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package java.awt.image;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import java.awt.geom.Rectangle2D;
import java.awt.geom.Point2D;
import java.awt.AlphaComposite;
import java.awt.GraphicsEnvironment;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.lang.annotation.Native;
import sun.awt.image.ImagingLib;
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:
/**
* This class uses an affine transform to perform a linear mapping from
* 2D coordinates in the source image or {@code Raster} to 2D coordinates
* in the destination image or {@code Raster}.
* The type of interpolation that is used is specified through a constructor,
* either by a {@code RenderingHints} object or by one of the integer
* interpolation types defined in this class.
* <p>
* If a {@code 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.
* <p>
* Note that the following constraints have to be met:
* <ul>
* <li>The source and destination must be different.
* <li>For {@code Raster} objects, the number of bands in the source must
* be equal to the number of bands in the destination.
* </ul>
* @see AffineTransform
* @see BufferedImageFilter
* @see java.awt.RenderingHints#KEY_INTERPOLATION
* @see java.awt.RenderingHints#KEY_RENDERING
* @see java.awt.RenderingHints#KEY_COLOR_RENDERING
* @see java.awt.RenderingHints#KEY_DITHERING
*/
public class AffineTransformOp implements BufferedImageOp, RasterOp {
private AffineTransform xform;
RenderingHints hints;
Nearest-neighbor interpolation type.
/**
* Nearest-neighbor interpolation type.
*/
@Native public static final int TYPE_NEAREST_NEIGHBOR = 1;
Bilinear interpolation type.
/**
* Bilinear interpolation type.
*/
@Native public static final int TYPE_BILINEAR = 2;
Bicubic interpolation type.
/**
* Bicubic interpolation type.
*/
@Native public static final int TYPE_BICUBIC = 3;
int interpolationType = TYPE_NEAREST_NEIGHBOR;
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
. Params: - 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:
/**
* Constructs an {@code AffineTransformOp} given an affine transform.
* The interpolation type is determined from the
* {@code 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 ({@code hints} is null),
* the interpolation type is {@link #TYPE_NEAREST_NEIGHBOR
* TYPE_NEAREST_NEIGHBOR}.
*
* @param xform The {@code AffineTransform} to use for the
* operation.
*
* @param hints The {@code RenderingHints} object used to specify
* the interpolation type for the operation.
*
* @throws ImagingOpException if the transform is non-invertible.
* @see java.awt.RenderingHints#KEY_INTERPOLATION
* @see java.awt.RenderingHints#KEY_RENDERING
*/
public AffineTransformOp(AffineTransform xform, RenderingHints hints){
validateTransform(xform);
this.xform = (AffineTransform) xform.clone();
this.hints = hints;
if (hints != null) {
Object value = hints.get(RenderingHints.KEY_INTERPOLATION);
if (value == null) {
value = hints.get(RenderingHints.KEY_RENDERING);
if (value == RenderingHints.VALUE_RENDER_SPEED) {
interpolationType = TYPE_NEAREST_NEIGHBOR;
}
else if (value == RenderingHints.VALUE_RENDER_QUALITY) {
interpolationType = TYPE_BILINEAR;
}
}
else if (value == RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR) {
interpolationType = TYPE_NEAREST_NEIGHBOR;
}
else if (value == RenderingHints.VALUE_INTERPOLATION_BILINEAR) {
interpolationType = TYPE_BILINEAR;
}
else if (value == RenderingHints.VALUE_INTERPOLATION_BICUBIC) {
interpolationType = TYPE_BICUBIC;
}
}
else {
interpolationType = TYPE_NEAREST_NEIGHBOR;
}
}
Constructs an AffineTransformOp
given an affine transform and the interpolation type. Params: - 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.
/**
* Constructs an {@code AffineTransformOp} given an affine transform
* and the interpolation type.
*
* @param xform The {@code AffineTransform} to use for the operation.
* @param interpolationType One of the integer
* interpolation type constants defined by this class:
* {@link #TYPE_NEAREST_NEIGHBOR TYPE_NEAREST_NEIGHBOR},
* {@link #TYPE_BILINEAR TYPE_BILINEAR},
* {@link #TYPE_BICUBIC TYPE_BICUBIC}.
