org.geotoolkit.image.io.plugin
Class RawImageReader

Object
  ImageReader
      SpatialImageReader
          RawImageReader

All Implemented Interfaces:

WarningProducer, Disposable, Localized

public class RawImageReader
extends SpatialImageReader

Image reader for raw binary files. The default implementation can process only inputs of type RawImageInputStream. However subclasses can process arbitrary ImageInputStream if they override the following methods:

• getWidth(int) (mandatory)
• getHeight(int) (mandatory)
• getRawDataType(int) (mandatory unless the default value, which is DataBuffer.TYPE_FLOAT, is suitable)

This class provides similar functionalities than the RAW image reader provided by the Image I/O extensions for JAI library. The main difference is that this class can be extended, and provides support for color palette and "no data value" conversion as documented in the super-class. Experience also suggests that this class is faster at least for floating point values. In addition, version 1.1 of the Image I/O extension for JAI seems to have a bug in their reading of subsampled floating point values.

Restrictions on the sample model
The current implementations requires that the image in the stream has a pixel stride equals to 1. If the pixel stride may be different, consider using the reader provided by the Image I/O extensions for JAI library instead.

Since:

3.07 (derived from 2.0)

Version:

3.07

Author:

Martin Desruisseaux (Geomatys)

See Also:

RawImageInputStream

Module:

coverage/geotk-coverageio (download)

View source code for this class

Nested Class Summary

static class

RawImageReader.Spi Service provider interface (SPI) for RawImageReaders.

Field Summary

Fields inherited from class ImageReader

availableLocales, ignoreMetadata, input, locale, minIndex, originatingProvider, progressListeners, seekForwardOnly, updateListeners, warningListeners, warningLocales

Fields inherited from interface WarningProducer

LOGGER

Constructor Summary

RawImageReader(RawImageReader.Spi provider)
Constructs a new image reader.

Method Summary

int	getHeight(int imageIndex) Returns the image's height.
int	getNumBands(int imageIndex) Returns the number of bands available for the specified image.
int	getNumImages(boolean allowSearch) Returns the number of images available from the current input source.
protected int	getRawDataType(int imageIndex) Returns the data type which most closely represents the "raw" internal data of the image.
ImageTypeSpecifier	getRawImageType(int imageIndex) Returns the data type which most closely represents the "raw" internal data of the image.
int	getWidth(int imageIndex) Returns the image's width.
boolean	isRandomAccessEasy(int imageIndex) Returns true since random access is easy in uncompressed images.
BufferedImage	read(int imageIndex, ImageReadParam param) Reads the image indexed by imageIndex.

Methods inherited from class SpatialImageReader

checkBandIndex, checkImageIndex, close, collapseNoDataValues, createMetadata, dispose, flipVertically, getDefaultReadParam, getDestination, getDimension, getGridEnvelope, getImageMetadata, getImageType, getImageTypes, getStreamMetadata, hasColors, setInput, warningOccurred

Methods inherited from class ImageReader

abort, abortRequested, addIIOReadProgressListener, addIIOReadUpdateListener, addIIOReadWarningListener, canReadRaster, checkReadParamBandSettings, clearAbortRequest, computeRegions, getAspectRatio, getAvailableLocales, getDestination, getFormatName, getImageMetadata, getInput, getLocale, getMinIndex, getNumThumbnails, getOriginatingProvider, getSourceRegion, getStreamMetadata, getThumbnailHeight, getThumbnailWidth, getTileGridXOffset, getTileGridYOffset, getTileHeight, getTileWidth, hasThumbnails, isIgnoringMetadata, isImageTiled, isSeekForwardOnly, processImageComplete, processImageProgress, processImageStarted, processImageUpdate, processPassComplete, processPassStarted, processReadAborted, processSequenceComplete, processSequenceStarted, processThumbnailComplete, processThumbnailPassComplete, processThumbnailPassStarted, processThumbnailProgress, processThumbnailStarted, processThumbnailUpdate, processWarningOccurred, processWarningOccurred, read, readAll, readAll, readAsRenderedImage, readerSupportsThumbnails, readRaster, readThumbnail, readTile, readTileRaster, removeAllIIOReadProgressListeners, removeAllIIOReadUpdateListeners, removeAllIIOReadWarningListeners, removeIIOReadProgressListener, removeIIOReadUpdateListener, removeIIOReadWarningListener, reset, setInput, setInput, setLocale

Methods inherited from class Object

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

Methods inherited from interface Localized

getLocale

Constructor Detail

RawImageReader

public RawImageReader(RawImageReader.Spi provider)

Constructs a new image reader.

Parameters:

provider - the ImageReaderSpi that is invoking this constructor, or null.

Method Detail

getNumImages

public int getNumImages(boolean allowSearch)
                 throws IllegalStateException,
                        IOException

Returns the number of images available from the current input source. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or delegates to the super-class otherwise.

Overrides:

getNumImages in class SpatialImageReader

Parameters:

allowSearch - If true, the number of images will be returned even if a search is required.

Returns:

The number of images, or -1 if allowSearch is false and a search would be required.

Throws:

IllegalStateException - if the input source has not been set.

IOException - if an error occurs reading the information from the input source.

getWidth

public int getWidth(int imageIndex)
             throws IOException

Returns the image's width. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or thrown an exception otherwise. Subclasses can override this method if they can get the image width in an other way.

Specified by:

getWidth in class ImageReader

Throws:

IOException - If the width can not be obtained of an I/O error occurred.

getHeight

public int getHeight(int imageIndex)
              throws IOException

Returns the image's height. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or thrown an exception otherwise. Subclasses can override this method if they can get the height width in an other way.

Specified by:

getHeight in class ImageReader

Throws:

IOException - If the height can not be obtained of an I/O error occurred.

getNumBands

public int getNumBands(int imageIndex)
                throws IOException

Returns the number of bands available for the specified image. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or delegates to the super-class otherwise.

Overrides:

getNumBands in class SpatialImageReader

Parameters:

imageIndex - The image index.

Returns:

The number of bands available for the specified image.

Throws:

IOException - if an error occurs reading the information from the input source.

getRawDataType

protected int getRawDataType(int imageIndex)
                      throws IOException

Returns the data type which most closely represents the "raw" internal data of the image. It should be one of DataBuffer constants. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or returns DataBuffer.TYPE_FLOAT otherwise.

Subclasses can override this method if they can get the data type in an other way. See the super-class javadoc for an explanation about how the returned type is used.

Overrides:

getRawDataType in class SpatialImageReader

Parameters:

imageIndex - The index of the image to be queried.

Returns:

The data type.

Throws:

IOException - If an error occurs reading the format information from the input source.

See Also:

SpatialImageReader.getImageType(int, ImageReadParam, SampleConverter[]), SampleConversionType.SHIFT_SIGNED_INTEGERS

getRawImageType

public ImageTypeSpecifier getRawImageType(int imageIndex)
                                   throws IOException

Returns the data type which most closely represents the "raw" internal data of the image. The default implementation fetches this information from the input stream if it is of kind RawImageInputStream, or delegates to the super-class otherwise.

Overrides:

getRawImageType in class SpatialImageReader

Parameters:

imageIndex - The index of the image to be queried.

Returns:

The image type (never null).

Throws:

IOException - If an error occurs reading the format information from the input source.

See Also:

SpatialImageReader.getImageType(int, ImageReadParam, SampleConverter[]), SpatialImageReader.getDefaultReadParam()

isRandomAccessEasy

public boolean isRandomAccessEasy(int imageIndex)
                           throws IOException

Returns true since random access is easy in uncompressed images.

Overrides:

isRandomAccessEasy in class ImageReader

Throws:

IOException

read

public BufferedImage read(int imageIndex,
                          ImageReadParam param)
                   throws IOException

Reads the image indexed by imageIndex.

Specified by:

read in class ImageReader

Parameters:

imageIndex - The index of the image to be retrieved.

param - Parameters used to control the reading process, or null.

Returns:

The desired portion of the image.

Throws:

IOException - if an input operation failed.