Contents
Preface
Editors’ Acknowledgements
Author Biographies
1. Introduction to the imaging process
Introduction
The imaging process
Image control
Control of image shape
Depth of field
Tone and contrast
Colour
The origins of photography
Camera obscura
Early experiments
Towards the development process – the Daguerreotype
The negative–positive process
Modern materials
Photographic imaging today
Characteristics of photographic materials
Capturing colour
Digital imaging
Early digital images
The CMOS sensor
Colour digital capture
Other digital devices
Digital image representation
Spatial resolution
Bit depth
Colour representation
File size and file formats
Imaging chains
Evaluating image quality
Bibliography
2. Light theory
Introduction
A brief history of light theory
Wave–particle duality
The nature of light
Radiometry and photometry
Radiometric definitions
Photometric definitions
Optics
Wave theory
Simple harmonic motion
Principle of superposition
Plane waves
Light intensity
Refraction and dispersion
Polarization
Interference
Diffraction
Diffraction of a circular aperture and a single slit
Rayleigh criterion
The electromagnetic spectrum
Black-body radiation
Wien’s Displacement Law
Planck’s Law
The photoelectric effect
The photon
Bohr model of the atom
The emission of electromagnetic radiation in atoms
Bibliography
3. Photographic light sources
Introduction
Characteristics of light sources
Spectral quality
Spectral power distribution curve
Colour temperature
Colour rendering
Percentage content of primary hues
Measurement and control of colour temperature
The mired scale
Light output
Units
Illumination laws
Reflectors and luminaires
Constancy of output
Efficiency
Daylight
Tungsten filament lamps
Tungsten–halogen lamps
Fluorescent lamps
Metal-halide lamps
Pulsed xenon lamps
Expendable flashbulbs
Electronic flash
Flash circuitry
Flash output and power
Flash duration and exposure
Portable units
Studio flash
Automatic flash exposure
Integral flash units
Red-eye avoidance
Other sources
Light-emitting diodes
Diode lasers
Bibliography
4. The human visual system
Introduction
The physical structure of the human eye
Tunics
Cornea
Conjunctiva
Iris and pupil
Crystalline lens
Ciliary body
Vitreous cavity and vitreous humour
Retina and choroid
Optic nerve
Structure of the retina
Rods and cones
‘Non-imaging’ cell layers
Receptive fields
Dark adaptation
Elementary colour vision
Young–Helmholtz theory of colour vision
Opponent theory of colour vision
Colour anomalous vision
Movement and Focusing
Focusing and correction of eyesight
Movement
The visual pathway
Visual cortex
Binocular vision
Performance of the eye
Luminance discrimination
Contrast sensitivity function
Visual acuity
Animal vision
Bibliography
5. Introduction to colour science
Introduction
The physics of colour
Colour terminology
The colour of objects
Spectral absorptance, reflectance and transmittance
CIE standard illuminating and viewing geometries
CIE standard illuminants and sources
Models of colour vision
The basics of colorimetry
Colour matching functions and the CIE standard observers
Calculating tristimulus values from spectral data
Chromaticity diagrams
CIE uniform colour spaces and colour differences
Metamerism and types of metameric matches
The appearance of colours
Visual adaptation and related mechanisms
Other colour appearance phenomena
An introduction to CATs and CAMs
A generalized CAT
Colour appearance models (CAMs)
Colour reproduction
Objectives of colour reproduction
Instruments used in colour measurement
Viewing conditions
Bibliography
6. Photographic and geometrical optics
Introduction
Photographic optics
Optical materials
Reflection
Refraction
Transmission
Dispersion
Polarization
Geometrical optics
Simple lens
Cardinal planes
Focal length
Image magnification
Mirrors
Optical calculations
Parameters
Equations
Focusing movements
Depth of field and depth of focus
The photometry of image formation
Stops and pupils
Aperture
Image luminance and illumination
Image illuminance
Exposure compensation for close-up photography
Lens flare
T-numbers
Anti-reflection coatings
Types of coating
Bibliography
7. Images and image formation
Introduction
Sinusoidal waves
Modulation
Images and sine waves
Imaging sinusoidal patterns
Fourier theory of image formation
Linear, spatially invariant systems
