javax.imageio.ImageIO — clojure-interop/javax.imageio 1.0.5

A class containing static convenience methods for locating ImageReaders and ImageWriters, and performing simple encoding and decoding.

*create-image-input-stream clj

(*create-image-input-stream input)

Returns an ImageInputStream that will take its input from the given Object. The set of ImageInputStreamSpis registered with the IIORegistry class is queried and the first one that is able to take input from the supplied object is used to create the returned ImageInputStream. If no suitable ImageInputStreamSpi exists, null is returned.

The current cache settings from getUseCacheand getCacheDirectory will be used to control caching.

input - an Object to be used as an input source, such as a File, readable RandomAccessFile, or InputStream. - java.lang.Object

returns: an ImageInputStream, or null. - javax.imageio.stream.ImageInputStream

throws: java.lang.IllegalArgumentException - if input is null.

*create-image-output-stream clj

(*create-image-output-stream output)

Returns an ImageOutputStream that will send its output to the given Object. The set of ImageOutputStreamSpis registered with the IIORegistry class is queried and the first one that is able to send output from the supplied object is used to create the returned ImageOutputStream. If no suitable ImageOutputStreamSpi exists, null is returned.

The current cache settings from getUseCacheand getCacheDirectory will be used to control caching.

output - an Object to be used as an output destination, such as a File, writable RandomAccessFile, or OutputStream. - java.lang.Object

returns: an ImageOutputStream, or null. - javax.imageio.stream.ImageOutputStream

throws: java.lang.IllegalArgumentException - if output is null.

*get-cache-directory clj

(*get-cache-directory)

Returns the current value set by setCacheDirectory, or null if no explicit setting has been made.

returns: a File indicating the directory where cache files will be created, or null to indicate the system-dependent default temporary-file directory. - java.io.File

*get-image-reader clj

(*get-image-reader writer)

Returns an ImageReadercorresponding to the given ImageWriter, if there is one, or null if the plug-in for this ImageWriter does not specify a corresponding ImageReader, or if the given ImageWriter is not registered. This method is provided principally for symmetry with getImageWriter(ImageReader). Note that this method returns the "preferred" reader, which is the first in the list returned by javax.imageio.spi.ImageWriterSpi.getImageReaderSpiNames().

writer - an instance of a registered ImageWriter. - javax.imageio.ImageWriter

returns: an ImageReader, or null. - javax.imageio.ImageReader

throws: java.lang.IllegalArgumentException - if writer is null.

*get-image-readers clj

(*get-image-readers input)

Returns an Iterator containing all currently registered ImageReaders that claim to be able to decode the supplied Object, typically an ImageInputStream.

The stream position is left at its prior position upon exit from this method.

input - an ImageInputStream or other Object containing encoded image data. - java.lang.Object

returns: an Iterator containing ImageReaders. - java.util.Iterator<javax.imageio.ImageReader>

throws: java.lang.IllegalArgumentException - if input is null.

*get-image-readers-by-format-name clj

(*get-image-readers-by-format-name format-name)

Returns an Iterator containing all currently registered ImageReaders that claim to be able to decode the named format.

format-name - a String containing the informal name of a format (e.g., "jpeg" or "tiff". - java.lang.String

returns: an Iterator containing ImageReaders. - java.util.Iterator<javax.imageio.ImageReader>

throws: java.lang.IllegalArgumentException - if formatName is null.

*get-image-readers-by-mime-type clj

(*get-image-readers-by-mime-type mime-type)

Returns an Iterator containing all currently registered ImageReaders that claim to be able to decode files with the given MIME type.

mime-type - a String containing a file suffix (e.g., "image/jpeg" or "image/x-bmp"). - java.lang.String

returns: an Iterator containing ImageReaders. - java.util.Iterator<javax.imageio.ImageReader>

throws: java.lang.IllegalArgumentException - if MIMEType is null.

*get-image-readers-by-suffix clj

(*get-image-readers-by-suffix file-suffix)

Returns an Iterator containing all currently registered ImageReaders that claim to be able to decode files with the given suffix.

file-suffix - a String containing a file suffix (e.g., "jpg" or "tiff"). - java.lang.String

returns: an Iterator containing ImageReaders. - java.util.Iterator<javax.imageio.ImageReader>

throws: java.lang.IllegalArgumentException - if fileSuffix is null.