* @throws ImagingOpException if the transform is non-invertible.
*/
public AffineTransformOp(AffineTransform xform, int interpolationType) {
validateTransform(xform);
this.xform = (AffineTransform)xform.clone();
switch(interpolationType) {
case TYPE_NEAREST_NEIGHBOR:
case TYPE_BILINEAR:
case TYPE_BICUBIC:
break;
default:
throw new IllegalArgumentException("Unknown interpolation type: "+
interpolationType);
}
this.interpolationType = interpolationType;
}
Returns the interpolation type used by this op.
See Also: Returns: the interpolation type.
/**
* Returns the interpolation type used by this op.
* @return the interpolation type.
* @see #TYPE_NEAREST_NEIGHBOR
* @see #TYPE_BILINEAR
* @see #TYPE_BICUBIC
*/
public final int getInterpolationType() {
return interpolationType;
}
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.
Params: - src – The
BufferedImage
to transform. - dst – The
BufferedImage
in which to store the results of the transformation.
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.
Returns: The filtered BufferedImage
.
/**
* Transforms the source {@code BufferedImage} and stores the results
* in the destination {@code 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 {@code BufferedImage} is created with the source
* {@code ColorModel}.
* <p>
* The coordinates of the rectangle returned by
* {@code getBounds2D(BufferedImage)}
* are not necessarily the same as the coordinates of the
* {@code 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 {@code BufferedImage}.
* <p>
* An {@code IllegalArgumentException} is thrown if the source is
* the same as the destination.
*
* @param src The {@code BufferedImage} to transform.
* @param dst The {@code BufferedImage} in which to store the results
* of the transformation.
*
* @return The filtered {@code BufferedImage}.
* @throws IllegalArgumentException if {@code src} and
* {@code dst} are the same
* @throws 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.
*/
public final BufferedImage filter(BufferedImage src, BufferedImage dst) {
if (src == null) {
throw new NullPointerException("src image is null");
}
if (src == dst) {
throw new IllegalArgumentException("src image cannot be the "+
"same as the dst image");
}
boolean needToConvert = false;
ColorModel srcCM = src.getColorModel();
ColorModel dstCM;
BufferedImage origDst = dst;
if (dst == null) {
dst = createCompatibleDestImage(src, null);
dstCM = srcCM;
origDst = dst;
}
else {
dstCM = dst.getColorModel();
if (srcCM.getColorSpace().getType() !=
dstCM.getColorSpace().getType())
{
int type = xform.getType();
boolean needTrans = ((type&
(AffineTransform.TYPE_MASK_ROTATION|
AffineTransform.TYPE_GENERAL_TRANSFORM))
!= 0);
if (! needTrans &&
type != AffineTransform.TYPE_TRANSLATION &&
type != AffineTransform.TYPE_IDENTITY)
{
double[] mtx = new double[4];
xform.getMatrix(mtx);
// Check out the matrix. A non-integral scale will force ARGB
// since the edge conditions can't be guaranteed.
needTrans = (mtx[0] != (int)mtx[0] || mtx[3] != (int)mtx[3]);
}
if (needTrans &&
srcCM.getTransparency() == Transparency.OPAQUE)
{
// Need to convert first
ColorConvertOp ccop = new ColorConvertOp(hints);
BufferedImage tmpSrc = null;
int sw = src.getWidth();
int sh = src.getHeight();
if (dstCM.getTransparency() == Transparency.OPAQUE) {
tmpSrc = new BufferedImage(sw, sh,
BufferedImage.TYPE_INT_ARGB);
}
else {
WritableRaster r =
dstCM.createCompatibleWritableRaster(sw, sh);
tmpSrc = new BufferedImage(dstCM, r,
dstCM.isAlphaPremultiplied(),
null);
}
src = ccop.filter(src, tmpSrc);
}
else {
needToConvert = true;
dst = createCompatibleDestImage(src, null);
}
}
}
if (interpolationType != TYPE_NEAREST_NEIGHBOR &&
dst.getColorModel() instanceof IndexColorModel) {
dst = new BufferedImage(dst.getWidth(), dst.getHeight(),
BufferedImage.TYPE_INT_ARGB);
}
if (ImagingLib.filter(this, src, dst) == null) {
throw new ImagingOpException ("Unable to transform src image");
}
if (needToConvert) {
ColorConvertOp ccop = new ColorConvertOp(hints);
ccop.filter(dst, origDst);
}
else if (origDst != dst) {
java.awt.Graphics2D g = origDst.createGraphics();
try {
g.setComposite(AlphaComposite.Src);
g.drawImage(dst, 0, 0, null);
} finally {
g.dispose();
}
}
return origDst;
}
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
.
