org.ddogleg.solver

Class FitQuadratic3by3

java.lang.Object

org.ddogleg.solver.FitQuadratic3by3

public class FitQuadratic3by3
extends java.lang.Object

Fit observations to a 2D quadratic around a 3x3 region. Observations are specified in a local coordinate system with indexes from -1 to 1. Typically the maximum value is at the local center, (0,0) coordinate.

Even if the center pixel is the max value, it is still possible for peak to be found outside the 3x3 region. In that situation what happened is that it fit the points inside 3x3 region to one side of the curve. In many applications the estimate should then be ignored. If the minimum number of points was being considered then it would be impossible to go outside since it must pass through each sample point.

Constructor Summary

Constructors

Constructor and Description
FitQuadratic3by3()

Method Summary

Modifier and Type	Method and Description
double	getDeltaX()
double	getDeltaY()
void	process() Computes the maximum.
void	setValue(int index, double value) Sets the value by index.
void	setValue(int x, int y, double value) Sets the observed value by coordinate point.

Methods inherited from class java.lang.Object

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

Constructor Detail

FitQuadratic3by3

public FitQuadratic3by3()

Method Detail

setValue

public void setValue(int index,
                     double value)

Sets the value by index. A row-major matrix is used. index = (y+1)*3+x+1

Parameters:

index - Array index from 0 to 8

value - value at index

setValue

public void setValue(int x,
                     int y,
                     double value)

Sets the observed value by coordinate point.

Parameters:

x - x-coordinate.-1 to 1

y - y-coordinate -1 to 1

value - Observed value at that coordinate

process

public void process()

Computes the maximum.

getDeltaX

public double getDeltaX()

getDeltaY

public double getDeltaY()