C# Class Accord.Imaging.IntegralImage

Integral image.

The class implements integral image concept, which is described by Viola and Jones in: P. Viola and M. J. Jones, "Robust real-time face detection", Int. Journal of Computer Vision 57(2), pp. 137–154, 2004.

"An integral image I of an input image G is defined as the image in which the intensity at a pixel position is equal to the sum of the intensities of all the pixels above and to the left of that position in the original image."

The intensity at position (x, y) can be written as:

x y I(x,y) = SUM( SUM( G(i,j) ) ) i=0 j=0

The class uses 32-bit integers to represent integral image.

The class processes only grayscale (8 bpp indexed) images.

This class contains two versions of each method: safe and unsafe. Safe methods do checks of provided coordinates and ensure that these coordinates belong to the image, what makes these methods slower. Unsafe methods do not do coordinates' checks and rely that these coordinates belong to the image, what makes these methods faster.

Sample usage:

 // create integral image IntegralImage im = IntegralImage.FromBitmap( image ); // get pixels' mean value in the specified rectangle float mean = im.GetRectangleMean( 10, 10, 20, 30 )

Inheritance: ICloneable

ファイルを表示 Open project: accord-net/framework Class Usage Examples

Protected Properties

Property	Type	Description
integralImage	].uint[

Public Methods

Method	Description
Clone ( ) : object	Creates a new object that is a copy of the current instance.
FromBitmap ( Bitmap image ) : IntegralImage	Construct integral image from source grayscale image.
FromBitmap ( BitmapData imageData ) : IntegralImage	Construct integral image from source grayscale image.
FromBitmap ( UnmanagedImage image ) : IntegralImage	Construct integral image from source grayscale image.
GetHaarXWavelet ( int x, int y, int radius ) : int	Calculate horizontal (X) haar wavelet at the specified point. The method calculates horizontal wavelet, which is a difference of two horizontally adjacent boxes' sums, i.e. A-B. A is the sum of rectangle with coordinates (x, y-radius, x+radius-1, y+radius-1). B is the sum of rectangle with coordinates (x-radius, y-radius, x-1, y+radiys-1).
GetHaarYWavelet ( int x, int y, int radius ) : int	Calculate vertical (Y) haar wavelet at the specified point. The method calculates vertical wavelet, which is a difference of two vertical adjacent boxes' sums, i.e. A-B. A is the sum of rectangle with coordinates (x-radius, y, x+radius-1, y+radius-1). B is the sum of rectangle with coordinates (x-radius, y-radius, x+radius-1, y-1).
GetRectangleMean ( int x, int y, int radius ) : float	Calculate mean value of pixels in the specified rectangle. The method calculates mean value of pixels in square rectangle with odd width and height. In the case if it is required to calculate mean value of 3x3 rectangle, then it is required to specify its center and radius equal to 1.
GetRectangleMean ( int x1, int y1, int x2, int y2 ) : float	Calculate mean value of pixels in the specified rectangle. Both specified points are included into the calculation rectangle.
GetRectangleMeanUnsafe ( int x, int y, int radius ) : float	Calculate mean value of pixels in the specified rectangle without checking it's coordinates. The method calculates mean value of pixels in square rectangle with odd width and height. In the case if it is required to calculate mean value of 3x3 rectangle, then it is required to specify its center and radius equal to 1.
GetRectangleMeanUnsafe ( int x1, int y1, int x2, int y2 ) : float	Calculate mean value of pixels in the specified rectangle without checking it's coordinates. Both specified points are included into the calculation rectangle.
GetRectangleSum ( int x, int y, int radius ) : uint	Calculate sum of pixels in the specified rectangle. The method calculates sum of pixels in square rectangle with odd width and height. In the case if it is required to calculate sum of 3x3 rectangle, then it is required to specify its center and radius equal to 1.
GetRectangleSum ( int x1, int y1, int x2, int y2 ) : uint	Calculate sum of pixels in the specified rectangle. Both specified points are included into the calculation rectangle.
GetRectangleSumUnsafe ( int x, int y, int radius ) : uint	Calculate sum of pixels in the specified rectangle without checking it's coordinates. The method calculates sum of pixels in square rectangle with odd width and height. In the case if it is required to calculate sum of 3x3 rectangle, then it is required to specify its center and radius equal to 1.
GetRectangleSumUnsafe ( int x1, int y1, int x2, int y2 ) : uint	Calculate sum of pixels in the specified rectangle without checking it's coordinates. Both specified points are included into the calculation rectangle.

Protected Methods

Method	Description
IntegralImage ( int width, int height ) : System	Initializes a new instance of the IntegralImage class. The constractor is protected, what makes it imposible to instantiate this class directly. To create an instance of this class FromBitmap(Bitmap) or FromBitmap(BitmapData) method should be used.

Method Details

Clone() public method

Creates a new object that is a copy of the current instance.

public Clone ( ) : object
return	object

FromBitmap() public static method

Construct integral image from source grayscale image.

The source image has incorrect pixel format.

public static FromBitmap ( Bitmap image ) : IntegralImage
image	System.Drawing.Bitmap	Source grayscale image.
return	IntegralImage

FromBitmap() public static method

Construct integral image from source grayscale image.

The source image has incorrect pixel format.

public static FromBitmap ( BitmapData imageData ) : IntegralImage
imageData	System.Drawing.Imaging.BitmapData	Source image data.
return	IntegralImage

FromBitmap() public static method

Construct integral image from source grayscale image.

