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ContrastStretch Class

Contrast stretching filter.
Inheritance Hierarchy
SystemObject
  Accord.Imaging.FiltersBaseInPlacePartialFilter
    Accord.Imaging.FiltersContrastStretch

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

Constructors
  NameDescription
Public methodContrastStretch
Initializes a new instance of the ContrastStretch class.
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Properties
Methods
  NameDescription
Public methodApply(Bitmap)
Apply filter to an image.
(Inherited from BaseInPlacePartialFilter.)
Public methodApply(BitmapData)
Apply filter to an image.
(Inherited from BaseInPlacePartialFilter.)
Public methodApply(UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseInPlacePartialFilter.)
Public methodApply(UnmanagedImage, UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(Bitmap)
Apply filter to an image.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(BitmapData)
Apply filter to an image.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(UnmanagedImage)
Apply filter to an unmanaged image.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(Bitmap, Rectangle)
Apply filter to an image or its part.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(BitmapData, Rectangle)
Apply filter to an image or its part.
(Inherited from BaseInPlacePartialFilter.)
Public methodApplyInPlace(UnmanagedImage, Rectangle)
Apply filter to an unmanaged image or its part.
(Inherited from BaseInPlacePartialFilter.)
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 BaseInPlacePartialFilterProcessFilter(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

Contrast stretching (or as it is often called normalization) is a simple image enhancement technique that attempts to improve the contrast in an image by 'stretching' the range of intensity values it contains to span a desired range of values, e.g. the full range of pixel values that the image type concerned allows. It differs from the more sophisticated histogram equalization in that it can only apply a linear scaling function to the image pixel values.

The result of this filter may be achieved by using ImageStatistics class, which allows to get pixels' intensities histogram, and LevelsLinear filter, which does linear correction of pixel's intensities.

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

Sample usage:

// create filter
ContrastStretch filter = new ContrastStretch( );
// process image
filter.ApplyInPlace( sourceImage );

Source image:

Result image:

See Also