Spread functions
The point spread function (PSF)
The line spread function (LSF)
The edge spread function (ESF)
The imaging equation (from input to output)
The imaging equation in one dimension
The modulation transfer function (MTF)
Special Fourier transform pairs
The rectangular function
The Dirac delta function
Properties of δ(x)
Importance of δ(x)
The Gaussian function
The modulation transfer function revisited
Cascading of MTFs
Convolution revisited
A geometric interpretation of convolution
The convolution theorem
Discrete transforms and sampling
Undersampling a cosine wave
The Dirac comb (the sampling function)
The process of sampling
The MTF for a CCD imaging array
Bibliography
8. Sensitometry
Introduction
The subject
Exposure
Density and other relevant measures
Transmittance
Opacity
Density
Effect of light scatter in a negative
Callier coefficient
Density in practice
The Characteristic (H and D) curve
Main regions of the negative characteristic curve
Variation of the characteristic curve with the material
Gamma–time curve
Variation of gamma with wavelength
Placing the subject on the characteristic curve
Effect of variation of exposure of the negative
Average gradient and Ḡ
Contrast index
Effect of variation in development on the negative
Exposure latitude
The response curve of a photographic paper
Maximum black
Exposure range of a paper
Variation of the print characteristic curve with the type of emulsion
Variation of the print characteristic curve with development
Requirements in a print
Paper contrast
Reciprocity law failure
Practical effects of reciprocity failure
Intermittency effect
Sensitometers
Densitometers
Microdensitometers
Colour densitometers
Bibliography
9. Image sensors
Introduction
Materials and detection of light
Conductors, insulators and semiconductors
Doping
Photoemission and photoabsorption
Diodes
Transistors
CCD and CMOS sensors
MOS capacitor
Photodiodes
Pixels
CCD and CMOS image readout
CCD readout
CMOS readout
Amplification and analogue-to-digital conversion
Scanning methods
Imaging performance
Performance trade-offs
Microlens arrays
Sensitivity
Exposure control
Sensor imperfections
Generating colour
Bibliography
10. Camera lenses
Lens aberrations
Introduction
Axial chromatic aberration
Lateral chromatic aberration
Spherical aberration
Coma
Curvature of field
Astigmatism
Curvilinear distortion
Lens aperture and performance
Photographic lenses
Photographic lens types
Simple lenses
Compound lenses
Development of the photographic lens
Simple lenses and achromats
The Petzval lens
Symmetrical doublets
Anastigmats
Triplets
Double-Gauss lenses
Modern camera lenses
Wide-angle lenses
Symmetrical-derivative lenses
Retrofocus lenses
Fish-eye lenses
Long-focus lenses
Long-focus designs
Telephoto lenses
Catadioptric lenses (‘mirror lenses’)
Zoom and varifocal lenses
Zoom lenses
Zoom lenses for compact and digital cameras
Macro lenses
Optical attachments
Afocal converter lenses
Close-up (supplementary) lenses
Other attachments
Teleconverters
Optical filters
Absorption filters
UV and IR filters
Neutral-density filters
Polarizing filters
Bibliography
11. Photographic camera systems
Introduction
Image format
Camera types
Simple cameras
Compact cameras
Rangefinder cameras
Twin-lens reflex (TLR) cameras
Single-lens reflex (SLR) cameras
Technical cameras
Special-purpose cameras
Cameras for self-developing materials
Aerial cameras
Underwater cameras
Ultrawide-angle cameras
Panoramic cameras
Automatic cameras
Analogue systems
Digital control
Camera features
Shutter systems
Flash synchronization
The iris diaphragm
Viewfinder systems
Focusing systems
Autofocus systems
Exposure metering systems
Automatic exposure
Programmed exposure modes
Segmented photocell systems
Battery power
Camera shake and image stabilization
Camera movements
Bibliography
12. Exposure and image control
Camera exposure
Exposure relationships and logarithms
Relative aperture
Shutter speed
Subject luminance ratio
Dynamic range of sensors
Optimum exposure and the transfer function
Exposure meters
Hand-held exposure meters
Acceptance angle
Exposure values
Exposure factors
Reciprocity law failure
Types of light measurement
Incident light measurement
Reflected light measurement
In-camera metering modes
Spot metering
Partial area metering
