Class ImageTranscoder
- All Implemented Interfaces:
Transcoder
- Direct Known Subclasses:
JPEGTranscoder
,PNGTranscoder
,TIFFTranscoder
Two transcoding hints (KEY_WIDTH
and
KEY_HEIGHT
) can be used to respectively specify the image
width and the image height. If only one of these keys is specified,
the transcoder preserves the aspect ratio of the original image.
The KEY_BACKGROUND_COLOR
defines the background color
to use for opaque image formats, or the background color that may
be used for image formats that support alpha channel.
The KEY_AOI
represents the area of interest to paint
in device space.
Three additional transcoding hints that act on the SVG processor can be specified:
KEY_LANGUAGE
to set the default language to use (may be
used by a <switch> SVG element for example),
KEY_USER_STYLESHEET_URI
to fix the URI of a user
stylesheet, and KEY_MM_PER_PIXEL
to specify the number of
millimeters in each pixel .
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.batik.transcoder.SVGAbstractTranscoder
SVGAbstractTranscoder.SVGAbstractTranscoderUserAgent
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final TranscodingHints.Key
The image background paint key.static final TranscodingHints.Key
The forceTransparentWhite key.Fields inherited from class org.apache.batik.transcoder.SVGAbstractTranscoder
builder, ctx, curAOI, curTxf, DEFAULT_ALLOWED_SCRIPT_TYPES, DEFAULT_DEFAULT_FONT_FAMILY, height, KEY_ALLOW_EXTERNAL_RESOURCES, KEY_ALLOWED_SCRIPT_TYPES, KEY_ALTERNATE_STYLESHEET, KEY_AOI, KEY_CONSTRAIN_SCRIPT_ORIGIN, KEY_DEFAULT_FONT_FAMILY, KEY_EXECUTE_ONLOAD, KEY_HEIGHT, KEY_LANGUAGE, KEY_MAX_HEIGHT, KEY_MAX_WIDTH, KEY_MEDIA, KEY_PIXEL_TO_MM, KEY_PIXEL_UNIT_TO_MILLIMETER, KEY_SNAPSHOT_TIME, KEY_USER_STYLESHEET_URI, KEY_WIDTH, root, userAgent, width
Fields inherited from class org.apache.batik.transcoder.XMLAbstractTranscoder
KEY_DOCUMENT_ELEMENT, KEY_DOCUMENT_ELEMENT_NAMESPACE_URI, KEY_DOM_IMPLEMENTATION, KEY_XML_PARSER_CLASSNAME, KEY_XML_PARSER_VALIDATING
Fields inherited from class org.apache.batik.transcoder.TranscoderSupport
handler, hints
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract BufferedImage
createImage
(int width, int height) Creates a new image with the specified dimension.protected ImageRenderer
Method so subclasses can modify the Renderer used to render document.protected void
Converts an image so that viewers which do not support the alpha channel will see a white background (and not a black one).protected void
transcode
(Document document, String uri, TranscoderOutput output) Transcodes the specified Document as an image in the specified output.abstract void
writeImage
(BufferedImage img, TranscoderOutput output) Writes the specified image to the specified output.Methods inherited from class org.apache.batik.transcoder.SVGAbstractTranscoder
createBridgeContext, createBridgeContext, createBridgeContext, createDocumentFactory, createUserAgent, getCanvasGraphicsNode, setImageSize, transcode
Methods inherited from class org.apache.batik.transcoder.TranscoderSupport
addTranscodingHint, getErrorHandler, getTranscodingHints, removeTranscodingHint, setErrorHandler, setTranscodingHints, setTranscodingHints
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.batik.transcoder.Transcoder
addTranscodingHint, getErrorHandler, getTranscodingHints, removeTranscodingHint, setErrorHandler, setTranscodingHints, setTranscodingHints
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Field Details
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KEY_BACKGROUND_COLOR
The image background paint key.Key: KEY_BACKGROUND_COLOR Value: Paint Default: null Required: No Description: Specify the background color to use. The color is required by opaque image formats and is used by image formats that support alpha channel. -
KEY_FORCE_TRANSPARENT_WHITE
The forceTransparentWhite key.Key: KEY_FORCE_TRANSPARENT_WHITE Value: Boolean Default: false Required: No Description: It controls whether the encoder should force the image's fully transparent pixels to be fully transparent white instead of fully transparent black. This is useful when the encoded file is displayed in a browser which does not support transparency correctly and lets the image display with a white background instead of a black background.
However, note that the modified image will display differently over a white background in a viewer that supports transparency.
Not all Transcoders use this key (in particular some formats can't preserve the alpha channel at all in which case this is not used).
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Constructor Details
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ImageTranscoder
protected ImageTranscoder()Constructs a newImageTranscoder
.
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Method Details
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transcode
protected void transcode(Document document, String uri, TranscoderOutput output) throws TranscoderException Transcodes the specified Document as an image in the specified output.- Overrides:
transcode
in classSVGAbstractTranscoder
- Parameters:
document
- the document to transcodeuri
- the uri of the document or null if anyoutput
- the ouput where to transcode- Throws:
TranscoderException
- if an error occured while transcoding
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createRenderer
Method so subclasses can modify the Renderer used to render document. -
forceTransparentWhite
Converts an image so that viewers which do not support the alpha channel will see a white background (and not a black one).- Parameters:
img
- the image to convertsppsm
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createImage
Creates a new image with the specified dimension.- Parameters:
width
- the image width in pixelsheight
- the image height in pixels
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writeImage
public abstract void writeImage(BufferedImage img, TranscoderOutput output) throws TranscoderException Writes the specified image to the specified output.- Parameters:
img
- the image to writeoutput
- the output where to store the image- Throws:
TranscoderException
- if an error occured while storing the image
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