[内容简介]
The principles of signal processing are fundamental to the operation of everyday devices such as digital cameras, mobile telephones and digital audio players. This book introduces the basic theory of digital signal processing, placing a strong emphasis on the use of techniques in real-world applications. The author uses intuitive arguments rather than mathematical ones wherever possible, reinforced by practical examples and diagrams.
The first part of the book covers sampling, quantisation, the Fourier transform, filters, Bayesian methods and numerical considerations. These ideas are then developed in the second part, illustrating how they are used in audio, image, and video processing and compression, and in communications. The book concludes with methods for the efficient implementation of algorithms in hardware and software. Throughout, links between various signal processing techniques are stressed and real-world examples showing the advantages and disadvantages of the different approaches are presented enabling the reader to choose the best solution to a given problem. With over 200 illustrations and oven 30 exercises (including solutions), this book will appeal to practitioners working in any branch of signal processing, as well as to undergraduate students of electrical and computer engineering.
[目录]
Preface ix
Foundations 1
Introduction 3
What is a signal? 3
Domain and range of a signal 3
Converting signals from one form to another 4
Processing signals 5
Notation 6
Sampling 10
Regular sampling 10
What is lost in sampling? 11
Examples of aliasing 13
Negative frequencies 15
The Nyquist limit 16
Irregular sampling 17
Conversion between analogue and digital 25
A simple digital signal processing system 25
Non-linear quantisation 28
How many bits do we need? 29
Dither 30
Non-ideal conversion 32
The frequency domain 37
Measuring rotational speed 37
More complicated motion 39
Interpreting the Fourier transform 42
How many Fourier coefficients are there? 43
Reconstructing a signal from its Fourier transform 43
Real signals 44
Dealing with non-periodic signals 49
The fast Fouriertransform 53
Filters 63
Smoothing a signal 63
Analysing a filter 66
Convolution in the frequency domain 74
Correlation 76
Designing FIR filters 77
Interpolation 83
Infinite impulse response filters 94
Filtering complex sequences 100
Likelihood methods 104
Probability and conditional probability 104
Probability and signal processing 109
Noise 111
Numerical considerations 124
Fixed-point representations 124
Negative numbers in fixed-point representations 135
Floating-point representations 139
Choosing between fixed point and floating point 143
Applications 147
Audio 149
The ear 149
Sample rates and conversion 149
Audio in the frequency domain 152
Compression of audio signals 154
Pitch extraction 163
Delta-sigma conversion 172
Still images 178
Luminance and chrominance 178
Gamma 179
An image as a signal 180
Filtering an image 185
The discrete cosine transform 193
JPEG compression for continuous-tone images 198
The discrete wavelet transform 202
Image scaling 209
Image enhancement 213
Edge detection 215
Processing of bilevel images 217
Pattern recognition 223
Moving images 231
Standard video formats 231
Deinterlacing 234
Standards conversion 239
Motion estimation 241
MPEG-2 video compression 246
Communications 253
Amplitude modulation 254
Frequency modulation 260
Quadrature amplitude modulation 263
Spread spectrum schemes 287
Implementations 299
Software implementations 300
Processor architectures 302
Hardware implementations 307
Bit-serial arithmetic 313
Answers 323
Index 329