Chapter 5
Image Sensing and Acquisition
What will we learn?
- What are the main parameters involved in the design of an image acquisition solution?
- How do contemporary image sensors work?
- What is image digitization and what are the main parameters that impact the digitization of an image or video clip?
- What is sampling?
- What is quantization?
- How can I use MATLAB to resample or requantize an image?
5.1 Introduction
In Chapter 01, we described an image as a two-dimensional (2D) representation of a real-world, three-dimensional (3D) object or scene and indicated that the existence of a light source illuminating the scene is a requirement for such an image to be produced. We also introduced the concept of a digital image as a representation of a two-dimensional image using a finite number of pixels.
In this chapter, we will expand upon those concepts. More specifically, we will look at relevant issues involved in acquiring and digitizing an image, such as the principles of image formation as a result of reflection of light on an object or scene, the sensors typically used to capture the reflected energy, and the technical aspects involved in selecting the appropriate number of (horizontal and vertical) samples and quantization levels for the resulting image. In other words, we will present the information necessary to understand how we go from real-world scenes to 2D digital representations of those scenes. For the remaining chapters of Part I, we shall assume that such digital representations ...
