|
|||||||||
| Home >> All >> javax >> [ imageio overview ] | PREV CLASS NEXT CLASS | ||||||||
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||
javax.imageio
Class IIOParam
java.lang.Objectjavax.imageio.IIOParam
- Direct Known Subclasses:
- ImageReadParam, ImageWriteParam
- public abstract class IIOParam
- extends java.lang.Object
An IIOParam stores parameters used when encoding or decoding image streams. ImageReadParam and ImageWriteParam extend this abstract base class. IIOParams allow control over how source pixels converted into destination pixels. This conversion can take place between a stream and in-memory image data, when an image reader is doing the conversion, or a writer can be doing the conversion from an in-memory source to a stream destination. An image reader can be restricted to only read from a given region; likewise a writer can be restricted to only write output to a given region. For image readers and writers, IIOParam supports image pixelation -- where the input image is approximated by the output image using larger-sized pixel blocks. For example: FIXME IIOParams can control how pixels are combined into larger blocks using sub-sampling matrices. For example: FIXME They can also control which source bands are read and written; this example reads the RGBA (red, green, blue, transparency) data from a PNG image and outputs just the red and transparency bands: FIXME
| Field Summary | |
protected IIOParamController |
controller
The controller called by this IIOParam to retrieve parameters. |
protected IIOParamController |
defaultController
The default controller called by this IIOParam to retrieve parameters. |
protected java.awt.Point |
destinationOffset
The offset in the destination where the upper-left decoded/encoded pixel should be located. |
protected ImageTypeSpecifier |
destinationType
Sets the output colour type when writing or the destination image type when reading. |
private boolean |
no_controller
Indicates whether or not the controller has been explicitly set to null. |
protected int[] |
sourceBands
An array indicating which source bands will be used or null. |
protected java.awt.Rectangle |
sourceRegion
The source pixel region or null. |
protected int |
sourceXSubsampling
Sample every sourceXSubsampling'th pixel in the source image when pixelating the destination image in the horizontal direction. |
protected int |
sourceYSubsampling
Sample every sourceYSubsampling'th pixel in the source image when pixelating the destination image in the vertical direction. |
protected int |
subsamplingXOffset
Start sampling at this horizontal offset within the source region when pixelating the destination image in the horizontal direction. |
protected int |
subsamplingYOffset
Start sampling at this vertical offset within the source region when pixelating the destination image in the vertical direction. |
| Constructor Summary | |
protected |
IIOParam()
Constructs an IIOParam object. |
| Method Summary | |
boolean |
activateController()
Activates the parameter controller by calling its activate method and passing it this IIOParam. |
IIOParamController |
getController()
Retrieve the currently set controller if one has been set, or the default controller, or null if the controller has been explicitly set to null. |
IIOParamController |
getDefaultController()
Retrieve the default controller regardless of whether or not a non-default controller has been set. |
java.awt.Point |
getDestinationOffset()
Retrieve the offset in the destination where the upper-left decoded/encoded pixel should be located. |
ImageTypeSpecifier |
getDestinationType()
Retrieve the currently set image-type specifier or null if none has been set. |
int[] |
getSourceBands()
Retrieve the current source band values or null if source band values have not been set. |
java.awt.Rectangle |
getSourceRegion()
Retrieve the source rectangle from which pixels should be read or null if no source region has been set. |
int |
getSourceXSubsampling()
Retrieve the number of pixel columns to advance before taking a pixel sample. |
int |
getSourceYSubsampling()
Retrieve the number of pixel rows to advance before taking a pixel sample. |
int |
getSubsamplingXOffset()
Retrieve the number of pixel columns to advance before taking any pixel samples. |
int |
getSubsamplingYOffset()
Retrieve the number of pixel rows to advance before taking any pixel samples. |
boolean |
hasController()
Check if a non-null controller is currently available. |
void |
setController(IIOParamController controller)
Sets the controller for this IIOParam. |
void |
setDestinationOffset(java.awt.Point destinationOffset)
Specify the destination pixel offset. |
void |
setDestinationType(ImageTypeSpecifier destinationType)
Set the destination image type. |
void |
setSourceBands(int[] sourceBands)
Set the indices of the source bands to be used. |
void |
setSourceRegion(java.awt.Rectangle sourceRegion)
Set the source region from which to read. |
void |
setSourceSubsampling(int sourceXSubsampling,
int sourceYSubsampling,
int subsamplingXOffset,
int subsamplingYOffset)
Set the source sampling intervals and offsets. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
controller
protected IIOParamController controller
- The controller called by this IIOParam to retrieve parameters.
defaultController
protected IIOParamController defaultController
- The default controller called by this IIOParam to retrieve
parameters.
destinationOffset
protected java.awt.Point destinationOffset
- The offset in the destination where the upper-left
decoded/encoded pixel should be located.
destinationType
protected ImageTypeSpecifier destinationType
- Sets the output colour type when writing or the destination image
type when reading.
sourceBands
protected int[] sourceBands
- An array indicating which source bands will be used or null.
sourceRegion
protected java.awt.Rectangle sourceRegion
- The source pixel region or null.
sourceXSubsampling
protected int sourceXSubsampling
- Sample every sourceXSubsampling'th pixel in the source image when
pixelating the destination image in the horizontal direction.
