integrate-dx.bsh

import ij.*;
import ij.process.*;

/**
 *
 */
float mean( FloatProcessor source, int first, int last )
{
	double sum = 0;
	
	for ( int i = first; i < last; ++i )
		sum += source.getf( i );
	
	return ( float )( sum / ( last - first ) );
}

/**
 * source and target are assumed to have identical dimensions.
 */
void integrateRow( FloatProcessor source, FloatProcessor target, int row )
{
	final int first = row * source.getWidth();
	final int last = first + source.getWidth();
	
	final float dxMean = mean( source, first, last );
	
	/* integrate */
	double x = 0;
	double xMean = 0;
	for ( int i = first; i < last; ++i )
	{
		final float dx = source.getf( i );
		x += dx - dxMean;
		target.setf( i, ( float )x );
		xMean += x;
	}
	xMean /= last - first;
	
	/* normalize */
	for ( int i = first; i < last; ++i )
		target.setf( i, target.getf( i ) - ( float )xMean );	
}

ImagePlus impSource = IJ.getImage();
FloatProcessor source = impSource.getProcessor().convertToFloat();
FloatProcessor target = new FloatProcessor( source.getWidth(), source.getHeight() );
ImagePlus impTarget = new ImagePlus( "I " + impSource.getTitle(), target );
impTarget.show();

for ( int i = 0; i < source.getHeight(); ++i )
{
	integrateRow( source, target, i );
	impTarget.updateAndDraw();	
}