Params: - src – The
Raster
to transform. - dst – The
Raster
in which to store the results of the transformation.
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.
Returns: The transformed Raster
.
/**
* Transforms the source {@code Raster} and stores the results in
* the destination {@code Raster}. This operation performs the
* transform band by band.
* <p>
* If the destination {@code Raster} is null, a new
* {@code Raster} is created.
* An {@code 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.
* <p>
* The coordinates of the rectangle returned by
* {@code getBounds2D(Raster)}
* are not necessarily the same as the coordinates of the
* {@code 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 {@code Raster}.
*
* @param src The {@code Raster} to transform.
* @param dst The {@code Raster} in which to store the results of the
* transformation.
*
* @return The transformed {@code 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.
*/
public final WritableRaster filter(Raster src, WritableRaster dst) {
if (src == null) {
throw new NullPointerException("src image is null");
}
if (dst == null) {
dst = createCompatibleDestRaster(src);
}
if (src == dst) {
throw new IllegalArgumentException("src image cannot be the "+
"same as the dst image");
}
if (src.getNumBands() != dst.getNumBands()) {
throw new IllegalArgumentException("Number of src bands ("+
src.getNumBands()+
") does not match number of "+
" dst bands ("+
dst.getNumBands()+")");
}
if (ImagingLib.filter(this, src, dst) == null) {
throw new ImagingOpException ("Unable to transform src image");
}
return dst;
}
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).
Params: - src – The
BufferedImage
to be transformed.
Returns: The Rectangle2D
representing the destination's bounding box.
/**
* 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).
*
* @param src The {@code BufferedImage} to be transformed.
*
* @return The {@code Rectangle2D} representing the destination's
* bounding box.
*/
public final Rectangle2D getBounds2D (BufferedImage src) {
return getBounds2D(src.getRaster());
}
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).
Params: - src – The
Raster
to be transformed.
Returns: The Rectangle2D
representing the destination's bounding box.
/**
* 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).
*
* @param src The {@code Raster} to be transformed.
*
* @return The {@code Rectangle2D} representing the destination's
* bounding box.
*/
public final Rectangle2D getBounds2D (Raster src) {
int w = src.getWidth();
int h = src.getHeight();
// Get the bounding box of the src and transform the corners
float[] pts = {0, 0, w, 0, w, h, 0, h};
xform.transform(pts, 0, pts, 0, 4);
// Get the min, max of the dst
float fmaxX = pts[0];
float fmaxY = pts[1];
float fminX = pts[0];
float fminY = pts[1];
for (int i=2; i < 8; i+=2) {
if (pts[i] > fmaxX) {
fmaxX = pts[i];
}
else if (pts[i] < fminX) {
fminX = pts[i];
}
if (pts[i+1] > fmaxY) {
fmaxY = pts[i+1];
}
else if (pts[i+1] < fminY) {
fminY = pts[i+1];
}
}
return new Rectangle2D.Float(fminX, fminY, fmaxX-fminX, fmaxY-fminY);
}
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.
Params: - src – The
BufferedImage
to be transformed. - destCM –
ColorModel
of the destination. If null, an appropriate ColorModel
is used.
Returns: The zeroed destination image.
/**
* Creates a zeroed destination image with the correct size and number of
* bands. A {@code RasterFormatException} may be thrown if the
* transformed width or height is equal to 0.
* <p>
* If {@code destCM} is null,
* an appropriate {@code ColorModel} is used; this
* {@code ColorModel} may have
* an alpha channel even if the source {@code ColorModel} is opaque.
