OpenJDK 27 · java.awt.Image · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
protected float	accelerationPriority Priority for accelerating this image.
private static ImageCapabilities	defaultImageCaps convenience object; we can use this single static object for all images that do not create their own image caps; it holds the default (unaccelerated) properties.
public static final int	SCALE_AREA_AVERAGING Use the Area Averaging image scaling algorithm.
public static final int	SCALE_DEFAULT Use the default image-scaling algorithm.
public static final int	SCALE_FAST Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image.
public static final int	SCALE_REPLICATE Use the image scaling algorithm embodied in the `ReplicateScaleFilter` class.
public static final int	SCALE_SMOOTH Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.
pack-priv SurfaceManager	surfaceManager
public static final Object	UndefinedProperty The `UndefinedProperty` object should be returned whenever a property which was not defined for a particular image is fetched.

Access	Constructor and Description
protected	Image() Constructor for subclasses to call.

Method Summary

Modifier and Type	Method and Description
public void	flush() Flushes all reconstructable resources being used by this Image object.
public float	Returns: value between 0 and 1, inclusive, which represents the current priority value getAccelerationPriority() Returns the current value of the acceleration priority hint.
public ImageCapabilities	Returns: an `ImageCapabilities` object that contains the capabilities of this `Image` on the specified GraphicsConfiguration. getCapabilities(GraphicsConfiguration a `GraphicsConfiguration` object. A value of null for this parameter will result in getting the image capabilities for the default `GraphicsConfiguration`. gc) Returns an ImageCapabilities object which can be inquired as to the capabilities of this Image on the specified GraphicsConfiguration.
public abstract Graphics	Returns: a graphics context to draw to the off-screen image. getGraphics() Creates a graphics context for drawing to an off-screen image.
public abstract int	Returns: the height of this image, or `-1` if the height is not yet known. getHeight(ImageObserver an object waiting for the image to be loaded. observer) Determines the height of the image.
public abstract Object	Returns: the value of the named property. getProperty(String a property name. name, ImageObserver an object waiting for this image to be loaded. observer) Gets a property of this image by name.
public Image	Returns: a scaled version of the image. getScaledInstance(int the width to which to scale the image. width, int the height to which to scale the image. height, int flags to indicate the type of algorithm to use for image resampling. hints) Creates a scaled version of this image.
public abstract ImageProducer	Returns: the image producer that produces the pixels for this image. getSource() Gets the object that produces the pixels for the image.
public abstract int	Returns: the width of this image, or `-1` if the width is not yet known. getWidth(ImageObserver an object waiting for the image to be loaded. observer) Determines the width of the image.
public void	setAccelerationPriority(float a value between 0 and 1, inclusive, where higher values indicate more importance for acceleration. A value of 0 means that this Image should never be accelerated. Other values are used simply to determine acceleration priority relative to other Images. priority) Sets a hint for this image about how important acceleration is.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

accelerationPriority back to summary

accelerationPriority	back to summary
protected float accelerationPriority Priority for accelerating this image. Subclasses are free to set different default priorities and applications are free to set the priority for specific images via the `setAccelerationPriority(float)` method. Since 1.5

protected float accelerationPriority

Priority for accelerating this image. Subclasses are free to set different default priorities and applications are free to set the priority for specific images via the setAccelerationPriority(float) method.

Since: 1.5

defaultImageCaps	back to summary
private static ImageCapabilities defaultImageCaps convenience object; we can use this single static object for all images that do not create their own image caps; it holds the default (unaccelerated) properties.

SCALE_AREA_AVERAGING back to summary

SCALE_AREA_AVERAGING	back to summary
public static final int SCALE_AREA_AVERAGING Use the Area Averaging image scaling algorithm. The image object is free to substitute a different filter that performs the same algorithm yet integrates more efficiently into the image infrastructure supplied by the toolkit. Since 1.1 See Also `java.awt.image.AreaAveragingScaleFilter`

public static final int SCALE_AREA_AVERAGING

Use the Area Averaging image scaling algorithm. The image object is free to substitute a different filter that performs the same algorithm yet integrates more efficiently into the image infrastructure supplied by the toolkit.

Since: 1.1
See Also: java.awt.image.AreaAveragingScaleFilter

SCALE_DEFAULT	back to summary
public static final int SCALE_DEFAULT Use the default image-scaling algorithm. Since 1.1

SCALE_DEFAULT

back to summary

public static final int SCALE_DEFAULT

Use the default image-scaling algorithm.

