Image Processing: Overlaying segments from an image over one another?

I have created two B&W images from a RGB image and want to overlay them but have not figured it out. I would need to change the white color on one of the two output images and then remove the black background for the image with the red circles so i could then overlay it on top of the other image.

FYI Images are the same size.

Any suggestions? I am also open to revisions to code. My code thus far is attached.

Thank you

[Image Analyst]

You forgot to attach your createMask() function. Please do so.

In the meantime, check out imoverlay() or these links:

https://blogs.mathworks.com/steve/2006/03/28/image-overlays/

http://www.mathworks.com/matlabcentral/answers/104889-how-to-overlay-a-foreground-image-over-a-background-image

[Nick]

Thank you for catching that, I have attached the createMask code.

I will look into the links you provided. Thank you