Introduction to Image Processing - Summary - G52IIP PDF

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G52IIP SummaryDigital Image Fundamentals ......................................................................................................... 5 Pinhole Camera ...................................................................................................................................... 5...

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G52IIP&Summary& Digital&Image&Fundamentals&......................................................................................................... .........................................................................................................& Digital&Image&Fundamentals& ......................................................................................................... " &5 Pinhole"Camera"......................................................................................................................................"5" Perspective"Projection"..........................................................................................................................."5" Forming"the"Image"................................................................................................................................."5 " CCDs$...................................................................................................................................................$5" Radiometric"Image"Model"......................................................................................................................"5" Sampling"................................................................................................................................................."6" Quantisation"..........................................................................................................................................."6" Acquiring"Colour"Images"........................................................................................................................"6" Colour&Spac es Colour&Spaces es&&............................................................................................................................... ...............................................................................................................................& " &7 RGB"........................................................................................................................................................."7 " Greyscale"................................................................................................................................................"7 " HSV"........................................................................................................................................................."7" CMYK"......................................................................................................................................................"7" YUV"........................................................................................................................................................."7" Colour"Conversion".................................................................................................................................."7" RGB$à $Greyscale$...............................................................................................................................$7" RGB$à $HSV$........................................................................................................................................$7" CMYK$à $RGB$.....................................................................................................................................$7" RGB$à $YUV$........................................................................................................................................$7" ..................................................................................................................... .....................................................................................................................& Intensity&Transforms&..................................................................................................................... " &8 Spatial"Filtering"......................................................................................................................................."8" Intensity"Transforms".............................................................................................................................."8" Negation"................................................................................................................................................."8" Dynamic"Range"......................................................................................................................................."8" Contrast"Stretching"................................................................................................................................"8" Piecewise"Linear"Intensity"Transforms"..................................................................................................."8" Grey"Level"Slicing"...................................................................................................................................."9 " Gamma"Correction"................................................................................................................................."9" Dyadic"Intensity"Transforms"..................................................................................................................."9" ............................................................................ 1" 0 ............................................................................ ............&&10 Spatial&Filtering&(Noise&and&Nosie&Reduction)&................................................................ Why?"...................................................................................................................................................."10" Image"Noise".........................................................................................................................................."10" Uniform$Noise$..................................................................................................................................$10" Gaussian$Noise$.................................................................................................................................$10" Noise"Reduction"..................................................................................................................................."10" Spatial"Filtering:"Convolution"..............................................................................................................."11" Gaussian"Filters"...................................................................................................................................."11" Discrete$Gaussian$Filters$..................................................................................................................$11" Separable"Filters"..................................................................................................................................."11" .......................................................................................&&12 Spatial&Filtering:&Non-Linear&Methods&....................................................................................... " Non-Linear"Filters"................................................................................................................................."12" Salt"and"Pepper"Noise".........................................................................................................................."12" Median"Filter"........................................................................................................................................"12" Anisotropic"Diffusion"............................................................................................................................"12" Bilateral"Filtering".................................................................................................................................."12"

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Choosing"a"Filter"..................................................................................................................................."12"