Since: 1.1

SCALE_FAST	back to summary
public static final int SCALE_FAST Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image. Since 1.1

SCALE_FAST

back to summary

public static final int SCALE_FAST

Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image.

Since: 1.1

SCALE_REPLICATE back to summary

SCALE_REPLICATE	back to summary
public static final int SCALE_REPLICATE Use the image scaling algorithm embodied in the `ReplicateScaleFilter` class. The `Image` object is free to substitute a different filter that performs the same algorithm yet integrates more efficiently into the imaging infrastructure supplied by the toolkit. Since 1.1 See Also `java.awt.image.ReplicateScaleFilter`

public static final int SCALE_REPLICATE

Use the image scaling algorithm embodied in the ReplicateScaleFilter class. The Image object is free to substitute a different filter that performs the same algorithm yet integrates more efficiently into the imaging infrastructure supplied by the toolkit.

Since: 1.1
See Also: java.awt.image.ReplicateScaleFilter

SCALE_SMOOTH	back to summary
public static final int SCALE_SMOOTH Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed. Since 1.1

SCALE_SMOOTH

back to summary

public static final int SCALE_SMOOTH

Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.

Since: 1.1

surfaceManager	back to summary
pack-priv SurfaceManager surfaceManager

UndefinedProperty	back to summary
public static final Object UndefinedProperty The `UndefinedProperty` object should be returned whenever a property which was not defined for a particular image is fetched.

Constructor Detail

Image	back to summary
protected Image() Constructor for subclasses to call.

Method Detail

flush back to summary

flush	back to summary
public void flush() Flushes all reconstructable resources being used by this Image object. This includes any pixel data that is being cached for rendering to the screen as well as any system resources that are being used to store data or pixels for the image if they can be recreated. The image is reset to a state similar to when it was first created so that if it is again rendered, the image data will have to be recreated or fetched again from its source. Examples of how this method affects specific types of Image object: BufferedImage objects leave the primary Raster which stores their pixels untouched, but flush any information cached about those pixels such as copies uploaded to the display hardware for accelerated blits. Image objects created by the Component methods which take a width and height leave their primary buffer of pixels untouched, but have all cached information released much like is done for BufferedImage objects. VolatileImage objects release all of their pixel resources including their primary copy which is typically stored on the display hardware where resources are scarce. These objects can later be restored using their `validate` method. Image objects created by the Toolkit and Component classes which are loaded from files, URLs or produced by an `ImageProducer` are unloaded and all local resources are released. These objects can later be reloaded from their original source as needed when they are rendered, just as when they were first created.

public void flush()

Flushes all reconstructable resources being used by this Image object. This includes any pixel data that is being cached for rendering to the screen as well as any system resources that are being used to store data or pixels for the image if they can be recreated. The image is reset to a state similar to when it was first created so that if it is again rendered, the image data will have to be recreated or fetched again from its source.

Examples of how this method affects specific types of Image object:

BufferedImage objects leave the primary Raster which stores their pixels untouched, but flush any information cached about those pixels such as copies uploaded to the display hardware for accelerated blits.
Image objects created by the Component methods which take a width and height leave their primary buffer of pixels untouched, but have all cached information released much like is done for BufferedImage objects.
VolatileImage objects release all of their pixel resources including their primary copy which is typically stored on the display hardware where resources are scarce. These objects can later be restored using their validate method.
Image objects created by the Toolkit and Component classes which are loaded from files, URLs or produced by an ImageProducer are unloaded and all local resources are released. These objects can later be reloaded from their original source as needed when they are rendered, just as when they were first created.

getAccelerationPriority back to summary

getAccelerationPriority	back to summary
public float getAccelerationPriority() Returns the current value of the acceleration priority hint. Returns:float value between 0 and 1, inclusive, which represents the current priority value Since 1.5 See Also `setAccelerationPriority`

public float getAccelerationPriority()

Returns the current value of the acceleration priority hint.

Returns:float: value between 0 and 1, inclusive, which represents the current priority value
Since: 1.5
See Also: setAccelerationPriority

getCapabilities back to summary

getCapabilities	back to summary
public ImageCapabilities getCapabilities(GraphicsConfiguration gc) Returns an ImageCapabilities object which can be inquired as to the capabilities of this Image on the specified GraphicsConfiguration. This allows programmers to find out more runtime information on the specific Image object that they have created. For example, the user might create a BufferedImage but the system may have no video memory left for creating an image of that size on the given GraphicsConfiguration, so although the object may be acceleratable in general, it does not have that capability on this GraphicsConfiguration. Parameters gc:GraphicsConfiguration a `GraphicsConfiguration` object. A value of null for this parameter will result in getting the image capabilities for the default `GraphicsConfiguration`. Returns:ImageCapabilities an `ImageCapabilities` object that contains the capabilities of this `Image` on the specified GraphicsConfiguration. Since 1.5 See Also `VolatileImage.getCapabilities()`

public ImageCapabilities getCapabilities(GraphicsConfiguration gc)

Returns an ImageCapabilities object which can be inquired as to the capabilities of this Image on the specified GraphicsConfiguration. This allows programmers to find out more runtime information on the specific Image object that they have created. For example, the user might create a BufferedImage but the system may have no video memory left for creating an image of that size on the given GraphicsConfiguration, so although the object may be acceleratable in general, it does not have that capability on this GraphicsConfiguration.

Parameters

gc:GraphicsConfiguration: a GraphicsConfiguration object. A value of null for this parameter will result in getting the image capabilities for the default GraphicsConfiguration.

Returns:ImageCapabilities

an ImageCapabilities object that contains the capabilities of this Image on the specified GraphicsConfiguration.

Since

1.5

See Also

VolatileImage.getCapabilities()

getGraphics back to summary

getGraphics	back to summary
public abstract Graphics getGraphics() Creates a graphics context for drawing to an off-screen image. This method can only be called for off-screen images. Returns:Graphics a graphics context to draw to the off-screen image. Exceptions UnsupportedOperationException: if called for a non-off-screen image. See Also `java.awt.Graphics`, `java.awt.Component#createImage(int, int)`

public abstract Graphics getGraphics()

Creates a graphics context for drawing to an off-screen image. This method can only be called for off-screen images.

Returns:Graphics

a graphics context to draw to the off-screen image.

Exceptions

UnsupportedOperationException:: if called for a non-off-screen image.

getHeight back to summary

getHeight	back to summary
public abstract int getHeight(ImageObserver observer) Determines the height of the image. If the height is not yet known, this method returns `-1` and the specified `ImageObserver` object is notified later. Parameters observer:ImageObserver an object waiting for the image to be loaded. Returns:int the height of this image, or `-1` if the height is not yet known. See Also `java.awt.Image#getWidth`, `java.awt.image.ImageObserver`

public abstract int getHeight(ImageObserver observer)

Determines the height of the image. If the height is not yet known, this method returns -1 and the specified ImageObserver object is notified later.

Parameters

observer:ImageObserver: an object waiting for the image to be loaded.

Returns:int

the height of this image, or -1 if the height is not yet known.

getProperty back to summary

getProperty	back to summary
public abstract Object getProperty(String name, ImageObserver observer) Gets a property of this image by name. Individual property names are defined by the various image formats. If a property is not defined for a particular image, this method returns the `UndefinedProperty` object. If the properties for this image are not yet known, this method returns `null`, and the `ImageObserver` object is notified later. The property name `"comment"` should be used to store an optional comment which can be presented to the application as a description of the image, its source, or its author. Parameters name:String a property name. observer:ImageObserver an object waiting for this image to be loaded. Returns:Object the value of the named property. Exceptions NullPointerException: if the property name is null. See Also `java.awt.image.ImageObserver`, `java.awt.Image#UndefinedProperty`

public abstract Object getProperty(String name, ImageObserver observer)

Gets a property of this image by name.

Individual property names are defined by the various image formats. If a property is not defined for a particular image, this method returns the UndefinedProperty object.

If the properties for this image are not yet known, this method returns null, and the ImageObserver object is notified later.

The property name "comment" should be used to store an optional comment which can be presented to the application as a description of the image, its source, or its author.

Parameters

name:String: a property name.
observer:ImageObserver: an object waiting for this image to be loaded.

Returns:Object

the value of the named property.

Exceptions

NullPointerException:: if the property name is null.

getScaledInstance back to summary

getScaledInstance	back to summary
public Image getScaledInstance(int width, int height, int hints) Creates a scaled version of this image. A new `Image` object is returned which will render the image at the specified `width` and `height` by default. The new `Image` object may be loaded asynchronously even if the original source image has already been loaded completely. If either `width` or `height` is a negative number then a value is substituted to maintain the aspect ratio of the original image dimensions. If both `width` and `height` are negative, then the original image dimensions are used. Parameters width:int the width to which to scale the image. height:int the height to which to scale the image. hints:int flags to indicate the type of algorithm to use for image resampling. Returns:Image a scaled version of the image. Exceptions IllegalArgumentException: if `width` or `height` is zero. Since 1.1 See Also `java.awt.Image#SCALE_DEFAULT`, `java.awt.Image#SCALE_FAST`, `java.awt.Image#SCALE_SMOOTH`, `java.awt.Image#SCALE_REPLICATE`, `java.awt.Image#SCALE_AREA_AVERAGING`

public Image getScaledInstance(int width, int height, int hints)

Creates a scaled version of this image. A new Image object is returned which will render the image at the specified width and height by default. The new Image object may be loaded asynchronously even if the original source image has already been loaded completely.

If either width or height is a negative number then a value is substituted to maintain the aspect ratio of the original image dimensions. If both width and height are negative, then the original image dimensions are used.

Parameters

width:int: the width to which to scale the image.
height:int: the height to which to scale the image.
hints:int: flags to indicate the type of algorithm to use for image resampling.

Returns:Image

a scaled version of the image.

Exceptions

IllegalArgumentException:: if width or height is zero.

Since

1.1

getSource back to summary

getSource	back to summary
public abstract ImageProducer getSource() Gets the object that produces the pixels for the image. This method is called by the image filtering classes and by methods that perform image conversion and scaling. Returns:ImageProducer the image producer that produces the pixels for this image. See Also `java.awt.image.ImageProducer`

public abstract ImageProducer getSource()

Gets the object that produces the pixels for the image. This method is called by the image filtering classes and by methods that perform image conversion and scaling.

Returns:ImageProducer: the image producer that produces the pixels for this image.
See Also: java.awt.image.ImageProducer

getWidth back to summary

getWidth	back to summary
public abstract int getWidth(ImageObserver observer) Determines the width of the image. If the width is not yet known, this method returns `-1` and the specified `ImageObserver` object is notified later. Parameters observer:ImageObserver an object waiting for the image to be loaded. Returns:int the width of this image, or `-1` if the width is not yet known. See Also `java.awt.Image#getHeight`, `java.awt.image.ImageObserver`

public abstract int getWidth(ImageObserver observer)

Determines the width of the image. If the width is not yet known, this method returns -1 and the specified ImageObserver object is notified later.

Parameters

observer:ImageObserver: an object waiting for the image to be loaded.

Returns:int

the width of this image, or -1 if the width is not yet known.

setAccelerationPriority back to summary

setAccelerationPriority	back to summary
public void setAccelerationPriority(float priority) Sets a hint for this image about how important acceleration is. This priority hint is used to compare to the priorities of other Image objects when determining how to use scarce acceleration resources such as video memory. When and if it is possible to accelerate this Image, if there are not enough resources available to provide that acceleration but enough can be freed up by de-accelerating some other image of lower priority, then that other Image may be de-accelerated in deference to this one. Images that have the same priority take up resources on a first-come, first-served basis. Parameters priority:float a value between 0 and 1, inclusive, where higher values indicate more importance for acceleration. A value of 0 means that this Image should never be accelerated. Other values are used simply to determine acceleration priority relative to other Images. Exceptions IllegalArgumentException: if `priority` is less than zero or greater than 1. Since 1.5

public void setAccelerationPriority(float priority)

Sets a hint for this image about how important acceleration is. This priority hint is used to compare to the priorities of other Image objects when determining how to use scarce acceleration resources such as video memory. When and if it is possible to accelerate this Image, if there are not enough resources available to provide that acceleration but enough can be freed up by de-accelerating some other image of lower priority, then that other Image may be de-accelerated in deference to this one. Images that have the same priority take up resources on a first-come, first-served basis.

Parameters

priority:float: a value between 0 and 1, inclusive, where higher values indicate more importance for acceleration. A value of 0 means that this Image should never be accelerated. Other values are used simply to determine acceleration priority relative to other Images.

Exceptions

IllegalArgumentException:: if priority is less than zero or greater than 1.

Since

1.5

public abstract Class Image

Field Summary

Constructor Summary

Method Summary

Field Detail

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