*get-image-transcoders clj

(*get-image-transcoders reader writer)

Returns an Iterator containing all currently registered ImageTranscoders that claim to be able to transcode between the metadata of the given ImageReader and ImageWriter.

reader - an ImageReader. - javax.imageio.ImageReader writer - an ImageWriter. - javax.imageio.ImageWriter

returns: an Iterator containing ImageTranscoders. - java.util.Iterator<javax.imageio.ImageTranscoder>

throws: java.lang.IllegalArgumentException - if reader or writer is null.

*get-image-writer clj

(*get-image-writer reader)

Returns an ImageWritercorresponding to the given ImageReader, if there is one, or null if the plug-in for this ImageReader does not specify a corresponding ImageWriter, or if the given ImageReader is not registered. This mechanism may be used to obtain an ImageWriter that will understand the internal structure of non-pixel metadata (as encoded by IIOMetadata objects) generated by the ImageReader. By obtaining this data from the ImageReader and passing it on to the ImageWriter obtained with this method, a client program can read an image, modify it in some way, and write it back out preserving all metadata, without having to understand anything about the structure of the metadata, or even about the image format. Note that this method returns the "preferred" writer, which is the first in the list returned by javax.imageio.spi.ImageReaderSpi.getImageWriterSpiNames().

reader - an instance of a registered ImageReader. - javax.imageio.ImageReader

returns: an ImageWriter, or null. - javax.imageio.ImageWriter

throws: java.lang.IllegalArgumentException - if reader is null.

*get-image-writers clj

(*get-image-writers type format-name)

Returns an Iterator containing all currently registered ImageWriters that claim to be able to encode images of the given layout (specified using an ImageTypeSpecifier) in the given format.

type - an ImageTypeSpecifier indicating the layout of the image to be written. - javax.imageio.ImageTypeSpecifier format-name - the informal name of the format. - java.lang.String

returns: an Iterator containing ImageWriters. - java.util.Iterator<javax.imageio.ImageWriter>

throws: java.lang.IllegalArgumentException - if any parameter is null.

*get-image-writers-by-format-name clj

(*get-image-writers-by-format-name format-name)

Returns an Iterator containing all currently registered ImageWriters that claim to be able to encode the named format.

format-name - a String containing the informal name of a format (e.g., "jpeg" or "tiff". - java.lang.String

returns: an Iterator containing ImageWriters. - java.util.Iterator<javax.imageio.ImageWriter>

throws: java.lang.IllegalArgumentException - if formatName is null.

*get-image-writers-by-mime-type clj

(*get-image-writers-by-mime-type mime-type)

Returns an Iterator containing all currently registered ImageWriters that claim to be able to encode files with the given MIME type.

mime-type - a String containing a file suffix (e.g., "image/jpeg" or "image/x-bmp"). - java.lang.String

returns: an Iterator containing ImageWriters. - java.util.Iterator<javax.imageio.ImageWriter>

throws: java.lang.IllegalArgumentException - if MIMEType is null.

*get-image-writers-by-suffix clj

(*get-image-writers-by-suffix file-suffix)

Returns an Iterator containing all currently registered ImageWriters that claim to be able to encode files with the given suffix.

file-suffix - a String containing a file suffix (e.g., "jpg" or "tiff"). - java.lang.String

returns: an Iterator containing ImageWriters. - java.util.Iterator<javax.imageio.ImageWriter>

throws: java.lang.IllegalArgumentException - if fileSuffix is null.

*get-reader-file-suffixes clj

(*get-reader-file-suffixes)

Returns an array of Strings listing all of the file suffixes associated with the formats understood by the current set of registered readers.

returns: an array of Strings. - java.lang.String[]

*get-reader-format-names clj

(*get-reader-format-names)

Returns an array of Strings listing all of the informal format names understood by the current set of registered readers.

returns: an array of Strings. - java.lang.String[]

*get-reader-mime-types clj

(*get-reader-mime-types)

Returns an array of Strings listing all of the MIME types understood by the current set of registered readers.

returns: an array of Strings. - java.lang.String[]

*get-use-cache? clj

(*get-use-cache?)

