template<typename TInputImage, typename TOutputImage>
class itk::CannyEdgeDetectionImageFilter< TInputImage, TOutputImage >
This filter is an implementation of a Canny edge detector for scalar-valued images.
Based on John Canny's paper "A Computational Approach
to Edge Detection"(IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. PAMI-8, No.6, November 1986), there are four major steps used in the edge-detection scheme: (1) Smooth the input image with Gaussian filter. (2) Calculate the second directional derivatives of the smoothed image. (3) Non-Maximum Suppression: the zero-crossings of 2nd derivative are found, and the sign of third derivative is used to find the correct extrema. (4) The hysteresis thresholding is applied to the gradient magnitude (multiplied with zero-crossings) of the smoothed image to find and link edges.
- Inputs and Outputs
- The input to this filter should be a scalar, real-valued Itk image of arbitrary dimension. The output should also be a scalar, real-value Itk image of the same dimensionality.
- Parameters
- There are four parameters for this filter that control the sub-filters used by the algorithm.
- Variance and Maximum error are used in the Gaussian smoothing of the input image. See itkDiscreteGaussianImageFilter for information on these parameters.
- Threshold is the lowest allowed value in the output image. Its data type is the same as the data type of the output image. Any values below the Threshold level will be replaced with the OutsideValue parameter value, whose default is zero.
- Todo:
- Edge-linking will be added when an itk connected component labeling algorithm is available.
- See also
- DiscreteGaussianImageFilter
-
ZeroCrossingImageFilter
-
ThresholdImageFilter
Definition at line 88 of file itkCannyEdgeDetectionImageFilter.h.
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| CannyEdgeDetectionImageFilter () |
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void | GenerateData () override |
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void | PrintSelf (std::ostream &os, Indent indent) const override |
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virtual void | CallCopyInputRegionToOutputRegion (OutputImageRegionType &destRegion, const InputImageRegionType &srcRegion) |
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virtual void | CallCopyOutputRegionToInputRegion (InputImageRegionType &destRegion, const OutputImageRegionType &srcRegion) |
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void | GenerateInputRequestedRegion () override |
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| ImageToImageFilter () |
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void | PrintSelf (std::ostream &os, Indent indent) const override |
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void | VerifyInputInformation () const override |
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| ~ImageToImageFilter () override=default |
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virtual void | PushBackInput (const DataObject *input) |
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virtual void | PushFrontInput (const DataObject *input) |
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virtual void | AfterThreadedGenerateData () |
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virtual void | AllocateOutputs () |
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virtual void | BeforeThreadedGenerateData () |
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void | ClassicMultiThread (ThreadFunctionType callbackFunction) |
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void | GenerateData () override |
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virtual const ImageRegionSplitterBase * | GetImageRegionSplitter () const |
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| ImageSource () |
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void | PrintSelf (std::ostream &os, Indent indent) const override |
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virtual unsigned int | SplitRequestedRegion (unsigned int i, unsigned int pieces, OutputImageRegionType &splitRegion) |
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| ~ImageSource () override=default |
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virtual void | ThreadedGenerateData (const OutputImageRegionType ®ion, ThreadIdType threadId) |
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virtual void | DynamicThreadedGenerateData (const OutputImageRegionType &outputRegionForThread) |
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virtual bool | GetDynamicMultiThreading () const |
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virtual void | SetDynamicMultiThreading (bool _arg) |
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virtual void | DynamicMultiThreadingOn () |
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virtual void | AddInput (DataObject *input) |
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void | AddOptionalInputName (const DataObjectIdentifierType &) |
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void | AddOptionalInputName (const DataObjectIdentifierType &, DataObjectPointerArraySizeType idx) |
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virtual void | AddOutput (DataObject *output) |
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bool | AddRequiredInputName (const DataObjectIdentifierType &) |
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bool | AddRequiredInputName (const DataObjectIdentifierType &, DataObjectPointerArraySizeType idx) |
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virtual void | CacheInputReleaseDataFlags () |
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virtual void | GenerateData () |
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virtual void | GenerateInputRequestedRegion () |
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virtual void | GenerateOutputInformation () |
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virtual void | GenerateOutputRequestedRegion (DataObject *output) |
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DataObject * | GetInput (const DataObjectIdentifierType &key) |
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const DataObject * | GetInput (const DataObjectIdentifierType &key) const |
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virtual const DataObjectPointerArraySizeType & | GetNumberOfRequiredInputs () const |
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virtual const DataObjectPointerArraySizeType & | GetNumberOfRequiredOutputs () const |
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bool | IsIndexedInputName (const DataObjectIdentifierType &) const |
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bool | IsIndexedOutputName (const DataObjectIdentifierType &) const |