Derivative&Filters& ve&Filters&......................................................................................................................... .........................................................................................................................& Derivati ve&Filters& ......................................................................................................................... " &13 Unsharp"Masking".................................................................................................................................."13" Derivative"Filters"..................................................................................................................................13 " " 1st"Derivative"........................................................................................................................................"13" 2nd"Derivative"........................................................................................................................................"13" Image"Sharpening"using"Derivatives"....................................................................................................14 " " The"Laplacian"........................................................................................................................................"14" By$Convolution$.................................................................................................................................$14" 1st"Derivative"Filters".............................................................................................................................."14" ...............................................................................15 Thresholding&and&Binary&Image&Processing&............................................................................... &15 " Binarisation:"Thresholding"..................................................................................................................."15" Adaptive"Methods"................................................................................................................................"15" Otsu"Thresholding"................................................................................................................................"15" Unimodal"Thresholding"(Rosin’s"method)"............................................................................................"16" Local"Adaptive"Methods"......................................................................................................................."16" Connected"Components"......................................................................................................................."17" Edge&Detection&&........................................................................................................................... ...........................................................................................................................18 Edge&Detection " &18 The"Theory"...........................................................................................................................................18 " " Robert’s"Cross"Operator"......................................................................................................................."18" Sobel"vs"Roberts"..................................................................................................................................."18" Difference"of"Gaussians"........................................................................................................................"18" 1st"Derivative"vs"2nd"Derivative"Methods".............................................................................................."18" The"Canny"Operator"............................................................................................................................."18" Non-Maximal"Suppression"..................................................................................................................."18" Thresholding"with"Hysteresis"..............................................................................................................."19" Painterly"Rendering".............................................................................................................................."19" Stroke-scan$Conversion$....................................................................................................................$19" 20 Histogram&Processing& ................................................................................................................. Histogram&Processing&................................................................................................................. .................................................................................................................& " &20 Histogram"Equalisation"........................................................................................................................20 " " Local"Enhancement".............................................................................................................................."20" .................................................................................................."&21 21 Content-based&Image&Retrieval& ..................................................................................................& Content -based&Image&Retrieval&.................................................................................................. Text-based$Approach$.......................................................................................................................$21" Content-based"Approach"....................................................................................................................."21" Database$Structure$..........................................................................................................................$21" Colour"Histograms"................................................................................................................................"21" Common"Distance"Metrics"..................................................................................................................."21" Histogram"Intersection"........................................................................................................................."22" Ballard$and$Swain$............................................................................................................................$22" Object"Position"....................................................................................................................................."22" Region/object-based"Queries"..............................................................................................................."22" The"Histogram"Ratio"............................................................................................................................."23" Problems"..............................................................................................................................................23 " " Frequency&Domain&Processing&................................................................................................... ...................................................................................................&"&24 Frequency&Domain&Processing& ................................................................................................... Image"Transforms:"The"Idea"................................................................................................................."24" The"Fourier"Transform"........................................................................................................................."24" Image"Transforms"................................................................................................................................"24" In"2D"....................................................................................................................................................."25"

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Frequency"Domain"..............................................................................................................................."25" Frequency"Domain"Processing"............................................................................................................."25" Filtering"in"the"Frequency"Domain"......................................................................................................."25"

Compositing&................................................................................................................................ ................................................................................................................................& Compositing& ................................................................................................................................ " &26 Intelligent"Scissors"................................................................................................................................"26" LiveWire"Algorithm"(Dijkstra’s"algorithm)"............................................................................................"26" Cooling"................................................................................................................................................."27" Interactive"Dynamic"Training"...............................................................................................................27 " " Blending"..............................................................................................................................................."27" Alpha-blending/feathering$..............................................................................................................$27" Image&Compression&.................................................................................................................... ....................................................................................................................& Image&Compression& .................................................................................................................... " &28 Coding"Redundancy".............................................................................................................................."28" Variable$Length$Encoding$(i.e.$a$codebook)$.....................................................................................$28" Spatial"Redundancy".............................................................................................................................."28" Run-Length$Encoding$.......................................................................................................................$28" Psychovisual"Redundancy"...................................................................................................................."29" Fidelity$Criteria$.................................................................................................................................$29" Image"Compression"Models"................................................................................................................."30" Exploiting"Coding"Redundancy"............................................................................................................."30" Entropy$.............................................................................................................................................$30" ........................................................................................................."&31 GIF&and&JPEG&Compression&......................................................................................................... .........................................................................................................& Spatial"Redundancy:"Predictive"Coding"................................................................................................"31" Differential"Pulse-code"Modulation"(DPCM)"........................................................................................"31" Predictive"Coding"................................................................................................................................."31" Psychovisua...