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QuadrilateralTransformation Class

Performs quadrilateral transformation of an area in a given source image.
Inheritance Hierarchy
SystemObject
  Accord.Imaging.FiltersBaseTransformationFilter
    Accord.Imaging.FiltersQuadrilateralTransformation

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

Constructors
Properties
  NameDescription
Public propertyAutomaticSizeCalculaton
Automatic calculation of destination image or not.
Public propertyFormatTranslations
Format translations dictionary.
(Overrides BaseTransformationFilterFormatTranslations.)
Public propertyNewHeight
Height of the new transformed image.
Public propertyNewWidth
Width of the new transformed image.
Public propertySourceQuadrilateral
Quadrilateral's corners in source image.
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 BaseTransformationFilter.)
Public methodApply(BitmapData)
Apply filter to an image.
(Inherited from BaseTransformationFilter.)
Public methodApply(UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseTransformationFilter.)
Public methodApply(UnmanagedImage, UnmanagedImage)
Apply filter to an image in unmanaged memory.
(Inherited from BaseTransformationFilter.)
Protected methodCalculateNewImageSize
Calculates new image size.
(Overrides BaseTransformationFilterCalculateNewImageSize(UnmanagedImage).)
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 BaseTransformationFilterProcessFilter(UnmanagedImage, UnmanagedImage).)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Fields
  NameDescription
Protected fieldnewHeight
New image height.
Protected fieldnewWidth
New image width.
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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 quadrilateral transformation algorithm, which allows to transform any quadrilateral from a given source image to a rectangular 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 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
QuadrilateralTransformation filter =
    new QuadrilateralTransformation( corners, 200, 200 );
// apply the filter
Bitmap newImage = filter.Apply( image );

Initial image:

Result image:

See Also