org.openimaj.image.analysis.algorithm

Class SummedSqAreaTable

java.lang.Object

org.openimaj.image.analysis.algorithm.SummedSqAreaTable

All Implemented Interfaces:

ImageAnalyser<FImage>

Direct Known Subclasses:

SummedSqTiltAreaTable

public class SummedSqAreaTable
extends Object
implements ImageAnalyser<FImage>

Implementation of an Integral Image or Summed Area Table. This Implementation calculates both the sum and squared sum values.

See http://en.wikipedia.org/wiki/Summed_area_table and http://research.microsoft .com/en-us/um/people/viola/Pubs/Detect/violaJones_IJCV.pdf

Basically, this provides an efficient way to find the sum of all pixels in a rectangular area of an image.

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Field Summary

Fields

Modifier and Type	Field and Description
FImage	sqSum The squared sum data
FImage	sum The sum data

Constructor Summary

Constructors

Constructor and Description
SummedSqAreaTable() Construct an empty SAT
SummedSqAreaTable(FImage image) Construct a SAT from the provided image

Method Summary

Modifier and Type	Method and Description
void	analyseImage(FImage image) Analyse an image.
float	calculateSqSumArea(int x1, int y1, int x2, int y2) Calculate the sum of squared pixels in the image used for constructing this SAT within the rectangle defined by (x1,y1) [top-left coordinate] and (x2,y2) [bottom- right coordinate]
float	calculateSqSumArea(Rectangle r) Calculate the sum of squared pixels in the image used for constructing this SAT within the given rectangle
float	calculateSumArea(int x1, int y1, int x2, int y2) Calculate the sum of pixels in the image used for constructing this SAT within the rectangle defined by (x1,y1) [top-left coordinate] and (x2,y2) [bottom- right coordinate]
float	calculateSumArea(Rectangle r) Calculate the sum of pixels in the image used for constructing this SAT within the given rectangle
protected void	computeTable(FImage image)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sum

public FImage sum

The sum data

sqSum

public FImage sqSum

The squared sum data

Constructor Detail

SummedSqAreaTable

public SummedSqAreaTable()

Construct an empty SAT

SummedSqAreaTable

public SummedSqAreaTable(FImage image)

Construct a SAT from the provided image

Parameters:

image - the image

Method Detail

computeTable

protected void computeTable(FImage image)

calculateSumArea

public float calculateSumArea(int x1,
                              int y1,
                              int x2,
                              int y2)

Calculate the sum of pixels in the image used for constructing this SAT within the rectangle defined by (x1,y1) [top-left coordinate] and (x2,y2) [bottom- right coordinate]

Parameters:

x1 - x1

y1 - y1

x2 - x2

y2 - y2

Returns:

sum of pixels in given rectangle

calculateSumArea

public float calculateSumArea(Rectangle r)

Calculate the sum of pixels in the image used for constructing this SAT within the given rectangle

Parameters:

r - rectangle

Returns:

sum of pixels in given rectangle

calculateSqSumArea

public float calculateSqSumArea(int x1,
                                int y1,
                                int x2,
                                int y2)

Calculate the sum of squared pixels in the image used for constructing this SAT within the rectangle defined by (x1,y1) [top-left coordinate] and (x2,y2) [bottom- right coordinate]

Parameters:

x1 - x1

y1 - y1

x2 - x2

y2 - y2

Returns:

sum of pixels in given rectangle

calculateSqSumArea

public float calculateSqSumArea(Rectangle r)

Calculate the sum of squared pixels in the image used for constructing this SAT within the given rectangle

Parameters:

r - rectangle

Returns:

sum of pixels in given rectangle

analyseImage

public void analyseImage(FImage image)

Description copied from interface: ImageAnalyser

Analyse an image.

Specified by:

analyseImage in interface ImageAnalyser<FImage>

Parameters:

image - The image to process in place.