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ImageWriter
ClassImageReader
s for a particular format using a method
from the ImageIO
class, we can obtain a list of
ImageWriter
s:
Iterator writers = ImageIO.getImageWritersByFormatName("png"); ImageWriter writer = (ImageWriter)writers.next();Once an
ImageWriter
has
been obtained, its destination must be set to an
ImageOutputStream
:
File f = new File("c:\images\myimage.png"); ImageOutputStream ios = ImageIO.createImageOutputStream(f); writer.setOutput(ios);Finally, the image may be written to the output stream:
BufferedImage bi; writer.write(bi);
IIOImage
class is
use to store references to an image, one or more thumbnail images,
and metadata (non-image data) associated with the image. Metadata
will be discussed below; for now, we will simply pass
null
as the value for the metadata-related parameters.
The ImageWriter
class
contains a write
method that creates a new file from
an IIOImage
, and a writeInsert
method
that adds an IIOImage
to an existing file . By calling
the two in sequence a multi-image file may be written:
BufferedImage first_bi, second_bi; IIOImage first_IIOImage = new IIOImage(first_bi, null, null); IIOImage second_IIOImage = new IIOImage(second_bi, null, null); writer.write(null, first_IIOImage, null); if (writer.canInsertImage(1)) { writer.writeInsert(1, second_IIOImage, null); } else { System.err.println("Writer can't append a second image!"); }