As what was stated on the header I want to implement either a "paint" or "eraser" function whichever feature more convenient for user to edit paint/censor unwanted parts of a photo displayed on a imageview before uploading it to a server in the edited format and a redo function if user makes a mistake while editing?

How do I come about doing it, I've read relevant topics on Canvas, or FingerPaint but still puzzled on how to implement it based on the scenario in this link here? Thanks for any help rendered!

idImage = (ImageView)findViewById(R.id.idImage);   
Bitmap bitmap = null;
bitmap = ImageLoader.init().from(photoPath).requestSize(512, 512).getBitmap();
idImage.setImageBitmap(bitmap);