*
* @param src The {@code BufferedImage} to be transformed.
* @param destCM {@code ColorModel} of the destination. If null,
* an appropriate {@code ColorModel} is used.
*
* @return The zeroed destination image.
*/
public BufferedImage createCompatibleDestImage (BufferedImage src,
ColorModel destCM) {
BufferedImage image;
Rectangle r = getBounds2D(src).getBounds();
// If r.x (or r.y) is < 0, then we want to only create an image
// that is in the positive range.
// If r.x (or r.y) is > 0, then we need to create an image that
// includes the translation.
int w = r.x + r.width;
int h = r.y + r.height;
if (w <= 0) {
throw new RasterFormatException("Transformed width ("+w+
") is less than or equal to 0.");
}
if (h <= 0) {
throw new RasterFormatException("Transformed height ("+h+
") is less than or equal to 0.");
}
if (destCM == null) {
ColorModel cm = src.getColorModel();
if (interpolationType != TYPE_NEAREST_NEIGHBOR &&
(cm instanceof IndexColorModel ||
cm.getTransparency() == Transparency.OPAQUE))
{
image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_ARGB);
}
else {
image = new BufferedImage(cm,
src.getRaster().createCompatibleWritableRaster(w,h),
cm.isAlphaPremultiplied(), null);
}
}
else {
image = new BufferedImage(destCM,
destCM.createCompatibleWritableRaster(w,h),
destCM.isAlphaPremultiplied(), null);
}
return image;
}
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. Params: - src – The
Raster
to be transformed.
Returns: The zeroed destination Raster
.
/**
* Creates a zeroed destination {@code Raster} with the correct size
* and number of bands. A {@code RasterFormatException} may be thrown
* if the transformed width or height is equal to 0.
*
* @param src The {@code Raster} to be transformed.
*
* @return The zeroed destination {@code Raster}.
*/
public WritableRaster createCompatibleDestRaster (Raster src) {
Rectangle2D r = getBounds2D(src);
return src.createCompatibleWritableRaster((int)r.getX(),
(int)r.getY(),
(int)r.getWidth(),
(int)r.getHeight());
}
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. Params: - 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.
/**
* Returns the location of the corresponding destination point given a
* point in the source. If {@code dstPt} is specified, it
* is used to hold the return value.
*
* @param srcPt The {@code Point2D} that represents the source
* point.
* @param dstPt The {@code Point2D} in which to store the result.
*
* @return The {@code Point2D} in the destination that corresponds to
* the specified point in the source.
*/
public final Point2D getPoint2D (Point2D srcPt, Point2D dstPt) {
return xform.transform (srcPt, dstPt);
}
Returns the affine transform used by this transform operation.
Returns: The AffineTransform
associated with this op.
/**
* Returns the affine transform used by this transform operation.
*
* @return The {@code AffineTransform} associated with this op.
*/
public final AffineTransform getTransform() {
return (AffineTransform) xform.clone();
}
Returns the rendering hints used by this transform operation.
Returns: The RenderingHints
object associated with this op.
/**
* Returns the rendering hints used by this transform operation.
*
* @return The {@code RenderingHints} object associated with this op.
*/
public final RenderingHints getRenderingHints() {
if (hints == null) {
Object val;
switch(interpolationType) {
case TYPE_NEAREST_NEIGHBOR:
val = RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR;
break;
case TYPE_BILINEAR:
val = RenderingHints.VALUE_INTERPOLATION_BILINEAR;
break;
case TYPE_BICUBIC:
val = RenderingHints.VALUE_INTERPOLATION_BICUBIC;
break;
default:
// Should never get here
throw new InternalError("Unknown interpolation type "+
interpolationType);
}
hints = new RenderingHints(RenderingHints.KEY_INTERPOLATION, val);
}
return hints;
}
// We need to be able to invert the transform if we want to
// transform the image. If the determinant of the matrix is 0,
// then we can't invert the transform.
void validateTransform(AffineTransform xform) {
if (Math.abs(xform.getDeterminant()) <= Double.MIN_VALUE) {
throw new ImagingOpException("Unable to invert transform "+xform);
}
}
}