Overlaying And Setting Image Transparency

[Mic_Scale]

Hello guys,

I'm working on Labview 7.1 and Imaq Vision. I'm working with grayscale images.

I'm trying to build an application, which enables to take two different images (which in fact are of the same object) and then allows the user to allign them one on another, so that their features would fit.

This is done for calibration purposes. Now, for this I would like to be able to set the image, which is overlayed on the first, with some degree of transparency, so that the underlying image would be seen too.

Also, I would like the underlying image to be transformed from black and white image into black and blue image, so that the differences between the images would be seen sharply.

How can I do those two things ?

I'll be glad to get some help.

Thanks.

[David S.]

Hi Mic_Scale -

I think you can approach both requirements of this task simultaneously.  NI Vision doesn't currently support image transparency.  However, since you're working with grayscale data and not color images, you merely manipulate the planes of a color RGB image.  For instance, if you have two 8-bit grayscale images that you want to overlay, you can write the data from each into the R and G planes of an RGB24 image.  When displayed, these planes will appear semitransparent on each other.  (For more distinct emphasis, you can use the R and B planes.  The G plane would be zero.)

I've attached a quck-and-dirty example VI to help explain.

Message Edited by David S. on 06-13-2006 02:02 PM