Disable image cleansing for public facing form uploads
The imageDriver setting just determines which driver Craft should use when working with images (GD or ImageMagick) for things like image cleansing and image transforms. So changing its value will not affect whether images are cleansed on upload; just which driver would be used for that process.

If you want to disable image cleansing on the front end, you will need to write a plugin that handles the upload. You can find out how to do that from this answer: https://craftcms.stackexchange.com/a/9675/9