Professional Android Sensor Programming

Chapter 13

Image-Processing Techniques

What's in this chapter?

Explaining how image-processing programs work

Using JJIL to do image processing

Example image-processing pipelines

In Chapter 12 you learned how to access and control Android's camera and to capture and process images. But there is much more to image processing than merely knowing how to capture images. Techniques have been developed over decades for dealing with a wide variety of problems in image processing, and these techniques can be applied directly to image processing in Android, with some care. This chapter shows you how to employ these techniques, first by describing the structure of image-processing programs in general, and then by illustrating image-processing program development with example programs.

The Structure of Image-Processing Programs

Image-processing programs have a characteristic structure that is driven by the need to transform large input images into a much smaller collection of meaningful results. The designers of image-processing programs take advantage of this characteristic structure in two ways: first, by designing data and control structures that match this characteristic structure, and, second, by developing algorithms that can be used again and again in different image-processing programs.

The Image-Processing Pipeline

Image-processing programs are generally structured as an image-processing pipeline: that is, they operate as a series of steps on images, starting with the input image, ...