ResampleOp (TwelveMonkeys :: Common

java.lang.Object
- com.twelvemonkeys.image.ResampleOp

All Implemented Interfaces:

BufferedImageOp
```
public class ResampleOp
extends Object
implements BufferedImageOp
```
Resamples (scales) a BufferedImage to a new width and height, using high performance and high quality algorithms. Several different interpolation algorithms may be specifed in the constructor, either using the filter type constants, or one of the RendereingHints.
For fastest results, use FILTER_POINT or FILTER_BOX. In most cases, FILTER_TRIANGLE will produce acceptable results, while being relatively fast. For higher quality output, use more sophisticated interpolation algorithms, like FILTER_MITCHELL or FILTER_LANCZOS.
Example:
```
 BufferedImage image;
 
 //...
 

 ResampleOp resampler = new ResampleOp(100, 100, ResampleOp.FILTER_TRIANGLE);
 BufferedImage thumbnail = resampler.filter(image, null);
 
```
If your imput image is very large, it's possible to first resample using the very fast FILTER_POINT algorithm, then resample to the wanted size, using a higher quality algorithm:
```
 BufferedImage verylLarge;
 
 //...
 

 int w = 300;
 int h = 200;
 

 BufferedImage temp = new ResampleOp(w * 2, h * 2, FILTER_POINT).filter(verylLarge, null);
 

 BufferedImage scaled = new ResampleOp(w, h).filter(temp, null);
 
```
For maximum performance, this class will use native code, through JMagick, when available. Otherwise, the class will silently fall back to pure Java mode. Native code may be disabled globally, by setting the system property com.twelvemonkeys.image.accel to false. To allow debug of the native code, set the system property com.twelvemonkeys.image.magick.debug to true.
This BufferedImageOp is based on C example code found in Graphics Gems III, Filtered Image Rescaling, by Dale Schumacher (with additional improvments by Ray Gardener). Additional changes are inspired by ImageMagick and Marco Schmidt's Java Imaging Utilities (which are also adaptions of the same original code from Graphics Gems III).
For a description of the various interpolation algorithms, see General Filtered Image Rescaling in Graphics Gems III, Academic Press, 1994.
Version:

$Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/image/ResampleOp.java#1 $

Author:

Harald Kuhr, last modified by $Author: haku $

See Also:
ResampleOp(int,int,int), ResampleOp(int,int,java.awt.RenderingHints), BufferedImage, RenderingHints, AffineTransformOp

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`FILTER_BLACKMAN` Blackman interpolation..
`static int`	`FILTER_BLACKMAN_BESSEL` Blackman-Bessel interpolation.
`static int`	`FILTER_BLACKMAN_SINC` Blackman-Sinc interpolation.
`static int`	`FILTER_BOX` Box interpolation.
`static int`	`FILTER_CATROM` Catrom interpolation.
`static int`	`FILTER_CUBIC` Cubic interpolation.
`static int`	`FILTER_GAUSSIAN` Gaussian interpolation.
`static int`	`FILTER_HAMMING` Hamming interpolation.
`static int`	`FILTER_HANNING` Hanning interpolation.
`static int`	`FILTER_HERMITE` Hermite interpolation.
`static int`	`FILTER_LANCZOS` Lanczos interpolation.
`static int`	`FILTER_MITCHELL` Mitchell interpolation.
`static int`	`FILTER_POINT` Point interpolation (also known as "nearest neighbour").
`static int`	`FILTER_QUADRATIC` Quadratic interpolation.
`static int`	`FILTER_TRIANGLE` Triangle interpolation (also known as "linear" or "bilinear").
`static int`	`FILTER_UNDEFINED` Undefined interpolation, filter method will use default filter.
`static RenderingHints.Key`	`KEY_RESAMPLE_INTERPOLATION` RenderingHints.Key specifying resampling interpolation algorithm.
`static Object`	`VALUE_INTERPOLATION_BLACKMAN`
`static Object`	`VALUE_INTERPOLATION_BLACKMAN_BESSEL`
`static Object`	`VALUE_INTERPOLATION_BLACKMAN_SINC`
`static Object`	`VALUE_INTERPOLATION_BOX`
`static Object`	`VALUE_INTERPOLATION_CATROM`
`static Object`	`VALUE_INTERPOLATION_CUBIC`
`static Object`	`VALUE_INTERPOLATION_GAUSSIAN`
`static Object`	`VALUE_INTERPOLATION_HAMMING`
`static Object`	`VALUE_INTERPOLATION_HANNING`
`static Object`	`VALUE_INTERPOLATION_HERMITE`
`static Object`	`VALUE_INTERPOLATION_LANCZOS`
`static Object`	`VALUE_INTERPOLATION_MITCHELL`
`static Object`	`VALUE_INTERPOLATION_POINT`
`static Object`	`VALUE_INTERPOLATION_QUADRATIC`
`static Object`	`VALUE_INTERPOLATION_TRIANGLE`

