DifferenceOfGaussians Class

Difference of Gaussians filter.

Inheritance Hierarchy

SystemObject
Accord.Imaging.FiltersBaseInPlaceFilter
Accord.Imaging.FiltersDifferenceOfGaussians

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

Syntax

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public class DifferenceOfGaussians : BaseInPlaceFilter

Public Class DifferenceOfGaussians
	Inherits BaseInPlaceFilter

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The DifferenceOfGaussians type exposes the following members.

Constructors

	Name	Description
	DifferenceOfGaussians	Initializes a new instance of the DifferenceOfGaussians class.
	DifferenceOfGaussians(Int32, Int32)	Initializes a new instance of the DifferenceOfGaussians class.
	DifferenceOfGaussians(Int32, Int32, Double)	Initializes a new instance of the DifferenceOfGaussians class.
	DifferenceOfGaussians(Int32, Int32, Double, Double)	Initializes a new instance of the DifferenceOfGaussians class.

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Properties

	Name	Description
	First	Gets or sets the first Gaussian filter.
	FormatTranslations	Format translations dictionary. (Overrides BaseInPlaceFilterFormatTranslations.)
	Second	Gets or sets the second Gaussian filter.
	Subtract	Gets or sets the subtract filter used to compute the difference of the two Gaussian blurs.

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Methods

	Name	Description
	Apply(Bitmap)	Apply filter to an image. (Inherited from BaseInPlaceFilter.)
	Apply(BitmapData)	Apply filter to an image. (Inherited from BaseInPlaceFilter.)
	Apply(UnmanagedImage)	Apply filter to an image in unmanaged memory. (Inherited from BaseInPlaceFilter.)
	Apply(UnmanagedImage, UnmanagedImage)	Apply filter to an image in unmanaged memory. (Inherited from BaseInPlaceFilter.)
	ApplyInPlace(Bitmap)	Apply filter to an image. (Inherited from BaseInPlaceFilter.)
	ApplyInPlace(BitmapData)	Apply filter to an image. (Inherited from BaseInPlaceFilter.)
	ApplyInPlace(UnmanagedImage)	Apply filter to an unmanaged image. (Inherited from BaseInPlaceFilter.)
	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 BaseInPlaceFilterProcessFilter(UnmanagedImage).)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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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.)

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Remarks

In imaging science, the difference of Gaussians is a feature enhancement algorithm that involves the subtraction of one blurred version of an original image from another, less blurred version of the original.

In the simple case of grayscale images, the blurred images are obtained by convolving the original grayscale images with Gaussian kernels having differing standard deviations. Blurring an image using a Gaussian kernel suppresses only high-frequency spatial information. Subtracting one image from the other preserves spatial information that lies between the range of frequencies that are preserved in the two blurred images. Thus, the difference of Gaussians is a band-pass filter that discards all but a handful of spatial frequencies that are present in the original grayscale image.

This filter implementation has been contributed by Diego Catalano.

References:

Wikipedia contributors. "Difference of Gaussians." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 1 Jun. 2013. Web. 10 Feb. 2014.

Examples

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Bitmap image = ... // Lena's famous picture

// Create a new Difference of Gaussians
var DoG = new DifferenceOfGaussians();

// Apply the filter
Bitmap result = DoG.Apply(image);

// Show on the screen
ImageBox.Show(result);

The resulting image is shown below.

Reference

Accord.Imaging.Filters Namespace