sourceYSubsampling
protected int sourceYSubsampling
- Sample every sourceYSubsampling'th pixel in the source image when
pixelating the destination image in the vertical direction.
subsamplingXOffset
protected int subsamplingXOffset
- Start sampling at this horizontal offset within the source region
when pixelating the destination image in the horizontal
direction.
subsamplingYOffset
protected int subsamplingYOffset
- Start sampling at this vertical offset within the source region
when pixelating the destination image in the vertical direction.
no_controller
private boolean no_controller
- Indicates whether or not the controller has been explicitly set
to null.
| Constructor Detail |
IIOParam
protected IIOParam()
- Constructs an IIOParam object.
| Method Detail |
activateController
public boolean activateController()
- Activates the parameter controller by calling its activate method
and passing it this IIOParam. A true return value indicates that
this IIOParam's values are ready for the next read or write
operation. A return value of false means that this IIOParam's
values have not been affected because the controller operations
were cancelled.
getController
public IIOParamController getController()
- Retrieve the currently set controller if one has been set, or the
default controller, or null if the controller has been explicitly
set to null.
getDefaultController
public IIOParamController getDefaultController()
- Retrieve the default controller regardless of whether or not a
non-default controller has been set. The default controller may
be null.
getDestinationOffset
public java.awt.Point getDestinationOffset()
- Retrieve the offset in the destination where the upper-left
decoded/encoded pixel should be located. (0, 0) by default.
getDestinationType
public ImageTypeSpecifier getDestinationType()
- Retrieve the currently set image-type specifier or null if none
has been set.
getSourceBands
public int[] getSourceBands()
- Retrieve the current source band values or null if source band
values have not been set.
The returned array is a copy of this IIOParam's source band
array.
getSourceRegion
public java.awt.Rectangle getSourceRegion()
- Retrieve the source rectangle from which pixels should be read or
null if no source region has been set.
getSourceXSubsampling
public int getSourceXSubsampling()
- Retrieve the number of pixel columns to advance before taking a
pixel sample.
getSourceYSubsampling
public int getSourceYSubsampling()
- Retrieve the number of pixel rows to advance before taking a
pixel sample.
getSubsamplingXOffset
public int getSubsamplingXOffset()
- Retrieve the number of pixel columns to advance before taking any
pixel samples.
getSubsamplingYOffset
public int getSubsamplingYOffset()
- Retrieve the number of pixel rows to advance before taking any
pixel samples.
hasController
public boolean hasController()
- Check if a non-null controller is currently available.
setController
public void setController(IIOParamController controller)
- Sets the controller for this IIOParam. This is the controller
that will be activated when activateController is called. The
argument controller overrides this IIOParam's default controller.
If the argument is null then no controller will be set, not even
the default one. To reset the default controller call
setController(getDefaultController()).
setDestinationType
public void setDestinationType(ImageTypeSpecifier destinationType)
- Set the destination image type.
If this value is set on an image reader then its read method will
return a new BufferedImage of the specified destination type. In
this case any destination image set using setDestination() is
ignored.
If this is set on an image writer then the destination type
affects only the colour model of the destination image. The
destination type's SampleModel is ignored. The destination
type's ColorModel will override the source image's colour model.
setDestinationOffset
public void setDestinationOffset(java.awt.Point destinationOffset)
- Specify the destination pixel offset. Image writers are only
affected by this setting when ImageWriter.replacePixels is called
in which case the offset is into the region of pixels being
changed.
setSourceBands
public void setSourceBands(int[] sourceBands)
- Set the indices of the source bands to be used. Duplicate
indices are not allowed. A value of null means use all source
bands. The argument array is copied and stored, so subsequent
updates to it will not be reflected in this IIOParam.
setSourceRegion
public void setSourceRegion(java.awt.Rectangle sourceRegion)
- Set the source region from which to read. The number of pixels
sampled from the source region depends on the source sub-sampling
settings. If the combination of this sourceRegion and the
current sub-sampling settings would result in no pixels being
sampled then an IllegalStateException will be thrown.
The source region is specified in the source image coordinate
system which has point (0, 0) at the top-left and increases down
and to the right. The argument source region is clipped to the
image boundaries at read-time.
A null argument sets the source region to null meaning that the
whole image should be read.
setSourceSubsampling
public void setSourceSubsampling(int sourceXSubsampling,
int sourceYSubsampling,
int subsamplingXOffset,
int subsamplingYOffset)
- Set the source sampling intervals and offsets. Every
sourceXSubsampling'th pixel horizontally and
sourceYSubsampling'th pixel vertically will be sampled. Sampling
will being a the subsamplingXOffset'th column and the
subsamplingYOffset'th row.
Horizontally, the number of sampled pixels will be:
floor((width - subsamplingXOffset + sourceXSubsampling - 1) / sourceXSubsampling)
Vertically:
floor((height - subsamplingYOffset + sourceYSubsampling - 1) / sourceYSubsampling)
If the current source region setting is such that the given
sub-sampling arguments would produce zero pixel samples, an
IllegalStateException is thrown.
The offset parameters can be used to make source regions overlap
when tiling across an image. This can eliminate seams and
better-tile images whose width or height is not a multiple of the
sampling interval.
|
|||||||||
| Home >> All >> javax >> [ imageio overview ] | PREV CLASS NEXT CLASS | ||||||||
|
SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||