Module java.desktop
Package java.awt.image

# Class AffineTransformOp

java.lang.Object
java.awt.image.AffineTransformOp

All Implemented Interfaces:
  `BufferedImageOp`, `RasterOp`

public class AffineTransformOp extends Object implements BufferedImageOp, RasterOp
This class uses an affine transform to perform a linear mapping from 2D coordinates in the source image or `Raster` to 2D coordinates in the destination image or `Raster`. The type of interpolation that is used is specified through a constructor, either by a `RenderingHints` object or by one of the integer interpolation types defined in this class.

If a `RenderingHints` object is specified in the constructor, the interpolation hint and the rendering quality hint are used to set the interpolation type for this operation. The color rendering hint and the dithering hint can be used when color conversion is required.

Note that the following constraints have to be met:

- The source and destination must be different.
- For `Raster` objects, the number of bands in the source must be equal to the number of bands in the destination.

See Also:
  - `AffineTransform`
  - `BufferedImageFilter`
  - `RenderingHints.KEY_INTERPOLATION`
  - `RenderingHints.KEY_RENDERING`
  - `RenderingHints.KEY_COLOR_RENDERING`
  - `RenderingHints.KEY_DITHERING`

## Field Summary

Fields
Modifier and Type
Field
Description
`static final int`
`TYPE_BICUBIC`
Bicubic interpolation type.
`static final int`
`TYPE_BILINEAR`
Bilinear interpolation type.
`static final int`
`TYPE_NEAREST_NEIGHBOR`
Nearest-neighbor interpolation type.

## Constructor Summary

Constructors
Constructor
Description
`AffineTransformOp(AffineTransform xform, int interpolationType)`
Constructs an `AffineTransformOp` given an affine transform and the interpolation type.
`AffineTransformOp(AffineTransform xform, RenderingHints hints)`
Constructs an `AffineTransformOp` given an affine transform.

## Method Summary

Modifier and Type
Method
Description
`BufferedImage`
`createCompatibleDestImage(BufferedImage src, ColorModel destCM)`
Creates a zeroed destination image with the correct size and number of bands.
`WritableRaster`
`createCompatibleDestRaster(Raster src)`
Creates a zeroed destination `Raster` with the correct size and number of bands.
`final BufferedImage`
`filter(BufferedImage src, BufferedImage dst)`
Transforms the source `BufferedImage` and stores the results in the destination `BufferedImage`.
`final WritableRaster`
`filter(Raster src, WritableRaster dst)`
Transforms the source `Raster` and stores the results in the destination `Raster`.
`final Rectangle2D`
`getBounds2D(BufferedImage src)`
Returns the bounding box of the transformed destination.
`final Rectangle2D`
`getBounds2D(Raster src)`
Returns the bounding box of the transformed destination.
`final int`
`getInterpolationType()`
Returns the interpolation type used by this op.
`final Point2D`
`getPoint2D(Point2D srcPt, Point2D dstPt)`
Returns the location of the corresponding destination point given a point in the source.
`final RenderingHints`
`getRenderingHints()`
Returns the rendering hints used by this transform operation.
`final AffineTransform`
`getTransform()`
Returns the affine transform used by this transform operation.

### Methods declared in class java.lang.Object

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

## Field Details

### TYPE_NEAREST_NEIGHBOR

@Native public static final int TYPE_NEAREST_NEIGHBOR
Nearest-neighbor interpolation type.

See Also:
  - Constant Field Values

### TYPE_BILINEAR

@Native public static final int TYPE_BILINEAR
Bilinear interpolation type.

See Also:
  - Constant Field Values

### TYPE_BICUBIC

@Native public static final int TYPE_BICUBIC
Bicubic interpolation type.

See Also:
  - Constant Field Values

## Constructor Details

### AffineTransformOp

public AffineTransformOp(AffineTransform xform, RenderingHints hints)
Constructs an `AffineTransformOp` given an affine transform. The interpolation type is determined from the `RenderingHints` object. If the interpolation hint is defined, it will be used. Otherwise, if the rendering quality hint is defined, the interpolation type is determined from its value. If no hints are specified (`hints` is null), the interpolation type is `TYPE_NEAREST_NEIGHBOR`.

Parameters:
  `xform` - The `AffineTransform` to use for the operation.
  `hints` - The `RenderingHints` object used to specify the interpolation type for the operation.
Throws:
  `ImagingOpException` - if the transform is non-invertible.
See Also:
  - `RenderingHints.KEY_INTERPOLATION`
  - `RenderingHints.KEY_RENDERING`

### AffineTransformOp

public AffineTransformOp(AffineTransform xform, int interpolationType)
Constructs an `AffineTransformOp` given an affine transform and the interpolation type.

Parameters:
  `xform` - The `AffineTransform` to use for the operation.
  `interpolationType` - One of the integer interpolation type constants defined by this class: `TYPE_NEAREST_NEIGHBOR`, `TYPE_BILINEAR`, `TYPE_BICUBIC`.
Throws:
  `ImagingOpException` - if the transform is non-invertible.

## Method Details

### getInterpolationType

public final int getInterpolationType()
Returns the interpolation type used by this op.

