beam of light, to compare visual the areas of maximum and minimum radiation intensity. If the numerical information about the total intensity is available, we can value the intensity in every point of field. To create 3D image in LabView we need the tool IMAQ 3D View.

For working with the picture I created Raspredelenie intensivnosti.vi (in attached file), the result of the work is the picture (in attached file). How can I do so, that my algorithm, who had been incarnated in my file 'Raspredelenie intensivnosti.vi',  would be adapt not to the picture file but to the video file.

[Irene B]

Hi Uhryap,

From what it sounds like, you are trying to do image acquisition as a Grab (a Grab means you are acquiring a series of images so that it looks like "live video").  While you are grabbing these images, you would like to change the image using the IMAQ 3DView VI.  The image source for Raspredelenie intensivnosti.vi is an image file saved on the computer hard drive, but it only reads in one picture because the File Dialog VI only occurs once (outside of the while loop).  

1)  If you want to use 3D view with images directly captured from the USB camera, you will need to make sure to call the IMAQ USB Grab VI inside the loop before IMAQ 3DView VI occurs.  That way, every picture that you grab will be transformed like "live video."  

2)  If you are looking to transform images from an AVI video file, you can use the AVI functions to read out one frame of the video out a time.  Examples of this can be found in the NI Example Finder (in LabVIEW, go to Help >> Find Examples and search for "AVI").  

Let me know if this is not what you are looking to do.

Cheers,
Irene Chow
National Instruments
Applications Engineer

[Uhryap]

Hello.

Thank you for answers. I beg pardon, for my English. I want to utillize IMAQ 3DView at a capture with USB of chamber, and that a picture changed in real time. That here this picture of ftp.ni.com/incoming/Intensivnost_.jpg changed in real time, at a capture with USB of chamber. Is it possible? I.e. I want, that ftp.ni.com/incoming/Raspredelenie intensivnostiþ.vi, worked with video in real time and represented changes in real time, for example at a capture with USB of chamber.

[Irene B]

Hi Uhryap,

Yes, as I mentioned before, you can try Option 1 in my previous post.  Instead of calling a saved image outside of the loop, delete that VI and place the USB camera Grab function inside the loop.  Place IMAQ 3DView after you acquire the image from the camera.  I was able to  replicate this successfully using the regular NI-IMAQ driver with an analog camera, but I don't have a USB camera with me because the NI-IMAQ for USB currently isn't supported by NI applications engineers.  One thing I should mention is that I had to a) use IMAQ Cast Image (because my camera was acquiring 16-bit images but the IMAQ 3DView only takes U8 or CSG images as see in the LabVIEW help) and b) I used another IMAQ Create to make a separate image buffer for the 3DView.

Cheers,
Irene Chow
National Instruments
Applications Engineer