how to zoom a image in android

I have an image in Layout ,I will get the reference of that ImageView using findViewById() and I want to zoom it dynamically. Assuming its is vertical LinearLayout. How to d开发者_开发问答o Zooming dynamically in Activity?

This open source project does this and nothing more:
https://github.com/nicolas-raoul/AndroidBigImage/tree/master/template/src/fr/free/nrw/androidbigimage

Feel free to copy-paste (I maintain this project, by the way).

There is a problem for Android 1.5 devices, so I would be enchanted if anyone had a better solution!