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BradleyLocalThresholding Class |
Adaptive thresholding using the internal image.
Inheritance HierarchyNamespace: Accord.Imaging.Filters
Assembly: Accord.Imaging (in Accord.Imaging.dll) Version: 3.8.0
SyntaxThe BradleyLocalThresholding type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | BradleyLocalThresholding |
Initializes a new instance of the BradleyLocalThresholding class.
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Properties| Name | Description | |
|---|---|---|
 | FormatTranslations |
Format translations dictionary.
(Overrides BaseInPlaceFilterFormatTranslations.) |
| PixelBrightnessDifferenceLimit |
Brightness difference limit between processing pixel and average value across neighbors.
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| WindowSize |
Window size to calculate average value of pixels for.
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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.) |
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.) |
RemarksThe image processing routine implements local thresholding technique described by Derek Bradley and Gerhard Roth in the "Adaptive Thresholding Using the Integral Image" paper.
The brief idea of the algorithm is that every image's pixel is set to black if its brightness is t percent lower (see PixelBrightnessDifferenceLimit) than the average brightness of surrounding pixels in the window of the specified size (see WindowSize), othwerwise it is set to white.
Sample usage:
// create the filter BradleyLocalThresholding filter = new BradleyLocalThresholding( ); // apply the filter filter.ApplyInPlace( image );
Initial image:
Result image:
See Also