package pl.wroc.pwr.imagechannel.moment;

import pl.wroc.pwr.basic.IDoubleOperator;
import pl.wroc.pwr.imagechannel.IImageChannel;

public class CentralMoment implements IDoubleOperator
{
	/**
	 *
	 */
	private static final long serialVersionUID = -3262209310121202780L;

	private IImageChannel imageChannel;

	private int p;
	private int q;

	public CentralMoment( IImageChannel imageChannel, int p, int q )
	{
		this.imageChannel = imageChannel;
		this.p = p;
		this.q = q;
	}

	public float applyDouble( )
	{
		float moment00 = new Moment( this.imageChannel, 0, 0 ).applyDouble( );
		float moment10 = new Moment( this.imageChannel, 1, 0 ).applyDouble( );
		float moment01 = new Moment( this.imageChannel, 0, 1 ).applyDouble( );

		float centroidX = moment10 / moment00;
		float centroidY = moment01 / moment00;

		float value = 0;

		for ( int x = 0; x < this.imageChannel.getXSize( ); x++ )
		{
			for ( int y = 0; y < this.imageChannel.getYSize( ); y++ )
			{
				value += Math.pow( x - centroidX, this.p ) * Math.pow( y - centroidY, this.q ) * this.imageChannel.getValue( x, y );
			}
		}
		return value;
	}

	public Float apply( )
	{
		return new Float( this.applyDouble( ) );
	}
}