Capturing grayscale images and writing U32 data to binary file?

[tm473]

I'm new to using LabVIEW for image applications and am trying to capture grayscale images.  Because I'm feeding them into a queue, I need to convert the LabVIEW image file to a 2D array which I can pass into the queue.

The VI "IMAQ ImageToArray" seems ideal for this purpose, however, when I capture grayscale images in U16, I receive an error that the image I'm passing in is an invalid image type.  Using "IMAQ ColorImageToArray" works when I'm capturing in U32 and U16, but is unnecessary as I don't need RGB, only grayscale.  Ideally, I would be saving a simple 2D array of values from 0 to 255 which could easily be read into other programs.

When I save the U32 pixel data to a binary file and try to read it into Matlab (using fread(fid,[rows,columns])), about every fourth row of data is all zeros.

I've attached a simplified VI of what I'm doing, as well as what the image looks like in Matlab.  Am I missing something in terms of U32/U16 data types?  Any suggestions?  Many thanks in advance.

[Lennard.C]

Hi tm473,

Perhaps you could try something like the following link: https://decibel.ni.com/content/docs/DOC-32568. 

After you convert the colour image to greyscale image, perhaps you can use the "IMAQ ImageToArray" to convert that grescale image back to array.

Hope that helps

Warmest regards,

Lennard.C 

[tm473]

Hi Lennard,

Thanks very much for your response!  Unfortunately the link isn't working for me.

While I didn't actively solve the image-->array-->image issue I was having, for reference for others, I changed my architecture to follow this example: https://decibel.ni.com/content/docs/DOC-25670

Best,

Tracy

[Lennard.C]

Hi tm473,

Actually the reason why it can't work is because of the full stop at the end of the link (not sure why the forum thinks this is a part of the link). Try this amended link:

https://decibel.ni.com/content/docs/DOC-32568

Hope that helps

Warmest regards,

Lennard.C

[tm473]

Thanks, Lennard.

[Lennard.C]

Hi tm473,

I was able to modify the examples from the link I have given as shown below:

However, I was only able to get U8 data array from the grey scale. I doubt converting it to U32 would make much of a difference either.

Hope that helps

Warmest regards,

Lennard.C