Why don't you take the invoke node get image from the intensity graph? This will give you the image with overlay immediately. Further processing is possible with picture VIs.
Ultimately need the merged image in 2d array format to further process, not in picture control. I have used what you suggest for other applications for purposes of saving a picture with overlay to bmp file. I actually forgot about this until you brought it up. It might work if I can take the image data from the cluster and it contains the overlay. I neglected to test this option and will try it this weekend.
Piecing together some subVIs to allow conversion of the image data cluster to actual image array, the approach you suggested seems to work quite well. I am attaching the code. Thanks again.
