BilateralSmoothing Class

Bilateral filter implementation - edge preserving smoothing and noise reduction that uses chromatic and spatial factors.

Inheritance Hierarchy

SystemObject
Accord.Imaging.FiltersBaseUsingCopyPartialFilter
Accord.Imaging.FiltersBilateralSmoothing

Namespace: Accord.Imaging.Filters
Assembly: Accord.Imaging (in Accord.Imaging.dll) Version: 3.8.0

Syntax

Copy

public class BilateralSmoothing : BaseUsingCopyPartialFilter

Public Class BilateralSmoothing
	Inherits BaseUsingCopyPartialFilter

Request Example View Source

The BilateralSmoothing type exposes the following members.

Constructors

	Name	Description
	BilateralSmoothing	Initializes a new instance of the BilateralSmoothing class.

Top

Properties

	Name	Description
	ColorFactor	Determines the variance of color for a color domain, >= 1.
	ColorPower	Exponent power, used in Color function calculation, >= 1.
	EnableParallelProcessing	Enable or not parallel processing on multi-core CPUs.
	FormatTranslations	Format translations dictionary. (Overrides BaseUsingCopyPartialFilterFormatTranslations.)
	KernelSize	Size of a square for limiting surrounding pixels that take part in calculations, [3, 255].
	LimitKernelSize	Specifies if exception must be thrown in the case a large kernel size is used which may lead to significant performance issues.
	SpatialFactor	Determines smoothing power within a color domain (neighbor pixels of similar color), >= 1.
	SpatialPower	Exponent power, used in Spatial function calculation, >= 1.

Top

Methods

	Name	Description
	Apply(Bitmap)	Apply filter to an image. (Inherited from BaseUsingCopyPartialFilter.)
	Apply(BitmapData)	Apply filter to an image. (Inherited from BaseUsingCopyPartialFilter.)
	Apply(UnmanagedImage)	Apply filter to an image in unmanaged memory. (Inherited from BaseUsingCopyPartialFilter.)
	Apply(UnmanagedImage, UnmanagedImage)	Apply filter to an image in unmanaged memory. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(Bitmap)	Apply filter to an image. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(BitmapData)	Apply filter to an image. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(UnmanagedImage)	Apply filter to an unmanaged image. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(Bitmap, Rectangle)	Apply filter to an image or its part. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(BitmapData, Rectangle)	Apply filter to an image or its part. (Inherited from BaseUsingCopyPartialFilter.)
	ApplyInPlace(UnmanagedImage, Rectangle)	Apply filter to an unmanaged image or its part. (Inherited from BaseUsingCopyPartialFilter.)
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ProcessFilter	Process the filter on the specified image. (Overrides BaseUsingCopyPartialFilterProcessFilter(UnmanagedImage, UnmanagedImage, Rectangle).)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

Top

Extension Methods

	Name	Description
	HasMethod	Checks whether an object implements a method with the given name. (Defined by ExtensionMethods.)
	IsEqual	Compares two objects for equality, performing an elementwise comparison if the elements are vectors or matrices. (Defined by Matrix.)
	To(Type)	Overloaded. 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.)
	ToT	Overloaded. 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.)

Top

Remarks

Bilateral filter conducts "selective" Gaussian smoothing of areas of same color (domains) which removes noise and contrast artifacts while preserving sharp edges.

Two major parameters SpatialFactor and ColorFactor define the result of the filter. By changing these parameters you may achieve either only noise reduction with little change to the image or get nice looking effect to the entire image.

Although the filter can use parallel processing large KernelSize values (greater than 25) on high resolution images may decrease speed of processing. Also on high resolution images small KernelSize values (less than 9) may not provide noticeable results.

More details on the algorithm can be found by following this link.

The filter accepts 8 bpp grayscale images and 24/32 bpp color images for processing.

Sample usage:

Copy

// create filter
BilateralSmoothing filter = new BilateralSmoothing( );
filter.KernelSize    = 7;
filter.SpatialFactor = 10;
filter.ColorFactor   = 60;
filter.ColorPower    = 0.5;
// apply the filter
filter.ApplyInPlace( image );

Initial image:

Result image:

Reference

Accord.Imaging.Filters Namespace