How to handle raw data obtained from CCD using labview?

[Dushyant]

Hi,

The format in which CCD software saves its data is “16 bits TIFF” or “16 bits FIT format” (FIT format is just the raw data type). I am trying to save this data using labview. It’s not getting saved properly (I get 1 KB file in place of expected 1000KB +). I am using activex that came with my CCD. I am attaching the snap-shot of my screen and I have indicated the places by arrows where I am saving the image. What I believe is going on wrong is that I have not provided “data type” in “variant to data” function (as I do not know what to provide).

Please let me know your suggestion.

Thanks,

DK

[chilly_charly]

The data that you are passing as a variant is essentially a pointer to the image data, associated with some other image specific info. That's why the file size is so small.

To retrieve your image data, you need first to use the imageToArray function (in the Pixel Manipulation subpalette).

[Dushyant]

Thanks,

Now, it's making sense to me. I will try to do as you have suggested. I would let u know if I could not do it.

DK 

[Dushyant]

Hi,

I need some help. Actually the function that you are talking about is not on my lab pc, though I found that on my laptop. I think that I might not have installed some cd on lab computer. Do you have any idea about which cd may contain this function? I am asking because I do not want to reinstall evrything.

Thanks,

DK

Message Edited by Dushyant on 09-14-2005 01:38 PM

[chilly_charly]

You'll have to install the IMAQ vision development module. It's on a dedicated CD (wish NI decide to ship the LV suite on a DVD ! :))

[Dushyant]

Hi,

My CCD is malfunctioning. So, I could not test your suggestion. But, I believe that it should work.  However, I have a doubt that in "Variant To Data" there is one option of "type". What value I should provide. I can save the image as either “16 bits TIFF” or “16 bits FIT format” (FIT format is just the raw data type).

Just making sure that I am getting it right. "Variant To Data" would be followed by "IMAQ ImageToArray" with

"data" from "Variant To Data" to "image" from "IMAQ ImageToArray". Right?

Thanks for ur help,

Dushyant

Message Edited by Dushyant on 09-16-2005 06:39 PM

[chilly_charly]

Forget my previous reply.

I don't see on the diagram where you select the image type format.

I'm not sure you need the variant to data function. What happens when you wire directly the output of your image node to the image indicator ? Is your image displayed correctly ? I guess it is.

Once you have your image displayed properly, you should use the specific image save functions (in Vision > Vision utilities > files), and you don't need to go though the conversion to array step. JPEG, TIFF, BMP, PNG formats are available.