public BufferedImage filter( BufferedImage src, BufferedImage dst ) {
        int width = src.getWidth();
        int height = src.getHeight();
		int type = src.getType();
		WritableRaster srcRaster = src.getRaster();

        if ( dst == null )
            dst = createCompatibleDestImage( src, null );
		WritableRaster dstRaster = dst.getRaster();

        setDimensions( width, height);

		int[] inPixels = new int[width];
        for ( int y = 0; y < height; y++ ) {
			// We try to avoid calling getRGB on images as it causes them to become unmanaged, causing horrible performance problems.
			if ( type == BufferedImage.TYPE_INT_ARGB ) {
				srcRaster.getDataElements( 0, y, width, 1, inPixels );
				for ( int x = 0; x < width; x++ )
					inPixels[x] = filterRGB( x, y, inPixels[x] );
				dstRaster.setDataElements( 0, y, width, 1, inPixels );
			} else {
				src.getRGB( 0, y, width, 1, inPixels, 0, width );
				for ( int x = 0; x < width; x++ )
					inPixels[x] = filterRGB( x, y, inPixels[x] );
				dst.setRGB( 0, y, width, 1, inPixels, 0, width );
			}
        }

        return dst;
    }
An abstract superclass for point filters. The interface is the same as the old RGBImageFilter.
tomighty-swing/src/main/java/com/jhlabs/image/PointFilter.java