Trouble saving image from CCD

[timothykinney]

I have an Andor Newton EMCCD Camera which I am interfacing with Labview 8. I have modified a VI supplied by Andor for capturing cooling the camera and capturing data. The data returns from the Acquisition vi as a 1D array. It is reshaped into a 2D array and then viewed on an intensity graph that is 1024 x 256 (the number of pixels on the camera). This works fine- the image is shown as blue and black in the intensity graph (although greyscale would be preferred). If I try to flatten pixmap and save the image as a jpeg, the image looks different. It seems to have lost detail, even if I turn it into a 24 bit pixmap.

Below is an image that I got using Andor's software. You can see two emission lines showing as bright regions across a grey background. The same image is shown as blue and black on the Labview output, and the bright lines are very hard to distinguish.

I'm not sure what I am doing wrong. How do I take data acquired from the CCD and output it as a jpg? Why does it look great as an intensity map but it doesn't work in jpg format?
If you want me to post the vi, just let me know.

-Tim

ANDOR Image (desired):


LABVIEW image (want it to look like Andor image):

[Matt_W1]

It's probably a bug somewhere with your VI. So we'll need to see that (with a sample array of the data, that works in the intensisty chart but not saved).

You can post attachments and link to them to add pictures. Like so (your image host doesn't like hot linking).

Andor


Labview





Message Edited by Matt W on 01-11-2008 03:48 PM

[timothykinney]

Find attached the portion of the code that doesn't seem to work.

[Matt_W1]

Can you run your vi on your machine, copy the Intensity Graph, and click on the copy and make it current value default. Then save and upload that VI (I don't have any sample data, to check against with the current upload).

I suspect your problem has to do with you using a 32 bit intensity number (one number representing how bright it is), but the flatten pixmap expects a 24 bit color value (each 24 bit value is made of 8 bit red,green,and blue components). Assuming that is the case you'll need to remap your 0 to max output camera numbers (2^(bit depth of camera)-1) to 0-255, and set each of the rgb components of each pixel to that value. You might be able also save in PNG which should support 16bit values but I don't think pixmaps support 16bit values.

Matt W.

[timothykinney]

Matt,

What you're saying is starting to make sense. I am out of the lab at the moment, but I will get the intensity graph values and post them when I can. Thanks for your time.

[timothykinney]

Okay, I did as you asked with the copy. This is the whole VI now- not just the relevant part. I think it should open up to the part in question. I labelled the copied intensity graph in the block diagram as "Copy of Intensity Graph at Run Time".

Thank you for your time.

[Matt_W1]

It was right about the color conversion.

Here's a quick example of how to remap the colors and put it into a pixmap (there's a decent chance that's there's a easier way to do this that I'm missing).
Note: the pixmap image is flipped about the X and Y axis, you can reverse the intesity chart data columns and rows to fix this.
Also I'm remaping from the intensity chart's min and max color's, you may need to use different values in your application.

Matt W

[dalli]

I downloaded :
software or max
IMAQ module or the module or imaqdx
and the driver of my camera
but I was unable to detect the camera or max? why?

[GuenterMueller]

Hijack of this thread that seems to be related to this question by the same author.