Returns the current value set by setUseCache, or true if no explicit setting has been made.

returns: true if a disk-based cache may be used for ImageInputStreams and ImageOutputStreams. - boolean

*get-writer-file-suffixes clj

(*get-writer-file-suffixes)

Returns an array of Strings listing all of the file suffixes associated with the formats understood by the current set of registered writers.

returns: an array of Strings. - java.lang.String[]

*get-writer-format-names clj

(*get-writer-format-names)

Returns an array of Strings listing all of the informal format names understood by the current set of registered writers.

returns: an array of Strings. - java.lang.String[]

*get-writer-mime-types clj

(*get-writer-mime-types)

Returns an array of Strings listing all of the MIME types understood by the current set of registered writers.

returns: an array of Strings. - java.lang.String[]

*read clj

(*read input)

Returns a BufferedImage as the result of decoding a supplied File with an ImageReader chosen automatically from among those currently registered. The File is wrapped in an ImageInputStream. If no registered ImageReader claims to be able to read the resulting stream, null is returned.

The current cache settings from getUseCacheand getCacheDirectory will be used to control caching in the ImageInputStream that is created.

Note that there is no read method that takes a filename as a String; use this method instead after creating a File from the filename.

This method does not attempt to locate ImageReaders that can read directly from a File; that may be accomplished using IIORegistry and ImageReaderSpi.

input - a File to read from. - java.io.File

returns: a BufferedImage containing the decoded contents of the input, or null. - java.awt.image.BufferedImage

throws: java.lang.IllegalArgumentException - if input is null.

*scan-for-plugins clj

(*scan-for-plugins)

Scans for plug-ins on the application class path, loads their service provider classes, and registers a service provider instance for each one found with the IIORegistry.

This method is needed because the application class path can theoretically change, or additional plug-ins may become available. Rather than re-scanning the classpath on every invocation of the API, the class path is scanned automatically only on the first invocation. Clients can call this method to prompt a re-scan. Thus this method need only be invoked by sophisticated applications which dynamically make new plug-ins available at runtime.

The getResources method of the context ClassLoader is used locate JAR files containing files named META-INF/services/javax.imageio.spi.classname, where classname is one of ImageReaderSpi, ImageWriterSpi, ImageTranscoderSpi, ImageInputStreamSpi, or ImageOutputStreamSpi, along the application class path.

The contents of the located files indicate the names of actual implementation classes which implement the aforementioned service provider interfaces; the default class loader is then used to load each of these classes and to instantiate an instance of each class, which is then placed into the registry for later retrieval.

The exact set of locations searched depends on the implementation of the Java runtime environment.

*set-cache-directory clj

(*set-cache-directory cache-directory)

Sets the directory where cache files are to be created. A value of null indicates that the system-dependent default temporary-file directory is to be used. If getUseCache returns false, this value is ignored.

cache-directory - a File specifying a directory. - java.io.File

throws: java.lang.SecurityException - if the security manager denies access to the directory.

*set-use-cache clj

(*set-use-cache use-cache)

Sets a flag indicating whether a disk-based cache file should be used when creating ImageInputStreams and ImageOutputStreams.

When reading from a standard InputStream, it may be necessary to save previously read information in a cache since the underlying stream does not allow data to be re-read. Similarly, when writing to a standard OutputStream, a cache may be used to allow a previously written value to be changed before flushing it to the final destination.

The cache may reside in main memory or on disk. Setting this flag to false disallows the use of disk for future streams, which may be advantageous when working with small images, as the overhead of creating and destroying files is removed.

On startup, the value is set to true.

use-cache - a boolean indicating whether a cache file should be used, in cases where it is optional. - boolean

*write clj

(*write im format-name output)

Writes an image using the an arbitrary ImageWriter that supports the given format to an ImageOutputStream. The image is written to the ImageOutputStream starting at the current stream pointer, overwriting existing stream data from that point forward, if present.

This method does not close the provided ImageOutputStream after the write operation has completed; it is the responsibility of the caller to close the stream, if desired.

im - a RenderedImage to be written. - java.awt.image.RenderedImage format-name - a String containing the informal name of the format. - java.lang.String output - an ImageOutputStream to be written to. - javax.imageio.stream.ImageOutputStream

returns: false if no appropriate writer is found. - boolean

throws: java.lang.IllegalArgumentException - if any parameter is null.