com.sun.javafx.iio.common

Class SmoothMinifier

java.lang.Object

com.sun.javafx.iio.common.SmoothMinifier

All Implemented Interfaces:

PushbroomScaler

public class SmoothMinifier
extends java.lang.Object
implements PushbroomScaler

A class which implements smooth downscaling for sources acquired line-by-line. Source scanlines are pushed into the algorithm one at a time in sequence from the top to the bottom of the source image. The destination is also populated in line-by-line fashion as soon as enough source lines are available to calculate a given line. The class is used as follows:

 SmoothMinifier downscaler = new SmoothMinifier(sourceWidth, sourceHeight, numBands,
                                        destWidth, destHeight);
 for(int i = 0; i < sourceHeight; i++) {
     byte[] b = source.getLine(i);
     if (shrinker.putSourceScanline(b, 0)) {
         break;
     }
 }
 NIOBuffer destBuf = downscaler.getDestination();
 

The algorithm used calculates the destination sample in each band by averaging over a box centered on the backward mapped location of the destination pixel. The box has dimensions ceil(sourceWidth/destWidth) x ceil(sourceHeight/destHeight).

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	bottomPoints
protected int	boxHeight
protected java.nio.ByteBuffer	destBuf
protected int	destHeight
protected int	destLine
protected int	destWidth
protected int[]	leftPoints
protected int	numBands
protected int[]	rightPoints
protected double	scaleY
protected byte[][]	sourceData
protected int	sourceDataLine
protected int	sourceHeight
protected int	sourceLine
protected int	sourceWidth
protected int[]	tmpBuf
protected int[]	topPoints

Constructor Summary

Constructors

Constructor and Description
SmoothMinifier(int sourceWidth, int sourceHeight, int numBands, int destWidth, int destHeight) Instantiates a new SmoothMinifier object.

Method Summary

Modifier and Type	Method and Description
java.nio.ByteBuffer	getDestination() Retrieves the destination buffer.
boolean	putSourceScanline(byte[] scanline, int off) Push one scanline of source pixels into the downscaling engine.

Methods inherited from class java.lang.Object

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

Field Detail

sourceWidth

protected int sourceWidth

sourceHeight

protected int sourceHeight

numBands

protected int numBands

destWidth

protected int destWidth

destHeight

protected int destHeight

scaleY

protected double scaleY

destBuf

protected java.nio.ByteBuffer destBuf

boxHeight

protected int boxHeight

sourceData

protected byte[][] sourceData

leftPoints

protected int[] leftPoints

rightPoints

protected int[] rightPoints

topPoints

protected int[] topPoints

bottomPoints

protected int[] bottomPoints

sourceLine

protected int sourceLine

sourceDataLine

protected int sourceDataLine

destLine

protected int destLine

tmpBuf

protected int[] tmpBuf

Constructor Detail

SmoothMinifier

SmoothMinifier(int sourceWidth,
               int sourceHeight,
               int numBands,
               int destWidth,
               int destHeight)

Instantiates a new SmoothMinifier object.

Parameters:

sourceWidth - The source image width

sourceHeight - The source image height

numBands - The number of components per pixel in the images

destWidth - The destination image width

destHeight - The destination image height

Throws:

java.lang.IllegalArgumentException - if any of the parameters is non-positive or either destination dimension is greater than the corresponding source dimension.

Method Detail

getDestination

public java.nio.ByteBuffer getDestination()

Retrieves the destination buffer.

Specified by:

getDestination in interface PushbroomScaler

Returns:

The destination buffer.

putSourceScanline

public boolean putSourceScanline(byte[] scanline,
                                 int off)

Push one scanline of source pixels into the downscaling engine. A smooth downscaling algorithm is used.

Specified by:

putSourceScanline in interface PushbroomScaler

Parameters:

scanline - One scanline of source data.

off - The offline into the buffer.

Returns:

Whether the destination image is complete.

Throws:

java.lang.IllegalArgumentException - if off < 0.