org.openimaj.image.analysis.algorithm

Class SummedAreaTable

java.lang.Object

org.openimaj.image.analysis.algorithm.SummedAreaTable

All Implemented Interfaces:

ImageAnalyser<FImage>

public class SummedAreaTable
extends Object
implements ImageAnalyser<FImage>

Implementation of an Integral Image or Summed Area Table.

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	data The SAT data

Constructor Summary

Constructors

Constructor and Description
SummedAreaTable() Construct an empty SAT
SummedAreaTable(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	calculateArea(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	calculateArea(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

data

public FImage data

The SAT data

Constructor Detail

SummedAreaTable

public SummedAreaTable()

Construct an empty SAT

SummedAreaTable

public SummedAreaTable(FImage image)

Construct a SAT from the provided image

Parameters:

image - the image

Method Detail

computeTable

protected void computeTable(FImage image)

calculateArea

public float calculateArea(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

calculateArea

public float calculateArea(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

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.