Returns:
  the interpolation type.
See Also:
  - `TYPE_NEAREST_NEIGHBOR`
  - `TYPE_BILINEAR`
  - `TYPE_BICUBIC`

### filter

public final BufferedImage filter(BufferedImage src, BufferedImage dst)
Transforms the source `BufferedImage` and stores the results in the destination `BufferedImage`. If the color models for the two images do not match, a color conversion into the destination color model is performed. If the destination image is null, a `BufferedImage` is created with the source `ColorModel`.

The coordinates of the rectangle returned by `getBounds2D(BufferedImage)` are not necessarily the same as the coordinates of the `BufferedImage` returned by this method. If the upper-left corner coordinates of the rectangle are negative then this part of the rectangle is not drawn. If the upper-left corner coordinates of the rectangle are positive then the filtered image is drawn at that position in the destination `BufferedImage`.

An `IllegalArgumentException` is thrown if the source is the same as the destination.

Specified by:
  `filter` in interface `BufferedImageOp`
Parameters:
  `src` - The `BufferedImage` to transform.
  `dst` - The `BufferedImage` in which to store the results of the transformation.
Returns:
  The filtered `BufferedImage`.
Throws:
  `IllegalArgumentException` - if `src` and `dst` are the same
  `ImagingOpException` - if the image cannot be transformed because of a data-processing error that might be caused by an invalid image format, tile format, or image-processing operation, or any other unsupported operation.

### filter

public final WritableRaster filter(Raster src, WritableRaster dst)
Transforms the source `Raster` and stores the results in the destination `Raster`. This operation performs the transform band by band.

If the destination `Raster` is null, a new `Raster` is created. An `IllegalArgumentException` may be thrown if the source is the same as the destination or if the number of bands in the source is not equal to the number of bands in the destination.

The coordinates of the rectangle returned by `getBounds2D(Raster)` are not necessarily the same as the coordinates of the `WritableRaster` returned by this method. If the upper-left corner coordinates of rectangle are negative then this part of the rectangle is not drawn. If the coordinates of the rectangle are positive then the filtered image is drawn at that position in the destination `Raster`.

Specified by:
  `filter` in interface `RasterOp`
Parameters:
  `src` - The `Raster` to transform.
  `dst` - The `Raster` in which to store the results of the transformation.
Returns:
  The transformed `Raster`.
Throws:
  `ImagingOpException` - if the raster cannot be transformed because of a data-processing error that might be caused by an invalid image format, tile format, or image-processing operation, or any other unsupported operation.

### getBounds2D

public final Rectangle2D getBounds2D(BufferedImage src)
Returns the bounding box of the transformed destination. The rectangle returned is the actual bounding box of the transformed points. The coordinates of the upper-left corner of the returned rectangle might not be (0, 0).

Specified by:
  `getBounds2D` in interface `BufferedImageOp`
Parameters:
  `src` - The `BufferedImage` to be transformed.
Returns:
  The `Rectangle2D` representing the destination's bounding box.

### getBounds2D

public final Rectangle2D getBounds2D(Raster src)
Returns the bounding box of the transformed destination. The rectangle returned will be the actual bounding box of the transformed points. The coordinates of the upper-left corner of the returned rectangle might not be (0, 0).

Specified by:
  `getBounds2D` in interface `RasterOp`
Parameters:
  `src` - The `Raster` to be transformed.
Returns:
  The `Rectangle2D` representing the destination's bounding box.

### createCompatibleDestImage

public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel destCM)
Creates a zeroed destination image with the correct size and number of bands. A `RasterFormatException` may be thrown if the transformed width or height is equal to 0.

If `destCM` is null, an appropriate `ColorModel` is used; this `ColorModel` may have an alpha channel even if the source `ColorModel` is opaque.

Specified by:
  `createCompatibleDestImage` in interface `BufferedImageOp`
Parameters:
  `src` - The `BufferedImage` to be transformed.
  `destCM` - `ColorModel` of the destination. If null, an appropriate `ColorModel` is used.
Returns:
  The zeroed destination image.

### createCompatibleDestRaster

public WritableRaster createCompatibleDestRaster(Raster src)
Creates a zeroed destination `Raster` with the correct size and number of bands. A `RasterFormatException` may be thrown if the transformed width or height is equal to 0.

Specified by:
  `createCompatibleDestRaster` in interface `RasterOp`
Parameters:
  `src` - The `Raster` to be transformed.
Returns:
  The zeroed destination `Raster`.

### getPoint2D

public final Point2D getPoint2D(Point2D srcPt, Point2D dstPt)
Returns the location of the corresponding destination point given a point in the source. If `dstPt` is specified, it is used to hold the return value.

Specified by:
  `getPoint2D` in interface `BufferedImageOp`
Specified by:
  `getPoint2D` in interface `RasterOp`
Parameters:
  `srcPt` - The `Point2D` that represents the source point.
  `dstPt` - The `Point2D` in which to store the result.
Returns:
  The `Point2D` in the destination that corresponds to the specified point in the source.

### getTransform

public final AffineTransform getTransform()
Returns the affine transform used by this transform operation.

Returns:
  The `AffineTransform` associated with this op.

### getRenderingHints

public final RenderingHints getRenderingHints()
Returns the rendering hints used by this transform operation.

Specified by:
  `getRenderingHints` in interface `BufferedImageOp`
Specified by:
  `getRenderingHints` in interface `RasterOp`
Returns:
  The `RenderingHints` object associated with this op.