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AdaptiveSmoothing Class

Adaptive Smoothing - noise removal with edges preserving.
Inheritance Hierarchy
SystemObject
  Accord.Imaging.FiltersBaseUsingCopyPartialFilter
    Accord.Imaging.FiltersAdaptiveSmoothing

Namespace:  Accord.Imaging.Filters
Assembly:  Accord.Imaging (in Accord.Imaging.dll) Version: 3.7.0
Syntax
public class AdaptiveSmoothing : BaseUsingCopyPartialFilter
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The AdaptiveSmoothing type exposes the following members.

Constructors
  NameDescription
Public methodAdaptiveSmoothing
Initializes a new instance of the AdaptiveSmoothing class.
Public methodAdaptiveSmoothing(Double)
Initializes a new instance of the AdaptiveSmoothing class.
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Properties
Methods
  NameDescription
Public methodApply(Bitmap)
Apply filter to an image.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApply(BitmapData)
Apply filter to an image.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApply(UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApply(UnmanagedImage, UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(Bitmap)
Apply filter to an image.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(BitmapData)
Apply filter to an image.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(UnmanagedImage)
Apply filter to an unmanaged image.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(Bitmap, Rectangle)
Apply filter to an image or its part.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(BitmapData, Rectangle)
Apply filter to an image or its part.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodApplyInPlace(UnmanagedImage, Rectangle)
Apply filter to an unmanaged image or its part.
(Inherited from BaseUsingCopyPartialFilter.)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodProcessFilter
Process the filter on the specified image.
(Overrides BaseUsingCopyPartialFilterProcessFilter(UnmanagedImage, UnmanagedImage, Rectangle).)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Extension Methods
  NameDescription
Public Extension MethodHasMethod
Checks whether an object implements a method with the given name.
(Defined by ExtensionMethods.)
Public Extension MethodIsEqual
Compares two objects for equality, performing an elementwise comparison if the elements are vectors or matrices.
(Defined by Matrix.)
Public Extension MethodToT
Converts an object into another type, irrespective of whether the conversion can be done at compile time or not. This can be used to convert generic types to numeric types during runtime.
(Defined by ExtensionMethods.)
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Remarks

The filter is aimed to perform image smoothing, but keeping sharp edges. This makes it applicable to additive noise removal and smoothing objects' interiors, but not applicable for spikes (salt and pepper noise) removal.

The next calculations are done for each pixel:

  • weights are calculate for 9 pixels - pixel itself and 8 neighbors:
    w(x, y) = exp( -1 * (Gx^2 + Gy^2) / (2 * factor^2) )
    Gx(x, y) = (I(x + 1, y) - I(x - 1, y)) / 2
    Gy(x, y) = (I(x, y + 1) - I(x, y - 1)) / 2
    , where factor is a configurable value determining smoothing's quality.
  • sum of 9 weights is calclated (weightTotal);
  • sum of 9 weighted pixel values is calculatd (total);
  • destination pixel is calculated as total / weightTotal.

Description of the filter was found in "An Edge Detection Technique Using the Facet Model and Parameterized Relaxation Labeling" by Ioannis Matalas, Student Member, IEEE, Ralph Benjamin, and Richard Kitney.

The filter accepts 8 bpp grayscale images and 24 bpp color images for processing.

Sample usage:

// create filter
AdaptiveSmoothing filter = new AdaptiveSmoothing( );
// apply the filter
filter.ApplyInPlace( image );

Initial image:

Result image:

See Also