ReplicateScaleFilter (Java SE 25 & JDK 25)
Description: declaration: module: java.desktop, package: java.awt.image, class: ReplicateScaleFilter
Keywords: java.awt.image.ReplicateScaleFilter class

# Class ReplicateScaleFilter

java.lang.Object
java.awt.image.ImageFilter
java.awt.image.ReplicateScaleFilter

All Implemented Interfaces:
  `ImageConsumer, Cloneable`

Direct Known Subclasses:
  `AreaAveragingScaleFilter`

public class ReplicateScaleFilter extends ImageFilter
An ImageFilter class for scaling images using the simplest algorithm. This class extends the basic ImageFilter Class to scale an existing image and provide a source for a new image containing the resampled image. The pixels in the source image are sampled to produce pixels for an image of the specified size by replicating rows and columns of pixels to scale up or omitting rows and columns of pixels to scale down.

It is meant to be used in conjunction with a FilteredImageSource object to produce scaled versions of existing images. Due to implementation dependencies, there may be differences in pixel values of an image filtered on different platforms.

See Also:
  - `FilteredImageSource`
  - `ImageFilter`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected int`
  `destHeight`
  The target height to scale the image.
  `protected int`
  `destWidth`
  The target width to scale the image.
  `protected Object`
  `outpixbuf`
  A `byte` array initialized with a size of `destWidth` and used to deliver a row of pixel data to the `ImageConsumer`.
  `protected int[]`
  `srccols`
  An `int` array containing information about a column of pixels.
  `protected int`
  `srcHeight`
  The height of the source image.
  `protected int[]`
  `srcrows`
  An `int` array containing information about a row of pixels.
  `protected int`
  `srcWidth`
  The width of the source image.

  ### Fields declared in class ImageFilter

  `consumer`

  ### Fields declared in interface ImageConsumer

  `COMPLETESCANLINES, IMAGEABORTED, IMAGEERROR, RANDOMPIXELORDER, SINGLEFRAME, SINGLEFRAMEDONE, SINGLEPASS, STATICIMAGEDONE, TOPDOWNLEFTRIGHT`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ReplicateScaleFilter(int width, int height)`
  Constructs a ReplicateScaleFilter that scales the pixels from its source Image as specified by the width and height parameters.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `setDimensions(int w, int h)`
  Override the dimensions of the source image and pass the dimensions of the new scaled size to the ImageConsumer.
  `void`
  `setPixels(int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize)`
  Choose which rows and columns of the delivered byte pixels are needed for the destination scaled image and pass through just those rows and columns that are needed, replicated as necessary.
  `void`
  `setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize)`
  Choose which rows and columns of the delivered int pixels are needed for the destination scaled image and pass through just those rows and columns that are needed, replicated as necessary.
  `void`
  `setProperties(Hashtable<?,?> props)`
  Passes along the properties from the source object after adding a property indicating the scale applied.

  ### Methods declared in class ImageFilter

  `clone, getFilterInstance, imageComplete, resendTopDownLeftRight, setColorModel, setHints`

  ### Methods declared in class Object

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

- ## Field Details

  - ### srcWidth

    protected int srcWidth
    The width of the source image.

  - ### srcHeight

    protected int srcHeight
    The height of the source image.

  - ### destWidth

    protected int destWidth
    The target width to scale the image.

  - ### destHeight

    protected int destHeight
    The target height to scale the image.

  - ### srcrows

    protected int[] srcrows
    An `int` array containing information about a row of pixels.

  - ### srccols

    protected int[] srccols
    An `int` array containing information about a column of pixels.

  - ### outpixbuf

    protected Object outpixbuf
    A `byte` array initialized with a size of `destWidth` and used to deliver a row of pixel data to the `ImageConsumer`.

- ## Constructor Details

  - ### ReplicateScaleFilter

    public ReplicateScaleFilter(int width, int height)
    Constructs a ReplicateScaleFilter that scales the pixels from its source Image as specified by the width and height parameters.
    Parameters:
      `width` - the target width to scale the image
      `height` - the target height to scale the image
    Throws:
      `IllegalArgumentException` - if `width` equals zero or `height` equals zero

- ## Method Details

  - ### setProperties

    public void setProperties(Hashtable<?,?> props)
    Passes along the properties from the source object after adding a property indicating the scale applied. This method invokes `super.setProperties`, which might result in additional properties being added.

    Note: This method is intended to be called by the `ImageProducer` of the `Image` whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

    Specified by:
      `setProperties` in interface `ImageConsumer`
    Overrides:
      `setProperties` in class `ImageFilter`
    Parameters:
      `props` - the properties from the source object

  - ### setDimensions

    public void setDimensions(int w, int h)
    Override the dimensions of the source image and pass the dimensions of the new scaled size to the ImageConsumer.

    Note: This method is intended to be called by the `ImageProducer` of the `Image` whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

    Specified by:
      `setDimensions` in interface `ImageConsumer`
    Overrides:
      `setDimensions` in class `ImageFilter`
    Parameters:
      `w` - the width of the source image
      `h` - the height of the source image
    See Also:
      - `ImageConsumer`

  - ### setPixels

    public void setPixels(int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize)
    Choose which rows and columns of the delivered byte pixels are needed for the destination scaled image and pass through just those rows and columns that are needed, replicated as necessary.

    Note: This method is intended to be called by the `ImageProducer` of the `Image` whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

    Specified by:
      `setPixels` in interface `ImageConsumer`
    Overrides:
      `setPixels` in class `ImageFilter`
    Parameters:
      `x` - the X coordinate of the upper-left corner of the area of pixels to be set
      `y` - the Y coordinate of the upper-left corner of the area of pixels to be set
      `w` - the width of the area of pixels
      `h` - the height of the area of pixels
      `model` - the specified `ColorModel`
      `pixels` - the array of pixels
      `off` - the offset into the `pixels` array
      `scansize` - the distance from one row of pixels to the next in the `pixels` array
    See Also:
      - `ImageConsumer.setPixels(int, int, int, int, ColorModel, byte[], int, int)`

  - ### setPixels

    public void setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize)
    Choose which rows and columns of the delivered int pixels are needed for the destination scaled image and pass through just those rows and columns that are needed, replicated as necessary.

    Note: This method is intended to be called by the `ImageProducer` of the `Image` whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

    Specified by:
      `setPixels` in interface `ImageConsumer`
    Overrides:
      `setPixels` in class `ImageFilter`
    Parameters:
      `x` - the X coordinate of the upper-left corner of the area of pixels to be set
      `y` - the Y coordinate of the upper-left corner of the area of pixels to be set
      `w` - the width of the area of pixels
      `h` - the height of the area of pixels
      `model` - the specified `ColorModel`
      `pixels` - the array of pixels
      `off` - the offset into the `pixels` array
      `scansize` - the distance from one row of pixels to the next in the `pixels` array
    See Also:
      - `ImageConsumer.setPixels(int, int, int, int, ColorModel, byte[], int, int)`