Constructor Summary

Constructors
Constructor and Description
`ResampleOp(int width, int height)` Creates a `ResampleOp` that will resample input images to the given width and height, using the default interpolation filter.
`ResampleOp(int width, int height, int filterType)` Creates a `ResampleOp` that will resample input images to the given width and height, using the given interpolation filter.
`ResampleOp(int width, int height, RenderingHints hints)` Creates a `ResampleOp` that will resample input images to the given width and height, using the interpolation filter specified by the given hints.

Method Summary

Methods
Modifier and Type	Method and Description
`BufferedImage`	`createCompatibleDestImage(BufferedImage pInput, ColorModel pModel)`
`BufferedImage`	`filter(BufferedImage input, BufferedImage output)` Re-samples (scales) the image to the size, and using the algorithm specified in the constructor.
`Rectangle2D`	`getBounds2D(BufferedImage src)`
`int`	`getFilterType()` Returns the current filter type constant.
`Point2D`	`getPoint2D(Point2D srcPt, Point2D dstPt)`
`RenderingHints`	`getRenderingHints()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - FILTER_UNDEFINED
```
public static final int FILTER_UNDEFINED
```
    Undefined interpolation, filter method will use default filter.
    
    See Also:
    Constant Field Values
  - FILTER_POINT
```
public static final int FILTER_POINT
```
    Point interpolation (also known as "nearest neighbour"). Very fast, but low quality (similar to RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR and Image.SCALE_REPLICATE).
    
    See Also:
    Constant Field Values
  - FILTER_BOX
```
public static final int FILTER_BOX
```
    Box interpolation. Fast, but low quality.
    
    See Also:
    Constant Field Values
  - FILTER_TRIANGLE
```
public static final int FILTER_TRIANGLE
```
    Triangle interpolation (also known as "linear" or "bilinear"). Quite fast, with acceptable quality (similar to RenderingHints.VALUE_INTERPOLATION_BILINEAR and Image.SCALE_AREA_AVERAGING).
    
    See Also:
    Constant Field Values
  - FILTER_HERMITE
```
public static final int FILTER_HERMITE
```
    Hermite interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_HANNING
```
public static final int FILTER_HANNING
```
    Hanning interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_HAMMING
```
public static final int FILTER_HAMMING
```
    Hamming interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_BLACKMAN
```
public static final int FILTER_BLACKMAN
```
    Blackman interpolation..
    
    See Also:
    Constant Field Values
  - FILTER_GAUSSIAN
```
public static final int FILTER_GAUSSIAN
```
    Gaussian interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_QUADRATIC
```
public static final int FILTER_QUADRATIC
```
    Quadratic interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_CUBIC
```
public static final int FILTER_CUBIC
```
    Cubic interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_CATROM
```
public static final int FILTER_CATROM
```
    Catrom interpolation.
    
    See Also:
    Constant Field Values
  - FILTER_MITCHELL
```
public static final int FILTER_MITCHELL
```
    Mitchell interpolation. High quality.
    
    See Also:
    Constant Field Values
  - FILTER_LANCZOS
```
public static final int FILTER_LANCZOS
```
    Lanczos interpolation. High quality.
    
    See Also:
    Constant Field Values
  - FILTER_BLACKMAN_BESSEL
```
public static final int FILTER_BLACKMAN_BESSEL
```
    Blackman-Bessel interpolation. High quality.
    
