1. Chapter 1

2. Signal processing: Signal processing is concerned with the efficient and accurate extraction of information in a signal process. Signal processing provides the methods and tools for the extraction of information from signals. The application of signal processing involves TV, radio, cellular mobile phones, radar, sonar etc.

3. Chapter 1 Signal : A signal is a means of conveying information. Examples Imaging radars calculate the round trip delay of reflected light bouncing from the surface of the earth in order to produce the maps of the earth. Astrophysicists analyze the light and other waves emitted by the distant stars and galaxies in order to deduce information about them.

4. Chapter 1 The information conveyed in a signal may be used by humans or machines (computer or robots) for communication, forecasting, decision making etc. The type of signal that signal processing system deals with include text, image, audio, video, ultrasonic signals etc.

5. Chapter 1 Noise : Noise can be defined as the unwanted signals that interferes with the communication of another signals. Noise itself is information bearing signal that conveys information regarding the source of noise. Example The noise from the engine of a car conveys information regarding the state of engine and how smooth it is running.

6. Chapter 1 Application of signal processing: 1)Digital water marking : Digital water marking is the embedding of a signature signal, i.e the digital watermark, underneath a host image, video or audio signal. The main challenge in water marking is to make the watermark secret imperceptible(invisible and inaudible). Watermarking is used in digital media for the following purposes.

7. Chapter 1 1)Authentication of digital image and audio signals. Watermark also includes owner information, a serial number and other useful information. 2)Embedding of audio or text signals into image/video signals for retrieval. 3) Embedding a secret message into in to an image or audio signal.

8. Chapter 1 Bio medical signal processing : Bio medical signal processing is concerned with the analysis, denoising and synthesis of bio-signals such As magnetic resonance image of the brain and or electrocardiograph ( ECG) signals of the heart. An electrocardiograph signal is produced by recording the electrical voltage signals of the heart.

9. Chapter 1 Echo cancelation : Echo is repetition of a signal back to the transmitter either due to the coupling between the loudspeaker and microphone or due to a reflection of the transmitted signal from the points or surfaces where the characteristics of the medium through which the signals propagates changes so as to impede the propagation of the signal in the original direction such that some of the signal energy is reflected back to the source. Echo can severely affect the quality of vice conversation in telephone etc.

10. Chapter Modern communication system use echo cancelation system that identify the echo path and synthesis the signal and then subtract the echo signal from the original signal.