The source image has incorrect pixel format.

public static FromBitmap ( UnmanagedImage image ) : IntegralImage
image	UnmanagedImage	Source unmanaged image.
return	IntegralImage

GetHaarXWavelet() public method

Calculate horizontal (X) haar wavelet at the specified point.

The method calculates horizontal wavelet, which is a difference of two horizontally adjacent boxes' sums, i.e. A-B. A is the sum of rectangle with coordinates (x, y-radius, x+radius-1, y+radius-1). B is the sum of rectangle with coordinates (x-radius, y-radius, x-1, y+radiys-1).

public GetHaarXWavelet ( int x, int y, int radius ) : int
x	int	X coordinate of the point to calculate wavelet at.
y	int	Y coordinate of the point to calculate wavelet at.
radius	int	Wavelet size to calculate.
return	int

GetHaarYWavelet() public method

Calculate vertical (Y) haar wavelet at the specified point.

The method calculates vertical wavelet, which is a difference of two vertical adjacent boxes' sums, i.e. A-B. A is the sum of rectangle with coordinates (x-radius, y, x+radius-1, y+radius-1). B is the sum of rectangle with coordinates (x-radius, y-radius, x+radius-1, y-1).

public GetHaarYWavelet ( int x, int y, int radius ) : int
x	int	X coordinate of the point to calculate wavelet at.
y	int	Y coordinate of the point to calculate wavelet at.
radius	int	Wavelet size to calculate.
return	int

GetRectangleMean() public method

Calculate mean value of pixels in the specified rectangle.

The method calculates mean value of pixels in square rectangle with odd width and height. In the case if it is required to calculate mean value of 3x3 rectangle, then it is required to specify its center and radius equal to 1.

public GetRectangleMean ( int x, int y, int radius ) : float
x	int	X coordinate of central point of the rectangle.
y	int	Y coordinate of central point of the rectangle.
radius	int	Radius of the rectangle.
return	float

GetRectangleMean() public method

Calculate mean value of pixels in the specified rectangle.

Both specified points are included into the calculation rectangle.

public GetRectangleMean ( int x1, int y1, int x2, int y2 ) : float
x1	int	X coordinate of left-top rectangle's corner.
y1	int	Y coordinate of left-top rectangle's corner.
x2	int	X coordinate of right-bottom rectangle's corner.
y2	int	Y coordinate of right-bottom rectangle's corner.
return	float

GetRectangleMeanUnsafe() public method

Calculate mean value of pixels in the specified rectangle without checking it's coordinates.

public GetRectangleMeanUnsafe ( int x, int y, int radius ) : float
x	int	X coordinate of central point of the rectangle.
y	int	Y coordinate of central point of the rectangle.
radius	int	Radius of the rectangle.
return	float

GetRectangleMeanUnsafe() public method

Calculate mean value of pixels in the specified rectangle without checking it's coordinates.

Both specified points are included into the calculation rectangle.

public GetRectangleMeanUnsafe ( int x1, int y1, int x2, int y2 ) : float
x1	int	X coordinate of left-top rectangle's corner.
y1	int	Y coordinate of left-top rectangle's corner.
x2	int	X coordinate of right-bottom rectangle's corner.
y2	int	Y coordinate of right-bottom rectangle's corner.
return	float

GetRectangleSum() public method

Calculate sum of pixels in the specified rectangle.

The method calculates sum of pixels in square rectangle with odd width and height. In the case if it is required to calculate sum of 3x3 rectangle, then it is required to specify its center and radius equal to 1.

public GetRectangleSum ( int x, int y, int radius ) : uint
x	int	X coordinate of central point of the rectangle.
y	int	Y coordinate of central point of the rectangle.
radius	int	Radius of the rectangle.
return	uint

GetRectangleSum() public method

Calculate sum of pixels in the specified rectangle.

Both specified points are included into the calculation rectangle.

public GetRectangleSum ( int x1, int y1, int x2, int y2 ) : uint
x1	int	X coordinate of left-top rectangle's corner.
y1	int	Y coordinate of left-top rectangle's corner.
x2	int	X coordinate of right-bottom rectangle's corner.
y2	int	Y coordinate of right-bottom rectangle's corner.
return	uint

GetRectangleSumUnsafe() public method

Calculate sum of pixels in the specified rectangle without checking it's coordinates.

public GetRectangleSumUnsafe ( int x, int y, int radius ) : uint
x	int	X coordinate of central point of the rectangle.
y	int	Y coordinate of central point of the rectangle.
radius	int	Radius of the rectangle.
return	uint

GetRectangleSumUnsafe() public method

Calculate sum of pixels in the specified rectangle without checking it's coordinates.

Both specified points are included into the calculation rectangle.

public GetRectangleSumUnsafe ( int x1, int y1, int x2, int y2 ) : uint
x1	int	X coordinate of left-top rectangle's corner.
y1	int	Y coordinate of left-top rectangle's corner.
x2	int	X coordinate of right-bottom rectangle's corner.
y2	int	Y coordinate of right-bottom rectangle's corner.
return	uint

IntegralImage() protected method

Initializes a new instance of the IntegralImage class.

The constractor is protected, what makes it imposible to instantiate this class directly. To create an instance of this class FromBitmap(Bitmap) or FromBitmap(BitmapData) method should be used.

protected IntegralImage ( int width, int height ) : System
width	int	Image width.
height	int	Image height.
return	System

Property Details

integralImage protected_oe property

Intergral image's array.

See remarks to InternalData property.

protected uint[,] integralImage
return	].uint[