ITK Architecture

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ITKArchitecture
Kitware Inc.
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ITK Basics

• C Generic Programming
• Data Pipeline
• Multi-threading
• Streaming
• Exceptions
• Events / Observers
• Tcl, Python and Java wrapping

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Generic Programming
Example STL Standard Template Library
Abstraction of Types and Behaviors
stdvectorlt T gt
stdvectorlt int gt stdvectorlt double
gt stdvectorlt char gt stdvectorlt Point
gt stdvectorlt Image gt
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itkImage
itkImagelt PixelType , Dimension gt
itkImagelt char , 2 gt itkImagelt char , 3 gt
itkImagelt char , 4 gt itkImagelt float , 2 gt
itkImagelt RGB , 3 gt itkImagelt unsigned short
, 2 gt itkImagelt itkVectorltfloat,2gt , 2 gt
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namespaces
Avoid naming collisions
itk itkStatistics itkfem itkfemitpac
k itkbio
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Your favorite keyword
typedef
typedef itkImagelt char , 2 gt
ImageType typedef itkImageFilterlt ImageType ,
ImageType gt FilterType
otherwise... itkImageFilterlt Imagelt char , 2 gt
, Imagelt char , 2 gt gt
FilterType
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Smart Pointers
Object
counter0
counter1
counter2
counter3
Self - Delete
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SmartPointers
typedef itkImagelt char , 2 gt
ImageType typedef itkImageFilterlt ImageType ,
ImageType gt FilterType
FilterTypePointer filter FilterTypeNew() I
mageTypePointer image filter-gtGetOutput()
Pointer notation filter-gtUpdate()
NO NEED FOR filter-gtDelete()
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Const Correctness
Knowing constancy is Insight. Not knowing
constancy leads to disaster.
Tao Te Ching, XVI. Lao Tsu
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Const Smart Pointers
typedef itkImagelt char , 2 gt
ImageType typedef itkImageFilterlt ImageType ,
ImageType gt FilterType
FilterTypePointer filter FilterTypeNew() I
mageTypeConstPointer image filter-gtGetOutput()

Can only invoke const methods image-gtGetSpacing
()
Compiler error for non-const methods image-gtSetS
pacing ( spacing )
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Creating an Image
typedef itkImagelt char , 3 gt
ImageType ImageTypePointer image
ImageTypeNew() ImageTypeSizeType
size size 0 512 // x direction size 1
512 // y direction size 2 50 // z
direction ImageTypeIndexType start start 0
0 // x direction start 1 0 // y
direction start 2 0 // z direction
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Creating an Image
ImageTypeRegionType region region.SetSize(
size ) region.SetIndex( start ) image-gtSetRegio
ns( region ) image-gtAllocate() image-gtFillBuffer
( 0 ) ImageTypeSpacingType spacing spacing
0 0.83 // x direction spacing 1 0.83
// y direction spacing 2 2.15 // z
direction image-gtSetSpacing( spacing )
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Exercise 3
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Streaming
Processing Large Images
Output Image
Input Image
Filter
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Image Regions
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Data Pipeline
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Simple Image IO
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Simple Image IO
Loadable Factories
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Simple Image IO
include itkImage.h include itkImageFileReader
.h include itkImageFileWriter.h typedef
itkImagelt char , 2 gt ImageType typedef
itkImageFileReaderlt ImageType gt
ReaderType typedef itkImageFileWriterlt
ImageType gt WriterType ReaderTypePointer
reader ReaderTypeNew() WriterTypePointer
writer WriterTypeNew() reader-gtSetFileName
( inputImage.dcm ) // DICOM writer-gtSetFi
leName( outputImage.hdr ) //
Analyze writer-gtSetInput( reader-gtGetOutput()
) writer-gtUpdate()
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Exceptions
Error Management
Application Layer
ITK Layer
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Exceptions
try filter-gtUpdate()
catch( itkExceptionObject exp )
stdcerr ltlt exp ltlt stdendl
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Exercise 4
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Events and Observers
ItkObject
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Events and Observers
Common Events AnyEvent() StartEvent() EndEvent
() ProgressEvent() IterationEvent()
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Events and Observers
Execute()
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Events and Observers
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Exercise 5
ProgressEvent()
StartEvent()
EndEvent()
Execute()
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GUI Communication
GUI Layer
ITK Layer
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Enjoy ITK !