What java library to use to change camera image?

I am currently creating an application that takes a picture using the phone’s camera. The application will be used for customers who are pre-op for breast augmentation. The user will be able to photograph himself, and then place two images on the image, and then use the slider to manipulate the size of the spheres. This will give the user an idea of ​​what size cup they need. I understand that there is something in Photoshop that has the desired effect, and this is what I am trying to replicate, but to the bitmap.

Are there any suitable libraries that I can use. I look at OpenGL as 3D graphics.

Any ideas and input would be appreciated.

thanks Mat.