Centre-weighted average metering
Matrix or multi-zone metering
Electronic flash exposure
Guide numbers
Reflected light measurement techniques
Measurement of total scene luminance
Measuring a middle grey surface (key tone)
Measurement of luminance of the darkest shadow
Measurement of luminance of the lightest highlight
Averaging values
Exposure techniques and digital cameras
Using the image histogram
‘Exposing to the right’
The zone system
The zones
The zone system and digital cameras
High-dynamic-range (HDR) imaging
Bibliography
13. Image formation and the photographic process
Introduction
Silver halides
Latent image formation
Spectral sensitivity of photographic materials
Response of photographic materials to short-wave radiation
Response of photographic materials to visible radiation
Spectral sensitization
Orthochromatic materials
Panchromatic materials
Extended sensitivity materials
Infrared materials
Other uses of dye sensitization
Structure of photographic materials
Production of light-sensitive materials and sensors
The support
Coating the photographic emulsion
Sizes and formats of photographic materials
Speed of photographic materials
Speed systems and standards
Characteristics of photographic materials
Graininess and granularity
Contrast
Sharpness and acutance
Chemistry of the photographic process
Developers and development
Composition of a developing solution
Developing agents
Preservatives
Alkalis
Restrainers (anti-foggants)
Miscellaneous additions to developers
Superadditivity (Synergesis)
Development time
Printing
Darkroom work
Development
Bibliography
14. Digital cameras and scanners
Digital still cameras
Digital still camera architecture
Imaging optics
Image sensor
Shutter systems
Dynamic range in digital cameras
Colour capture
Three-sensor cameras
Sequential colour cameras
Colour filter array (CFA) cameras
The Super CCD™
The Foveon™ sensor
Rendered versus unrendered camera processing
Exposure determination and auto-exposure
Autofocus control
Analogue processing
Digital processing
Colour demosaicing
Setting white balance
Digital zoom, resizing and cropping
Noise reduction
Sharpening
Tone/colour rendering
Camera types
Compact digital cameras
Bridge digital cameras
Digital single-lens reflex (DSLR) cameras
Digital cameras and camera backs for medium and large format
Specialist digital cameras
Image scanners
Types of scanners
Drum scanners
Flatbed scanners
Film scanners
Flextight scanners
Multi-spectral scanners
Scanner characteristics
Sampling and resolution
Dynamic range
Bit depth
Scanning speed
Image transfer
Scanner drivers
Bibliography
15. Displays
Introduction
Image display
Cathode ray tube (CRT) displays
Liquid crystal displays (LCDs)
Other display technologies
Plasma display panels (PDPs)
Organic light-emitting displays (OLEDs)
Flexible displays
Characteristics of displays
Refresh rate and response time
Resolution
Luminance
Contrast ratio
Viewing angle
Colour
Display artefacts
Effect of viewing conditions
Bibliography
16. Digital printing and materials
Introduction
Printing technologies
Inkjet printers
Electrophotographic printers
Thermography
Pictrography
Printing media and their properties
Paper for inkjet printing
Inks for inkjet printing
Toner materials
Colour, resolution and output
Half-toning and dithering
Resolution
Printing press
Relief printing
Planographic printing (or lithography)
Recess printing
Through printing
Bibliography
17. Digital image file formats
Introduction
Raster and vector graphics
Bit-depth support and colour encoding
Compression methods
Standardization of the format
Metadata and Exif
Colour management
Additional features
Tagged image file format (TIFF)
TIFF/EP
TIFF/IT
Joint Photographic Experts Group (JPEG)
Joint Photographic Experts Group 2000 (JPEG 2000)
RAW
Digital negative (DNG)
Graphics interchange format (GIF)
Portable network graphics (PNG)
Photoshop document (PSD)
Photo CD (PCD)
Postscript (PS) and encapsulated postscript (EPS)
EPS
Portable document format (PDF)
Bibliography
18. Image storage and archiving
Introduction
Life expectancy of traditional photographic media
Processing conditions
Dark fading
Light fading
Storage conditions
Atmospheric gases
Toning
Life expectancy of digital prints
Printing technologies and media
Permanence factors and test for digital prints
Digital image storage and longevity