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bool | IsRequiredInputName (const DataObjectIdentifierType &) const |
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DataObjectPointerArraySizeType | MakeIndexFromInputName (const DataObjectIdentifierType &name) const |
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DataObjectPointerArraySizeType | MakeIndexFromOutputName (const DataObjectIdentifierType &name) const |
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DataObjectIdentifierType | MakeNameFromInputIndex (DataObjectPointerArraySizeType idx) const |
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DataObjectIdentifierType | MakeNameFromOutputIndex (DataObjectPointerArraySizeType idx) const |
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virtual void | PopBackInput () |
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virtual void | PopFrontInput () |
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void | PrintSelf (std::ostream &os, Indent indent) const override |
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| ProcessObject () |
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virtual void | PropagateResetPipeline () |
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virtual void | PushBackInput (const DataObject *input) |
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virtual void | PushFrontInput (const DataObject *input) |
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virtual void | ReleaseInputs () |
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virtual void | RemoveInput (const DataObjectIdentifierType &key) |
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virtual void | RemoveInput (DataObjectPointerArraySizeType) |
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virtual void | RemoveOutput (const DataObjectIdentifierType &key) |
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virtual void | RemoveOutput (DataObjectPointerArraySizeType idx) |
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bool | RemoveRequiredInputName (const DataObjectIdentifierType &) |
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virtual void | RestoreInputReleaseDataFlags () |
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virtual void | SetInput (const DataObjectIdentifierType &key, DataObject *input) |
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virtual void | SetNthInput (DataObjectPointerArraySizeType idx, DataObject *input) |
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virtual void | SetNthOutput (DataObjectPointerArraySizeType idx, DataObject *output) |
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void | SetNumberOfIndexedInputs (DataObjectPointerArraySizeType num) |
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void | SetNumberOfIndexedOutputs (DataObjectPointerArraySizeType num) |
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virtual void | SetNumberOfRequiredInputs (DataObjectPointerArraySizeType) |
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virtual void | SetNumberOfRequiredOutputs (DataObjectPointerArraySizeType _arg) |
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virtual void | SetOutput (const DataObjectIdentifierType &name, DataObject *output) |
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virtual void | SetPrimaryInput (DataObject *object) |
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virtual void | SetPrimaryOutput (DataObject *object) |
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void | SetRequiredInputNames (const NameArray &) |
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virtual void | VerifyInputInformation () const |
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virtual void | VerifyPreconditions () const |
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| ~ProcessObject () override |
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DataObject * | GetInput (DataObjectPointerArraySizeType idx) |
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const DataObject * | GetInput (DataObjectPointerArraySizeType idx) const |
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DataObject * | GetPrimaryInput () |
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const DataObject * | GetPrimaryInput () const |
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virtual void | SetPrimaryInputName (const DataObjectIdentifierType &key) |
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virtual const char * | GetPrimaryInputName () const |
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DataObject * | GetOutput (const DataObjectIdentifierType &key) |
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const DataObject * | GetOutput (const DataObjectIdentifierType &key) const |
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virtual void | SetPrimaryOutputName (const DataObjectIdentifierType &key) |
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virtual const char * | GetPrimaryOutputName () const |
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DataObject * | GetOutput (DataObjectPointerArraySizeType i) |
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const DataObject * | GetOutput (DataObjectPointerArraySizeType i) const |
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DataObject * | GetPrimaryOutput () |
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const DataObject * | GetPrimaryOutput () const |
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virtual bool | GetThreaderUpdateProgress () const |
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virtual void | ThreaderUpdateProgressOn () |
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virtual void | SetThreaderUpdateProgress (bool arg) |
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| Object () |
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bool | PrintObservers (std::ostream &os, Indent indent) const |
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void | PrintSelf (std::ostream &os, Indent indent) const override |
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virtual void | SetTimeStamp (const TimeStamp &timeStamp) |
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| ~Object () override |
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virtual LightObject::Pointer | InternalClone () const |
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| LightObject () |
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virtual void | PrintHeader (std::ostream &os, Indent indent) const |
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virtual void | PrintSelf (std::ostream &os, Indent indent) const |
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virtual void | PrintTrailer (std::ostream &os, Indent indent) const |
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virtual | ~LightObject () |
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