w2img::MorphEdgeFilter Class Reference

Inheritance diagram for w2img::MorphEdgeFilter:

w2img::ImageFilter w2img::SingleData2DFilter w2img::Data2DFilter List of all members.

Detailed Description

This filter finds edges based on rank differences (morphologic processing).

The underlying idea is to dilate and erode the original image and assume that locations of large differences between the two corresponds to edges. The filter works well where there is uniform additive noise.

Steven S. S. Poon, Rabab K. Ward: A Simple and Effective Filter Based on the Rank Difference. ICIP 2000

Author:
Lakshman
Version:
Id
w2img_MorphEdgeFilter.h,v 1.2 2009/06/02 20:17:57 lakshman Exp


Public Member Functions

 MorphEdgeFilter (double percentile_upper, double percentile_lower, int half_size_x, int half_size_y, float min_fill)
 specify the percentiles (upper and lower).
virtual ~MorphEdgeFilter ()
virtual code::Image< float > filterImage (const code::Image< float > &data)
 the work-horse function.
virtual code::SmartPtr< code::DataType > filter (const code::RadialSet &)
virtual code::SmartPtr< code::DataType > filter (const code::CartesianGrid2D &)
virtual code::SmartPtr< code::DataType > filter (const code::LatLonGrid &)
void process (code::PolarGrid &)
 Note that you need to call getResult() to get the result.
void process (code::RadialSet &)
 Note that you need to call getResult() to get the result.
void process (code::CartesianGrid2D &)
 Note that you need to call getResult() to get the result.
void process (code::LatLonGrid &)
 Note that you need to call getResult() to get the result.
void process (code::WindFieldStruct< code::LatLonGrid > &)
 Note that you need to call getResult() to get the result.
void process (code::WindFieldStruct< code::CartesianGrid2D > &)
 Note that you need to call getResult() to get the result.
void allowChangingMissingData (bool in)
 Should we filter at missing data values also, or not process missing values? By default, smoothing around a missing value might produce a value at that point in the result i.e.
bool canChangeMissing () const
void setToHandleRadialData (bool in)
 Pass in true if radial data should be filtered directly instead, of as is default, to convert to CartesianGrid before contouring.
void setCartesianGridResolutionRatio (double inres)
 changes the grid resolution of CartesianGrids created from RadialSets from that of the gate width.
void setCartesianGridDimension (const code::Length &indim)
 clips cartesian grids to this extent in the horizontal and vertical directions.
void setWrapAroundRadials (size_t numWrapAroundRadials)
 Normally, the RadialSet processing is done with no radial "wrapping".
size_t getWrapAroundRadials () const
code::SmartPtr< code::DataType > getResult ()
 get the result of the filtering -- returns 0 on error.
void reset ()

Protected Attributes

code::SmartPtr< code::DataType > myResult


Constructor & Destructor Documentation

w2img::MorphEdgeFilter::MorphEdgeFilter ( double  percentile_upper,
double  percentile_lower,
int  half_size_x,
int  half_size_y,
float  min_fill 
)

specify the percentiles (upper and lower).

The larger the difference, the thicker the edges. The smaller the difference, the greater the chance that weak edges will be missed. Typically, upper and lower should straddle 50. Percentile of 100 is the maximum, percentile of 0 is the minimum and percentile of 50 is the median.

halfSize of 1 means a 3x3 neighborhood. x is the first (azimuthal or latitude) direction.

minFill=0.33 is recommended.

virtual w2img::MorphEdgeFilter::~MorphEdgeFilter (  )  [virtual]


Member Function Documentation

void w2img::SingleData2DFilter::allowChangingMissingData ( bool  in  )  [inline, virtual, inherited]

Should we filter at missing data values also, or not process missing values? By default, smoothing around a missing value might produce a value at that point in the result i.e.

the bool is true.

Implements w2img::Data2DFilter.

bool w2img::SingleData2DFilter::canChangeMissing (  )  const [inline, virtual, inherited]

Implements w2img::Data2DFilter.

virtual code::SmartPtr<code::DataType> w2img::ImageFilter::filter ( const code::LatLonGrid &   )  [virtual, inherited]

Implements w2img::SingleData2DFilter.

Reimplemented in w2img::DistanceFilter.

virtual code::SmartPtr<code::DataType> w2img::ImageFilter::filter ( const code::CartesianGrid2D &   )  [virtual, inherited]

Implements w2img::SingleData2DFilter.

Reimplemented in w2img::DistanceFilter.

virtual code::SmartPtr<code::DataType> w2img::ImageFilter::filter ( const code::RadialSet &   )  [virtual, inherited]

Implements w2img::SingleData2DFilter.

Reimplemented in w2img::DistanceFilter.

virtual code::Image<float> w2img::MorphEdgeFilter::filterImage ( const code::Image< float > &  data  )  [virtual]

the work-horse function.

Implements w2img::ImageFilter.

code::SmartPtr<code::DataType> w2img::Data2DFilter::getResult (  )  [inline, inherited]

get the result of the filtering -- returns 0 on error.

This may or may not be the same data as passed in, for example process(RadialSet) may return a CartesianGrid.

size_t w2img::SingleData2DFilter::getWrapAroundRadials (  )  const [inline, virtual, inherited]

Implements w2img::Data2DFilter.

void w2img::SingleData2DFilter::process ( code::WindFieldStruct< code::CartesianGrid2D > &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::SingleData2DFilter::process ( code::WindFieldStruct< code::LatLonGrid > &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::SingleData2DFilter::process ( code::LatLonGrid &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::SingleData2DFilter::process ( code::CartesianGrid2D &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::SingleData2DFilter::process ( code::RadialSet &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::SingleData2DFilter::process ( code::PolarGrid &   )  [inherited]

Note that you need to call getResult() to get the result.

The input data is not changed.

void w2img::Data2DFilter::reset (  )  [inline, inherited]

void w2img::SingleData2DFilter::setCartesianGridDimension ( const code::Length &  indim  )  [inline, virtual, inherited]

clips cartesian grids to this extent in the horizontal and vertical directions.

(Removes the boundaries, keeping the image centered at the same spot).

by default, no such clipping is done. Pass in Length() to turn off clipping.

Implements w2img::Data2DFilter.

void w2img::SingleData2DFilter::setCartesianGridResolutionRatio ( double  inres  )  [inline, virtual, inherited]

changes the grid resolution of CartesianGrids created from RadialSets from that of the gate width.

For example, if the RadialSet's gate width is 1km, then if the ratio is 3, the CartesianGrid's resolution is 0.33km. If the input ratio is 0.33 then the grid resolution will be 3km.

Implements w2img::Data2DFilter.

void w2img::SingleData2DFilter::setToHandleRadialData ( bool  in  )  [inline, virtual, inherited]

Pass in true if radial data should be filtered directly instead, of as is default, to convert to CartesianGrid before contouring.

Implements w2img::Data2DFilter.

void w2img::SingleData2DFilter::setWrapAroundRadials ( size_t  numWrapAroundRadials  )  [inline, virtual, inherited]

Normally, the RadialSet processing is done with no radial "wrapping".

You can remove boundary effects in the azimuthal direction by calling this function with a value greater than zero.

When filtering with a 5x5 kernel, this class will automatically add 5 radials, do the filtering and then remove the extra five radials. In that case, the number of wraparound radials should be set to 5.

Implements w2img::Data2DFilter.


Member Data Documentation

code::SmartPtr<code::DataType> w2img::Data2DFilter::myResult [protected, inherited]


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