This article describes how to create a reusable class that can upload images from our Gallery or take a picture, put them on a canvas and move them around the screen, resize them, erase them and convert them to black and white. This tutorial uses a class that extends View and uses onTouchEvents. This is class also takes care of the VM Budget issue of loading images from the gallery by optimizing the memory each image uses. It uses android 2.2 and above.
This article describes how to draw a bounding box on top of a camera preview to capture part of the image just like Google goggles does. This article mainly involves looking at a SurfaceView for generating a camera view and a View to create a canvas and draw on top of the camera view. Also shows how to use the onTouchInterceptEvent to pass touch events to lower Views. Android 2.2 API needs to be used for this.