Magnetic storage
Optical disc storage
Other digital image archiving issues
Bibliography
19. Introduction to image quality and system performance
Introduction
Subjective and objective image quality
Image quality assessment
Basic image quality attributes (or dimensions)
The image quality circle
Further image quality attributes
Digital image artefacts
Distortion, fidelity and quality
Image distortion
Image fidelity
Image quality
The use of a reference image
Test charts and test scenes
Test charts
Test scenes
Image psychophysics
Psychometric scales
The psychometric function
Scaling methods
Scene dependency in image quality
Choice of test scenes
Image quality metrics and models
Bibliography
20. Speed and sensitivity
Sensitivity of imaging systems
Spectral sensitivity of digital cameras
Measurement of the spectral sensitivity of digital cameras
Determination of the colour sensitivity of an unknown photographic emulsion
Wedge spectrograms
Uses of wedge spectrograms
Speed of imaging systems
Methods of expressing speed
Threshold systems
Fixed density
Inertia
Minimum useful gradient
Fractional gradient
Speed systems and standards
ISO speed ratings for colour silver-based materials
Colour negative film
Colour reversal film
Speed of digital systems
Speed based on saturation (Ssat)
Speed based on noise (Snoise)
Standard output sensitivity (SOS)
Recommended exposure index (REI)
Digital camera ISO settings
Typical sensitivities of film and CCD devices and speed ratings in practice
Bibliography
21. Tone reproduction
Theory of tone reproduction
Transfer functions and gamma
Overall transfer function and overall gamma
Subjective tone reproduction, optimum gamma and viewing conditions
Quadrant diagram
Tone reproduction of imaging devices and image encoding systems
CRT display transfer function
Liquid crystal display (LCD) transfer function
Measuring display transfer functions
Transfer functions of digital acquisition devices
Measuring acquisition device transfer functions
Image encoding: sRGB, Adobe RGB and JPEG transfer functions
Transfer functions of printers
Other measures related to tone and contrast
Dynamic range and contrast ratio
Contrast in uniform areas, test targets and images
Non-linear quantization, bit-depth requirements and gamma correction
Bibliography
22. Photographic colour reproduction
Introduction
Complementary pairs of colours
Colour photographic processes
Additive colour photography
Subtractive processes
Integral tripacks
Formation of subtractive image dyes
Colour sensitometry
Negative–positive colour
Reversal colour
Colour photographic materials
Location of colour formers
Colour processing
Reversal process
Negative–positive process
Prints from transparencies
Enhancement of colour reproduction
Colorimetry of photographic images
Bibliography
23. Digital colour reproduction
Introduction
Colour space and colour encoding
Classification of colour spaces
RGB (red, green, blue)
CMY(K) (cyan, magenta, yellow, black)
HSL (hue, saturation, lightness) – and similar
YCC (luminance, chrominance 1, chrominance 2) – and similar
CIE colour spaces
Colorimetric colour spaces
Colour appearance spaces
Device dependent colour spaces
Image state
Sensor colour encoding
Scene-referred colour encoding
Output-referred colour encoding
Original-referred colour encoding
Standard colour space and colour space encodings
sRGB (standard RGB) and sRGB-related colour space encodings
sYCC and sYCC-related
ROMM RGB and RIMM RGB
Adobe RGB 1998
Device colour characterization
Physical models
Numerical models
Regression
Look-up tables with interpolation
Evaluation of the characterization model
Characterization of displays
Characterization of digital input devices
Gamut mapping
Gamut mapping aims
Gamut mapping techniques
Bibliography
24. Noise, sharpness, resolution and information
Introduction
Image noise
Causes of noise in an image
Photographic noise
Graininess
Factors affecting the graininess of prints
Granularity
Factors affecting negative granularity
Variation of granularity with density
Quantifying image noise
Variance
Estimating σ2
Selwyn’s law
The autocorrelation function
The noise power spectrum
Relationships between noise measures
Practical considerations for the autocorrelation function and the noise power spectrum
Using the autocorrelation function
