Save original image (.png) even when zoomed

问题:

I have an apps that let the user to add text/image to the main image, and the main image can be zoomed.

My current problem is the produced PNG file is also zoomed if the main image is in zoomed position. My code is saving whatever is displayed to the user, instead of keeping the original image. I currently use getDrawingCache() method.

How to let the user zoom in/zoom out my main image but saving the original image instead of the zoomed image?

Thanks