    See Also:
    Constant Field Values
  - FILTER_BLACKMAN_SINC
```
public static final int FILTER_BLACKMAN_SINC
```
    Blackman-Sinc interpolation. High quality.
    
    See Also:
    Constant Field Values
  - KEY_RESAMPLE_INTERPOLATION
```
public static final RenderingHints.Key KEY_RESAMPLE_INTERPOLATION
```
    RenderingHints.Key specifying resampling interpolation algorithm.
  - VALUE_INTERPOLATION_POINT
```
public static final Object VALUE_INTERPOLATION_POINT
```
    See Also:
    FILTER_POINT
  - VALUE_INTERPOLATION_BOX
```
public static final Object VALUE_INTERPOLATION_BOX
```
    See Also:
    FILTER_BOX
  - VALUE_INTERPOLATION_TRIANGLE
```
public static final Object VALUE_INTERPOLATION_TRIANGLE
```
    See Also:
    FILTER_TRIANGLE
  - VALUE_INTERPOLATION_HERMITE
```
public static final Object VALUE_INTERPOLATION_HERMITE
```
    See Also:
    FILTER_HERMITE
  - VALUE_INTERPOLATION_HANNING
```
public static final Object VALUE_INTERPOLATION_HANNING
```
    See Also:
    FILTER_HANNING
  - VALUE_INTERPOLATION_HAMMING
```
public static final Object VALUE_INTERPOLATION_HAMMING
```
    See Also:
    FILTER_HAMMING
  - VALUE_INTERPOLATION_BLACKMAN
```
public static final Object VALUE_INTERPOLATION_BLACKMAN
```
    See Also:
    FILTER_BLACKMAN
  - VALUE_INTERPOLATION_GAUSSIAN
```
public static final Object VALUE_INTERPOLATION_GAUSSIAN
```
    See Also:
    FILTER_GAUSSIAN
  - VALUE_INTERPOLATION_QUADRATIC
```
public static final Object VALUE_INTERPOLATION_QUADRATIC
```
    See Also:
    FILTER_QUADRATIC
  - VALUE_INTERPOLATION_CUBIC
```
public static final Object VALUE_INTERPOLATION_CUBIC
```
    See Also:
    FILTER_CUBIC
  - VALUE_INTERPOLATION_CATROM
```
public static final Object VALUE_INTERPOLATION_CATROM
```
    See Also:
    FILTER_CATROM
  - VALUE_INTERPOLATION_MITCHELL
```
public static final Object VALUE_INTERPOLATION_MITCHELL
```
    See Also:
    FILTER_MITCHELL
  - VALUE_INTERPOLATION_LANCZOS
```
public static final Object VALUE_INTERPOLATION_LANCZOS
```
    See Also:
    FILTER_LANCZOS
  - VALUE_INTERPOLATION_BLACKMAN_BESSEL
```
public static final Object VALUE_INTERPOLATION_BLACKMAN_BESSEL
```
    See Also:
    FILTER_BLACKMAN_BESSEL
  - VALUE_INTERPOLATION_BLACKMAN_SINC
```
public static final Object VALUE_INTERPOLATION_BLACKMAN_SINC
```
    See Also:
    FILTER_BLACKMAN_SINC
- Constructor Detail
  - ResampleOp
```
public ResampleOp(int width,
          int height)
```
    Creates a ResampleOp that will resample input images to the given width and height, using the default interpolation filter.
    
    Parameters:
    width - width of the re-sampled image
    height - height of the re-sampled image
  - ResampleOp
```
public ResampleOp(int width,
          int height,
          RenderingHints hints)
```
    Creates a ResampleOp that will resample input images to the given width and height, using the interpolation filter specified by the given hints. If using RenderingHints, the hints are mapped as follows:
    - KEY_RESAMPLE_INTERPOLATION takes precedence over any standard java.awt hints, and dictates interpolation directly, see RenderingHints constants.
    - KEY_INTERPOLATION takes precedence over other hints.
      
      RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR specifies FILTER_POINT
      
      RenderingHints.VALUE_INTERPOLATION_BILINEAR specifies FILTER_TRIANGLE
      
      RenderingHints.VALUE_INTERPOLATION_BICUBIC specifies FILTER_QUADRATIC
    - KEY_RENDERING or KEY_COLOR_RENDERING
      
      RenderingHints.VALUE_RENDER_SPEED specifies FILTER_POINT
      
      RenderingHints.VALUE_RENDER_QUALITY specifies FILTER_MITCHELL
    Other hints have no effect on this filter.
    Parameters:
    width - width of the re-sampled image
    height - height of the re-sampled image
    hints - rendering hints, affecting interpolation algorithm
    See Also:
    KEY_RESAMPLE_INTERPOLATION, RenderingHints.KEY_INTERPOLATION, RenderingHints.KEY_RENDERING, RenderingHints.KEY_COLOR_RENDERING
  - ResampleOp
```
public ResampleOp(int width,
          int height,
          int filterType)
```
    Creates a ResampleOp that will resample input images to the given width and height, using the given interpolation filter.
    
    Parameters:
    width - width of the re-sampled image
    height - height of the re-sampled image
    filterType - interpolation filter algorithm
    See Also:
    filter type constants
- Method Detail
  - filter
```
public final BufferedImage filter(BufferedImage input,
                   BufferedImage output)
```
    Re-samples (scales) the image to the size, and using the algorithm specified in the constructor.
    
    Specified by:
    
    filter in interface BufferedImageOp
    
    Parameters:
    input - The BufferedImage to be filtered
    output - The BufferedImage in which to store the resampled image
    
    Returns:
    The re-sampled BufferedImage.
    
    Throws:
    
    NullPointerException - if input is null
    
    IllegalArgumentException - if input == output.
    See Also:
    ResampleOp(int,int,int)
  - getFilterType
```
public int getFilterType()
```
    Returns the current filter type constant.
    
    Returns:
    the current filter type constant.
    See Also:
    filter type constants
  - createCompatibleDestImage
```
public final BufferedImage createCompatibleDestImage(BufferedImage pInput,
                                      ColorModel pModel)
```
    Specified by:
    
    createCompatibleDestImage in interface BufferedImageOp
  - getRenderingHints
```
public RenderingHints getRenderingHints()
```
    Specified by:
    
    getRenderingHints in interface BufferedImageOp
  - getBounds2D
```
public Rectangle2D getBounds2D(BufferedImage src)
```
    Specified by:
    
    getBounds2D in interface BufferedImageOp
  - getPoint2D
```
public Point2D getPoint2D(Point2D srcPt,
                 Point2D dstPt)
```
    Specified by:
    
    getPoint2D in interface BufferedImageOp

Class ResampleOp

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

FILTER_UNDEFINED

FILTER_POINT

FILTER_BOX

FILTER_TRIANGLE

FILTER_HERMITE

FILTER_HANNING

FILTER_HAMMING

FILTER_BLACKMAN

FILTER_GAUSSIAN

FILTER_QUADRATIC

FILTER_CUBIC

FILTER_CATROM

FILTER_MITCHELL

FILTER_LANCZOS

FILTER_BLACKMAN_BESSEL

FILTER_BLACKMAN_SINC

KEY_RESAMPLE_INTERPOLATION

VALUE_INTERPOLATION_POINT

VALUE_INTERPOLATION_BOX

VALUE_INTERPOLATION_TRIANGLE

VALUE_INTERPOLATION_HERMITE

VALUE_INTERPOLATION_HANNING

VALUE_INTERPOLATION_HAMMING

VALUE_INTERPOLATION_BLACKMAN

VALUE_INTERPOLATION_GAUSSIAN

VALUE_INTERPOLATION_QUADRATIC

VALUE_INTERPOLATION_CUBIC

VALUE_INTERPOLATION_CATROM

VALUE_INTERPOLATION_MITCHELL

VALUE_INTERPOLATION_LANCZOS

VALUE_INTERPOLATION_BLACKMAN_BESSEL

VALUE_INTERPOLATION_BLACKMAN_SINC

Constructor Detail

ResampleOp

ResampleOp

ResampleOp

Method Detail

filter

getFilterType

createCompatibleDestImage

getRenderingHints

getBounds2D

getPoint2D