Direct Fourier transformation of noise samples
Signal-to-noise ratio
Electronic system noise
Resolution, sharpness and MTF
Resolving power of photographic systems
Measuring modulation transfer functions
Wave recording – sine-wave method
Wave recording – square-wave methods
Edge input method
Slanted edge method
MTF correction
Resolving power and MTF for optical systems
Sharpness, MTF and image quality
Detective quantum efficiency (DQE)
General considerations
DQE for the photographic process
DQE for a CCD or CMOS imaging array
DQE and signal-to-noise ratio
Information theory
Information capacity of images
Bibliography
25. Digital image workflow
Imaging chains and image workflow
Principles guiding effective workflow
Workflow approach
Resolution and the digital imaging chain
Interpolation
Interpolation methods and associated artefacts
Interpolation and image workflow
Calculating required resolution for image output
Bit depth: 8-bit versus 16-bit imaging
Colour management
Colour workflow
File formats
Image acquisition
RAW capture and workflow
Image editing
Image output
Image archiving
Image optimization workflow
Workflow examples
1. Commercial photography
2. Forensic imaging
3. Medical imaging
Acknowledgements
Bibliography
26. Colour management systems
Introduction
Colour management tasks
Closed-loop versus open-loop colour management
The International Color Consortium (ICC)
ICC colour management architecture
The profile connection space (PCS)
Rendering intents
The ICC perceptual intent reference medium and reference viewing conditions
ICC profiles
Using profiles
Profile processing models
Profile structure
Structure of device profiles
Structure of colour space conversion profiles
Creating custom device profiles
Display profiles
Input profiles
Scanner profiling
Digital camera profiling
Using camera profiles
Output profiles
Colour management workflow
Colour rendering options
Early-binding versus late-binding workflow
RGB and CMYK workflows
Using an intermediate colour space
Proofing and soft-proofing images
Bibliography
27. Spatial image processing
Introduction
Background
Structure of the digital image
Implementation of spatial domain processes
Linear systems theory
Discrete convolution
Point processing operations: intensity transformations
Brightness and contrast changes using linear transformation functions
Piecewise linear functions
Image thresholding and quantization
Power-law transformations: gamma correction
Point processing: multiple image operations
Enhancement using arithmetic operations
Enhancement using logic operations
Point processing: statistical operations
The image histogram
Probability density function and probability distribution function
Histogram slide and stretch
Histogram equalization
Point processing: geometric transformations
Neighbourhood processing: spatial filtering techniques
Linear filtering
Properties of linear filters
Types of linear filters and their applications
Smoothing spatial filters
Edge detection and sharpening spatial filters
Non-linear spatial filtering
Median filters
Minimum and maximum filters
Bibliography
28. Digital image processing in the frequency domain
Introduction
Fourier series and transform revisited
Fast Fourier transform (FFT)
Imaging equation revisited
Linear spatial filtering (convolution)
Frequency-domain filtering
Low-pass filtering
High-pass filtering
High-boost filter
Band-pass and band-Stop filters
Image restoration
Inverse filtering
Optimal or Wiener filtering
Maximum entropy reconstruction
Interactive restoration
Extended depth of field (EDOF)
Wavelet transform
Discrete wavelet transform
Bibliography
29. Image compression
Introduction
Uncompressed image file sizes
Image data and information
Basis of compression
Types of redundancy
Measuring compression rate
Scene dependency and compression
Information theory
Entropy and image structure
Shannon’s theorem
Image compression models
Lossless compression
Lossless compression methods
Reducing spatial redundancy
Reducing coding redundancy: variable-length coding
Lossy compression
Evaluating lossy compression
Distortion metrics
Alternative assessment methods
Lossy compression methods
Quantization
Lossy compression standards
Joint Photographic Experts Group (JPEG) standard
JPEG 2000 standard
Bibliography
Appendix A
Appendix B
Index
