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BackwardQuadrilateralTransformation Class

Performs backward quadrilateral transformation into an area in destination image.
Inheritance Hierarchy
SystemObject
  Accord.Imaging.FiltersBaseInPlaceFilter
    Accord.Imaging.FiltersBackwardQuadrilateralTransformation

Namespace:  Accord.Imaging.Filters
Assembly:  Accord.Imaging (in Accord.Imaging.dll) Version: 3.6.0
Syntax
public class BackwardQuadrilateralTransformation : BaseInPlaceFilter
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The BackwardQuadrilateralTransformation type exposes the following members.

Constructors
Properties
  NameDescription
Public propertyDestinationQuadrilateral
Quadrilateral in destination image to transform into.
Public propertyFormatTranslations
Format translations dictionary.
(Overrides BaseInPlaceFilterFormatTranslations.)
Public propertySourceImage
Source image to be transformed into specified quadrilateral.
Public propertySourceUnmanagedImage
Source unmanaged image to be transformed into specified quadrilateral.
Public propertyUseInterpolation
Specifies if bilinear interpolation should be used or not.
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Methods
  NameDescription
Public methodApply(Bitmap)
Apply filter to an image.
(Inherited from BaseInPlaceFilter.)
Public methodApply(BitmapData)
Apply filter to an image.
(Inherited from BaseInPlaceFilter.)
Public methodApply(UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseInPlaceFilter.)
Public methodApply(UnmanagedImage, UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseInPlaceFilter.)
Public methodApplyInPlace(Bitmap)
Apply filter to an image.
(Inherited from BaseInPlaceFilter.)
Public methodApplyInPlace(BitmapData)
Apply filter to an image.
(Inherited from BaseInPlaceFilter.)
Public methodApplyInPlace(UnmanagedImage)
Apply filter to an unmanaged image.
(Inherited from BaseInPlaceFilter.)
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 BaseInPlaceFilterProcessFilter(UnmanagedImage).)
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

The class implements backward quadrilateral transformation algorithm, which allows to transform any rectangular image into any quadrilateral area in a given destination image. The idea of the algorithm is based on homogeneous transformation and its math is described by Paul Heckbert in his "Projective Mappings for Image Warping" paper.

The image processing routines implements similar math to QuadrilateralTransformation, but performs it in backward direction.

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

Sample usage:

// define quadrilateral's corners
List<IntPoint> corners = new List<IntPoint>( );
corners.Add( new IntPoint(  99,  99 ) );
corners.Add( new IntPoint( 156,  79 ) );
corners.Add( new IntPoint( 184, 126 ) );
corners.Add( new IntPoint( 122, 150 ) );
// create filter
BackwardQuadrilateralTransformation filter =
    new BackwardQuadrilateralTransformation( sourceImage, corners );
// apply the filter
Bitmap newImage = filter.Apply( image );

Source image:

Destination image:

Result image:

See Also