This second edition of the fully revised and updated From Photon to Pixel presents essential elements in modern digital photographic devices. Our universal infatuation with photography profoundly affects its usage and development. While some sides of photographic “culture” remain wholly unchanged – art photography, journalistic and advertising photography, scientific photography, etc. – new facets emerge: leisure or travel photography, everyday life photography, anecdotal, observational or unusual photography, and microcosm, or micro-community, photography with its culmination in the narcissistic selfie. These new forms combine an often simplified manner of photographing and modern means of instantaneous, remote and mass communication. This book does not extend into the sociological study of photography, instead it explains how the digital camera works by examining in detail each of the components that constitutes it to provide the reader with a preliminary guide into the inner workings of this device.

Table of Contents:
Acknowledgements xi Chapter 1. First Contact 1 1.1. Toward a society of the image 1 1.1.1. A bit of vocabulary in the form of zoology 4 1.1.2. A brief history of photography 7 1.2. The reason for this book 10 1.3. Physical principle of image formation 11 1.3.1. Light 11 1.3.2. Electromagnetic radiation: wave and particle 12 1.3.3. The pinhole 13 1.3.4. From pinholes to photo cameras 15 1.4. Camera block diagram 21 Chapter 2. The Photographic Objective Lens 25 2.1. Focusing 26 2.1.1. From focusing to blurring 26 2.1.2. Focusing complex scenes 28 2.2. Depth of field 34 2.2.1. Long-distance photography 35 2.2.2. Macrophotography 36 2.2.3. Hyperfocal 37 2.3. Angle of view 38 2.3.1. Angle of view and human visual system 38 2.3.2. Angle of view and focal length 39 2.4. Centered systems 41 2.4.1. Of the importance of glasses in lenses 42 2.4.2. Chromatic corrections 45 2.4.3. The choice of an optical system 47 2.4.4. Diaphragms and apertures 50 2.4.5. Zoom 53 2.4.6. Zoom and magnification 54 2.5. Fisheye systems 57 2.5.1. Projection functions 57 2.5.2. Circular and diagonal fisheyes 59 2.5.3. Fisheyes in practice 61 2.6. Diffraction and incoherent light 63 2.6.1. Coherence: incoherence 63 2.6.2. Definitions and notations 65 2.6.3. For a single wavelength 66 2.6.4. Circular diaphragm 68 2.6.5. Discussion 70 2.6.6. Case of a wide spectrum 71 2.6.7. Separation power 73 2.7. Camera calibration 74 2.7.1. Some geometry of image formation 74 2.7.2. Multi-image calibration: bundle adjustment 77 2.7.3. Fisheye camera calibration 78 2.8. Aberrations 79 2.8.1. Chromatic aberration 79 2.8.2. Geometrical aberrations 80 2.8.3. Internal reflections 82 2.8.4. Vignetting 83 2.8.5. The correction of the aberrations 86 Chapter 3. The Digital Sensor 89 3.1. Sensor size 90 3.1.1. Sensor aspect ratio 90 3.1.2. Sensor dimensions 91 3.1.3. Pixel size 93 3.2. The photodetector 93 3.2.1. Image detection materials 93 3.2.2. CCDs 94 3.2.3. CMOSs 97 3.2.4. Back-side illuminated arrangement (BSI), stacked arrangement 101 3.2.5. Stacked arrangements 102 3.2.6. Influence of the choice of technology on noise 103 3.2.7. Conclusion 104 3.3. Integrated filters in the sensor 104 3.3.1. Microlenses 104 3.3.2. Anti-aliasing filters 106 3.3.3. Chromatic selection filters 109 Chapter 4. Radiometry and Photometry 111 4.1. Radiometry: physical parameters 112 4.1.1. Definitions 112 4.1.2. Radiating objects: emissivity and source temperature 116 4.1.3. Industrial lighting sources 122 4.1.4. Reflecting objects: reflectance and radiosity 123 4.2. Subjective aspects: photometry 125 4.2.1. Luminous efficiency curve 126 4.2.2. Photometric quantities 128 4.3. Real systems 128 4.3.1. Etendue 129 4.3.2. Camera photometry 130 4.4. Radiometry and photometry in practice 134 4.4.1. Measurement with a photometer 134 4.4.2. Integrated measurements 137 4.5. From the watt to the ISO 138 4.5.1. ISO sensitivity: definitions 138 4.5.2. Standard output ISO sensitivity SOS 143 4.5.3. Recommended exposure index 143 4.5.4. Exposure value 144 Chapter 5. Color 145 5.1. From electromagnetic radiation to perception 147 5.1.1. The color of objects 147 5.1.2. Color perception 149 5.2. Color spaces 151 5.2.1. The CIE 1931 RGB space 153 5.2.2. Other chromatic spaces 160 5.2.3. The Lab space 162 5.2.4. Other colorimetric spaces 163 5.2.5. TV spaces 164 5.2.6. The sRGB space 165 5.2.7. ICC profile 168 5.2.8. Chromatic thresholds 169 5.3. The white balance 170 5.3.1. Presettings 171 5.3.2. Color calibration 172 5.3.3. Gray test pattern usage 173 5.3.4. Automatic white balance techniques 173 5.3.5. The Retinex model 175 5.4. Acquiring color 178 5.4.1. “True color” images 181 5.4.2. Chromatic arrays 186 5.4.3. Chromatic selection of the arrays 192 5.5. Reconstructing color: demosaicing 195 5.5.1. Linear interpolation demosaicing 196 5.5.2. Per channel, nonlinear interpolations 199 5.5.3. Interchannel, non-linear interpolations 199 Chapter 6. Image Quality 205 6.1. Qualitative attributes 206 6.1.1. The signal–noise ratio 207 6.1.2. Resolution 211 6.1.3. The modulation transfer function 215 6.1.4. Sharpness 221 6.1.5. Acutance 221 6.2. Global image quality assessment 226 6.2.1. Reference-based evaluations 228 6.2.2. No-reference evaluation 230 6.2.3. Perception model evaluation 234 6.3. Information capacity 237 6.3.1. The number of degrees of freedom 238 6.3.2. Entropy 243 6.3.3. Information capacity in photography 245 6.4. What about aesthetics? 252 6.4.1. Birkhoff’s measure of beauty 253 6.4.2. Gestalt theory 254 6.4.3. Shannon information theory, Kolmogorov Complexity and Computational Complexity theory 254 6.4.4. Learning aesthetic by machine 254 Chapter 7. Noise in Digital Photography 257 7.1. Photon noise 258 7.1.1. Fluctuations in the optical signal 258 7.1.2. The Poisson hypothesis in practice 261 7.1.3. From photon flux to electrical charge 262 7.2. Electronic noise 265 7.2.1. Dark current 265 7.2.2. Pixel reading noise 266 7.2.3. Crosstalk noise 266 7.2.4. Reset noise 267 7.2.5. Quantization noise 267 7.3. Non-uniform noise 268 7.3.1. Non-uniformity in detectors 268 7.3.2. Salt-and-pepper noise 268 7.3.3. Image reconstruction and compression noise 268 7.4. Noise models for image acquisition 269 7.4.1. Orders of magnitude 270 Chapter 8. Image Representation: Coding and Formats 273 8.1. “Native” format and metadata 274 8.2. RAW (native) format 275 8.2.1. Contents of the RAW format 278 8.2.2. Advantages of the native format 280 8.2.3. Drawbacks of the native format 281 8.2.4. Standardization of native formats 281 8.3. Metadata 283 8.3.1. The XMP standard 283 8.3.2. The Exif metadata format 284 8.4. Lossless compression formats 286 8.4.1. General lossless coding algorithms 287 8.4.2. Lossless JPEG coding 288 8.5. Image formats for graphic design 289 8.5.1. The PNG format 289 8.5.2. The TIFF format 291 8.5.3. The GIF format 292 8.6. Lossy compression formats 292 8.6.1. JPEG 294 8.6.2. JPEG 2000 299 8.7. Tiled formats 304 8.8. Video coding 305 8.8.1. Video encoding and standardization 306 8.8.2. MPEG coding 307 8.9. Compressed sensing 310 Chapter 9. Elements of Camera Hardware 313 9.1. Image processors 313 9.1.1. Global architecture and functions 314 9.1.2. The central processing unit 315 9.1.3. The digital signal processor 318 9.1.4. The graphics processing unit 320 9.2. Memory 321 9.2.1. Volatile memory 321 9.2.2. Archival memory cards 321 9.3. Screens 327 9.3.1. Two screen types 327 9.3.2. Performance 329 9.3.3. Choice of technology 330 9.4. The shutter 333 9.4.1. Mechanical shutters 333 9.4.2. Electronic shutters 333 9.5. Measuring focus 335 9.5.1. Maximum contrast detection 337 9.5.2. Phase detection 340 9.5.3. Focusing on multiple targets 341 9.5.4. Telemeter configuration and geometry 342 9.5.5. Mechanics of the autofocus system 343 9.5.6. Autofocus in practice 344 9.6. Stabilization 346 9.6.1. Motion sensors 346 9.6.2. Compensating for movement 349 9.6.3. Video stabilization 352 9.7. Additions to the lens assembly: supplementary lenses and filters 353 9.7.1. Focal length adjustment 353 9.7.2. Infra-red filters 356 9.7.3. Attenuation filters 357 9.7.4. Polarizing filters 358 9.7.5. Chromatic filters 365 9.7.6. Colored filters 366 9.7.7. Special effect filters 367 9.8. Power cells 367 9.8.1. Batteries 368 9.8.2. Rechargeable Ni-Cd batteries 368 9.8.3. Lithium-ion batteries 369 Chapter 10. Photographic Software 373 10.1. Integrated software 374 10.1.1. Noise reduction 374 10.1.2. Classic approaches 375 10.1.3. Iterative methods 376 10.1.4. Non-local approaches 377 10.1.5. Facial detection 379 10.1.6. Motion tracking 382 10.1.7. Image rotation 384 10.1.8. Panoramas 385 10.2. Imported software 394 10.2.1. Improving existing functions 395 10.2.2. Creating new functions 395 10.3. External software 397 10.3.1. High-dynamic images (HDR) 397 10.3.2. Plenoptic imaging: improving the depth of field 402 10.3.3. Improving resolution: super-resolution 408 10.3.4. Flutter-shutters 412 Bibliography 417 Index 439