Package net.sourceforge.jiu.codecs
Class ImageLoader
java.lang.Object
net.sourceforge.jiu.codecs.ImageLoader
A convenience class with static methods to load images from files using JIU codecs.
The load methods of this class try to load an image with all codecs registered with this class.
This includes almost every codec that resides in the
net.sourceforge.jiu.codecs
package.
You can register additional codecs with registerCodecClass(net.sourceforge.jiu.codecs.ImageCodec)
or remove the usage
of codecs with removeCodecClass(net.sourceforge.jiu.codecs.ImageCodec)
.
A Codec that cannot safely identify a file to be in the format that it supports must not be used with ImageLoader.
The failure to identify typically comes from the lack of magic byte sequences defined for the format.
In order to load such a file, use the codec manually.
Example: PalmCodec
.
In order to load an image via Toolkit
(JPEG, PNG or GIF), use
ToolkitLoader
.
It combines the loading features of java.awt.Toolkit and JIU's ImageLoader.
Usage example
PixelImage image = null; try { image = ImageLoader.load("image.tif"); } catch (Exception e) { // handle exception }
- Author:
- Marco Schmidt
-
Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic ImageCodec
createCodec
(int index) Creates an instance of one of the codec classes known to ImageLoader.static FilenameFilter
Returns a filename filter (FilenameFilter
) that accepts files with name extensions typical for the image file formats known to ImageLoader.static int
Returns the number of codec classes currently known to ImageLoader.static PixelImage
Attempts to load an image from a file.static PixelImage
Attempts to load an image from a file, notifying the argument progress listeners.static PixelImage
Load an image from a file given by its name.static PixelImage
Attempts to load an image from the file with the given name, using the given list of progress listeners.static PixelImage
static void
registerCodecClass
(ImageCodec codec) Registers a codec class with ImageLoader.static void
Removes all codec classes from the internal list of codec classes.static void
removeCodecClass
(ImageCodec codec) Removes a codec class from the internal list of codec classes.private static void
-
Field Details
-
fileExtensions
-
imageCodecClasses
-
-
Constructor Details
-
ImageLoader
private ImageLoader()
-
-
Method Details
-
createCodec
Creates an instance of one of the codec classes known to ImageLoader.- Parameters:
index
- 0-based index of codec number, maximum value isgetNumCodecs()
- 1
- Returns:
- new codec object or
null
if no object could be instantiated
-
createFilenameFilter
Returns a filename filter (FilenameFilter
) that accepts files with name extensions typical for the image file formats known to ImageLoader. The filter could then be used in an file dialog likeFileDialog
.Note that this filter does not include file formats supported by the AWT
Toolkit
(GIF and JPEG, also PNG since Java 1.3).- Returns:
- filter for image file names
-
getNumCodecs
public static int getNumCodecs()Returns the number of codec classes currently known to ImageLoader. This number can be changed by registering additional codecs (registerCodecClass(net.sourceforge.jiu.codecs.ImageCodec)
) or by removing codec classes (removeCodecClass(net.sourceforge.jiu.codecs.ImageCodec)
).- Returns:
- number of known codec classes
-
load
public static PixelImage load(File file) throws IOException, InvalidFileStructureException, InvalidImageIndexException, UnsupportedTypeException Attempts to load an image from a file.- Parameters:
file
- the file from which an image is to be loaded- Returns:
- the image on success or
null
on failure - Throws:
IOException
InvalidFileStructureException
InvalidImageIndexException
UnsupportedTypeException
-
load
public static PixelImage load(File file, Vector listeners) throws IOException, InvalidFileStructureException, InvalidImageIndexException, UnsupportedTypeException Attempts to load an image from a file, notifying the argument progress listeners.- Parameters:
file
- the file to load an image fromlisteners
- a Vector of ProgressListener objects to be notified- Returns:
- an instance of a class implementing
PixelImage
- Throws:
IOException
InvalidFileStructureException
InvalidImageIndexException
UnsupportedTypeException
-
load
public static PixelImage load(String fileName) throws IOException, InvalidFileStructureException, InvalidImageIndexException, UnsupportedTypeException Load an image from a file given by its name. Simply calls load(fileName, null).- Parameters:
fileName
- name of the file from which an image is to be loaded- Returns:
- the loaded image on success, null on failure
- Throws:
IOException
InvalidFileStructureException
InvalidImageIndexException
UnsupportedTypeException
-
load
public static PixelImage load(String fileName, Vector listeners) throws IOException, InvalidFileStructureException, InvalidImageIndexException, UnsupportedTypeException Attempts to load an image from the file with the given name, using the given list of progress listeners.- Parameters:
fileName
- name of the file from which an image is to be loadedlisteners
- a list of objects implementing ProgressListener- Returns:
- the loaded image
- Throws:
IOException
InvalidFileStructureException
InvalidImageIndexException
UnsupportedTypeException
-
loadToolkitImageUri
public static PixelImage loadToolkitImageUri(String uri) throws IOException, InvalidFileStructureException, InvalidImageIndexException, UnsupportedTypeException -
registerCodecClass
Registers a codec class with ImageLoader. The argument is an instance of the class to be registered. Note that the codec class must have an empty constructor.Example: let's say you have written a new codec called ACMEImageCodec. Your codec supports loading images. Then you could register it like that:
ImageLoader.registerCodecClass(new ACMEImageCodec());
- Parameters:
codec
- an instance of the codec class to be registered
-
removeAllCodecClasses
public static void removeAllCodecClasses()Removes all codec classes from the internal list of codec classes. After a call to this method, ImageLoader will not load anything unless new codecs get registered. -
removeCodecClass
Removes a codec class from the internal list of codec classes.- Parameters:
codec
- an instance of the codec class to be removed
-
updateFileExtensions
private static void updateFileExtensions()
-