CannyEdgeDetector Class |
Namespace: Accord.Imaging.Filters
The CannyEdgeDetector type exposes the following members.
Name | Description | |
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CannyEdgeDetector |
Initializes a new instance of the CannyEdgeDetector class.
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CannyEdgeDetector(Byte, Byte) |
Initializes a new instance of the CannyEdgeDetector class.
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CannyEdgeDetector(Byte, Byte, Double) |
Initializes a new instance of the CannyEdgeDetector class.
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Name | Description | |
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FormatTranslations |
Format translations dictionary.
(Overrides BaseUsingCopyPartialFilterFormatTranslations.) | |
GaussianSigma |
Gaussian sigma.
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GaussianSize |
Gaussian size.
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HighThreshold |
High threshold.
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LowThreshold |
Low threshold.
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Name | Description | |
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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.) |
Name | Description | |
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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.) |
The filter searches for objects' edges by applying Canny edge detector. The implementation follows Bill Green's Canny edge detection tutorial.
Note |
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The implemented canny edge detector has one difference with the above linked algorithm. The difference is in hysteresis step, which is a bit simplified (getting faster as a result). On the hysteresis step each pixel is compared with two threshold values: HighThreshold and LowThreshold. If pixel's value is greater or equal to HighThreshold, then it is kept as edge pixel. If pixel's value is greater or equal to LowThreshold, then it is kept as edge pixel only if there is at least one neighbouring pixel (8 neighbours are checked) which has value greater or equal to HighThreshold; otherwise it is none edge pixel. In the case if pixel's value is less than LowThreshold, then it is marked as none edge immediately. |
The filter accepts 8 bpp grayscale images for processing.
Sample usage:
// create filter CannyEdgeDetector filter = new CannyEdgeDetector( ); // apply the filter filter.ApplyInPlace( image );
Initial image:
Result image: