ColorModel (ocap 1.2 API)

java.lang.Object
- java.awt.image.ColorModel

All Implemented Interfaces:

Transparency

Direct Known Subclasses:

DirectColorModel, IndexColorModel
```
public abstract class ColorModel
extends Object
implements Transparency
```
The ColorModel abstract class encapsulates the methods for translating a pixel value to color components (for example, red, green, and blue) and an alpha component. In order to render an image to the screen, a printer, or another image, pixel values must be converted to color and alpha components. As arguments to or return values from methods of this class, pixels are represented as 32-bit ints or as arrays of primitive types. The number, order, and interpretation of color components for a ColorModel is specified by its ColorSpace. A ColorModel used with pixel data that does not include alpha information treats all pixels as opaque, which is an alpha value of 1.0.

Methods in the ColorModel class use two different representations of color and alpha components - a normalized form and an unnormalized form. In the normalized form, each component is a float value between 0.0 and 1.0. Normalized color component values are not premultiplied. All ColorModels must support the normalized form.
In the unnormalized form, each component is an unsigned integral value between 0 and 2ⁿ - 1, where n is the number of significant bits for a particular component. If pixel values for a particular ColorModel represent color samples premultiplied by the alpha sample, unnormalized color component values are also premultiplied. The unnormalized form is used only with instances of ColorModel whose ColorSpace has minimum component values of 0.0 for all components and maximum values of 1.0 for all components. The unnormalized form for color and alpha components can be a convenient representation for ColorModels whose normalized component values all lie between 0.0 and 1.0. In such cases the integral value 0 maps to 0.0 and the value 2ⁿ - 1 maps to 1.0. In other cases, such as when the normalized component values can be either negative or positive, the unnormalized form is not convenient. Such ColorModel objects throw an IllegalArgumentException when methods involving an unnormalized argument are called. Subclasses of ColorModel must specify the conditions under which this occurs.

Version:

10 Feb 1997

See Also:
IndexColorModel, DirectColorModel, Image, BufferedImage, ColorSpace, DataBuffer

Field Summary

Fields
Modifier and Type Field and Description

protected int pixel_bits
The total number of bits in the pixel.
- Fields inherited from interface java.awt.Transparency
  BITMASK, OPAQUE, TRANSLUCENT

Fields
Modifier and Type	Field and Description
`protected int`	`pixel_bits` The total number of bits in the pixel.

Constructor Summary

Constructors
Modifier	Constructor and Description
	`ColorModel(int bits)` Constructs a `ColorModel` that translates pixels of the specified number of bits to color/alpha components.
`protected`	`ColorModel(int pixel_bits, int[] bits, ColorSpace cspace, boolean hasAlpha, boolean isAlphaPremultiplied, int transparency, int transferType)` Constructs a `ColorModel` that translates pixel values to color/alpha components.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object obj)` Tests if the specified `Object` is an instance of `ColorModel` and if it equals this `ColorModel`.
`void`	`finalize()` Disposes of system resources associated with this `ColorModel` once this `ColorModel` is no longer referenced.
`abstract int`	`getAlpha(int pixel)` Returns the alpha component for the specified pixel, scaled from 0 to 255.
`abstract int`	`getBlue(int pixel)` Returns the blue color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB.
`ColorSpace`	`getColorSpace()` Returns the `ColorSpace` associated with this `ColorModel`.
`int[]`	`getComponentSize()` Returns an array of the number of bits per color/alpha component.
`int`	`getComponentSize(int componentIdx)` Returns the number of bits for the specified color/alpha component.
`abstract int`	`getGreen(int pixel)` Returns the green color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB.
`int`	`getNumColorComponents()` Returns the number of color components in this `ColorModel`.
`int`	`getNumComponents()` Returns the number of components, including alpha, in this `ColorModel`.
`int`	`getPixelSize()` Returns the number of bits per pixel described by this `ColorModel`.
`abstract int`	`getRed(int pixel)` Returns the red color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB.
`int`	`getRGB(int pixel)` Returns the color/alpha components of the pixel in the default RGB color model format.
`static ColorModel`	`getRGBdefault()` Returns a `DirectColorModel` that describes the default format for integer RGB values used in many of the methods in the AWT image interfaces for the convenience of the programmer.
`int`	`getTransferType()` Returns the transfer type of this `ColorModel`.
`int`	`getTransparency()` Returns the transparency.
`boolean`	`hasAlpha()` Returns whether or not alpha is supported in this `ColorModel`.
`int`	`hashCode()` Returns the hash code for this ColorModel.
`boolean`	`isAlphaPremultiplied()` Returns whether or not the alpha has been premultiplied in the pixel values to be translated by this `ColorModel`.
`String`	`toString()` Returns the `String` representation of the contents of this `ColorModel`object.

Methods inherited from class java.lang.Object
clone, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - pixel_bits
```
protected int pixel_bits
```
    The total number of bits in the pixel.
- Constructor Detail
  - ColorModel
```
public ColorModel(int bits)
```
    Constructs a ColorModel that translates pixels of the specified number of bits to color/alpha components. The color space is the default RGB ColorSpace, which is sRGB. Pixel values are assumed to include alpha information. If color and alpha information are represented in the pixel value as separate spatial bands, the color bands are assumed not to be premultiplied with the alpha value. The transparency type is java.awt.Transparency.TRANSLUCENT. The transfer type will be the smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT that can hold a single pixel (or DataBuffer.TYPE_UNDEFINED if bits is greater than 32). Since this constructor has no information about the number of bits per color and alpha component, any subclass calling this constructor should override any method that requires this information.
    
    Parameters:
    bits - the number of bits of a pixel
    
    Throws:
    
    IllegalArgumentException - if the number of bits in bits is less than 1
  - ColorModel
```
protected ColorModel(int pixel_bits,
          int[] bits,
          ColorSpace cspace,
          boolean hasAlpha,
          boolean isAlphaPremultiplied,
          int transparency,
          int transferType)
```
    Constructs a ColorModel that translates pixel values to color/alpha components. Color components will be in the specified ColorSpace. pixel_bits is the number of bits in the pixel values. The bits array specifies the number of significant bits per color and alpha component. Its length should be the number of components in the ColorSpace if there is no alpha information in the pixel values, or one more than this number if there is alpha information. hasAlpha indicates whether or not alpha information is present. The boolean isAlphaPremultiplied specifies how to interpret pixel values in which color and alpha information are represented as separate spatial bands. If the boolean is true, color samples are assumed to have been multiplied by the alpha sample. The transparency specifies what alpha values can be represented by this color model. The transfer type is the type of primitive array used to represent pixel values. Note that the bits array contains the number of significant bits per color/alpha component after the translation from pixel values. For example, for an IndexColorModel with pixel_bits equal to 16, the bits array might have four elements with each element set to 8.
    
    Parameters:
    pixel_bits - the number of bits in the pixel values
    bits - array that specifies the number of significant bits per color and alpha component
    cspace - the specified ColorSpace
    hasAlpha - true if alpha information is present; false otherwise
    isAlphaPremultiplied - true if color samples are assumed to be premultiplied by the alpha samples; false otherwise
    transparency - what alpha values can be represented by this color model
    transferType - the type of the array used to represent pixel values
    
    Throws:
    
    IllegalArgumentException - if the length of the bit array is less than the number of color or alpha components in this ColorModel, or if the transparency is not a valid value.
    
    IllegalArgumentException - if the sum of the number of bits in bits is less than 1 or if any of the elements in bits is less than 0.
    See Also:
    Transparency
- Method Detail
  - getRGBdefault
```
public static ColorModel getRGBdefault()
```
    Returns a DirectColorModel that describes the default format for integer RGB values used in many of the methods in the AWT image interfaces for the convenience of the programmer. The color space is the default ColorSpace, sRGB. The format for the RGB values is an integer with 8 bits each of alpha, red, green, and blue color components ordered correspondingly from the most significant byte to the least significant byte, as in: 0xAARRGGBB. Color components are not premultiplied by the alpha component. This format does not necessarily represent the native or the most efficient ColorModel for a particular device or for all images. It is merely used as a common color model format.
    
    Returns:
    a DirectColorModelobject describing default RGB values.
  - hasAlpha
```
public final boolean hasAlpha()
```
    Returns whether or not alpha is supported in this ColorModel.
    
    Returns:
    true if alpha is supported in this ColorModel; false otherwise.
  - isAlphaPremultiplied
```
public final boolean isAlphaPremultiplied()
```
    Returns whether or not the alpha has been premultiplied in the pixel values to be translated by this ColorModel. If the boolean is true, this ColorModel is to be used to interpret pixel values in which color and alpha information are represented as separate spatial bands, and color samples are assumed to have been multiplied by the alpha sample.
    
    Returns:
    true if the alpha values are premultiplied in the pixel values to be translated by this ColorModel; false otherwise.
  - getTransferType
```
public final int getTransferType()
```
    Returns the transfer type of this ColorModel. The transfer type is the type of primitive array used to represent pixel values as arrays.
    
    Returns:
    the transfer type.
  - getPixelSize
```
public int getPixelSize()
```
    Returns the number of bits per pixel described by this ColorModel.
    
    Returns:
    the number of bits per pixel.
  - getComponentSize
```
public int getComponentSize(int componentIdx)
```
    Returns the number of bits for the specified color/alpha component. Color components are indexed in the order specified by the ColorSpace. Typically, this order reflects the name of the color space type. For example, for TYPE_RGB, index 0 corresponds to red, index 1 to green, and index 2 to blue. If this ColorModel supports alpha, the alpha component corresponds to the index following the last color component.
    
    Parameters:
    componentIdx - the index of the color/alpha component
    
    Returns:
    the number of bits for the color/alpha component at the specified index.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if componentIdx is greater than the number of components or less than zero
    
    NullPointerException - if the number of bits array is null
  - getComponentSize
```
public int[] getComponentSize()
```
    Returns an array of the number of bits per color/alpha component. The array contains the color components in the order specified by the ColorSpace, followed by the alpha component, if present.
    
    Returns:
    an array of the number of bits per color/alpha component
  - getTransparency
```
public int getTransparency()
```
    Returns the transparency. Returns either OPAQUE, BITMASK, or TRANSLUCENT.
    
    Specified by:
    
    getTransparency in interface Transparency
    
    Returns:
    the transparency of this ColorModel.
    See Also:
    Transparency.OPAQUE, Transparency.BITMASK, Transparency.TRANSLUCENT
  - getNumComponents
```
public int getNumComponents()
```
    Returns the number of components, including alpha, in this ColorModel. This is equal to the number of color components, optionally plus one, if there is an alpha component.
    
    Returns:
    the number of components in this ColorModel
  - getNumColorComponents
```
public int getNumColorComponents()
```
    Returns the number of color components in this ColorModel. This is the number of components returned by ColorSpace.getNumComponents().
    
    Returns:
    the number of color components in this ColorModel.
    See Also:
    ColorSpace.getNumComponents()
  - getRed
```
public abstract int getRed(int pixel)
```
    Returns the red color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB. A color conversion is done if necessary. The pixel value is specified as an int. An IllegalArgumentException is thrown if pixel values for this ColorModel are not conveniently representable as a single int. The returned value is not a pre-multiplied value. For example, if the alpha is premultiplied, this method divides it out before returning the value. If the alpha value is 0, the red value is 0.
    
    Parameters:
    pixel - a specified pixel
    
    Returns:
    the value of the red component of the specified pixel.
  - getGreen
```
public abstract int getGreen(int pixel)
```
    Returns the green color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB. A color conversion is done if necessary. The pixel value is specified as an int. An IllegalArgumentException is thrown if pixel values for this ColorModel are not conveniently representable as a single int. The returned value is a non pre-multiplied value. For example, if the alpha is premultiplied, this method divides it out before returning the value. If the alpha value is 0, the green value is 0.
    
    Parameters:
    pixel - the specified pixel
    
    Returns:
    the value of the green component of the specified pixel.
  - getBlue
```
public abstract int getBlue(int pixel)
```
    Returns the blue color component for the specified pixel, scaled from 0 to 255 in the default RGB ColorSpace, sRGB. A color conversion is done if necessary. The pixel value is specified as an int. An IllegalArgumentException is thrown if pixel values for this ColorModel are not conveniently representable as a single int. The returned value is a non pre-multiplied value, for example, if the alpha is premultiplied, this method divides it out before returning the value. If the alpha value is 0, the blue value is 0.
    
    Parameters:
    pixel - the specified pixel
    
    Returns:
    the value of the blue component of the specified pixel.
  - getAlpha
```
public abstract int getAlpha(int pixel)
```
    Returns the alpha component for the specified pixel, scaled from 0 to 255. The pixel value is specified as an int. An IllegalArgumentException is thrown if pixel values for this ColorModel are not conveniently representable as a single int.
    
    Parameters:
    pixel - the specified pixel
    
    Returns:
    the value of alpha component of the specified pixel.
  - getRGB
```
public int getRGB(int pixel)
```
    Returns the color/alpha components of the pixel in the default RGB color model format. A color conversion is done if necessary. The pixel value is specified as an int. An IllegalArgumentException thrown if pixel values for this ColorModel are not conveniently representable as a single int. The returned value is in a non pre-multiplied format. For example, if the alpha is premultiplied, this method divides it out of the color components. If the alpha value is 0, the color values are 0.
    
    Parameters:
    pixel - the specified pixel
    
    Returns:
    the RGB value of the color/alpha components of the specified pixel.
    See Also:
    getRGBdefault()
  - equals
```
public boolean equals(Object obj)
```
    Tests if the specified Object is an instance of ColorModel and if it equals this ColorModel.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    obj - the Object to test for equality
    
    Returns:
    true if the specified Object is an instance of ColorModel and equals this ColorModel; false otherwise.
    See Also:
    Object.hashCode(), Hashtable
  - hashCode
```
public int hashCode()
```
    Returns the hash code for this ColorModel.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    a hash code for this ColorModel.
    See Also:
    Object.equals(java.lang.Object), Hashtable
  - getColorSpace
```
public final ColorSpace getColorSpace()
```
    Returns the ColorSpace associated with this ColorModel.
    
    Returns:
    the ColorSpace of this ColorModel.
  - finalize
```
public void finalize()
```
    Disposes of system resources associated with this ColorModel once this ColorModel is no longer referenced.
    
    Overrides:
    
    finalize in class Object
  - toString
```
public String toString()
```
    Returns the String representation of the contents of this ColorModelobject.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a String representing the contents of this ColorModel object.

Class ColorModel

Field Summary

Fields inherited from interface java.awt.Transparency

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

pixel_bits

Constructor Detail

ColorModel

ColorModel

Method Detail

getRGBdefault

hasAlpha

isAlphaPremultiplied

getTransferType

getPixelSize

getComponentSize

getComponentSize

getTransparency

getNumComponents

getNumColorComponents

getRed

getGreen

getBlue

getAlpha

getRGB

equals

hashCode

getColorSpace

finalize

toString