Sampling and estimation

Abstract

Multimedia signal processing begins with the taking of physical measurements to acquire sounds or images. To determine what measurements are needed, we use a mathematical model of the physical process. For example, speech recording begins with a model of the sound vibrations that a human being can produce. These result in slight fluctuations of the air pressure that can be measured by a microphone, producing a real-valued function of one real “time” variable. Similarly, taking a picture begins with a model of the light arriving at the camera. The amount that arrives during the acquisition period, or when the shutter is open, is a nonnegative real-valued function of two “space” variables. Finally, video can be modeled by a nonnegative function of one time plus two space variables.