org.geotools.gce.grassraster.core

Class GrassBinaryRasterReadHandler

Object

GrassBinaryRasterReadHandler

All Implemented Interfaces:

Closeable, AutoCloseable

public class GrassBinaryRasterReadHandler
extends Object
implements Closeable

Grass binary data input/ouput handler.

Reading and writing is supported.

Since:

3.0

Author:

Andrea Antonello (www.hydrologis.com)

See Also:

GrassBinaryImageReader, GrassBinaryImageReadParam, GrassBinaryImageMetadata

Constructor Summary

Constructors

Constructor and Description
GrassBinaryRasterReadHandler(File cellFile) the constructor to build a GrassBinaryRasterReadHandler usable for reading grass rasters.

Method Summary

Modifier and Type	Method and Description
void	abort() sets the abortrequired flag to true.
void	close() closes the I/O streams.
List<String>	getCategories() Getter for the categories.
List<String>	getColorRules(double[] range) Getter for the colorrules.
CoordinateReferenceSystem	getCrs() Reads the crs definition for the map.
JGrassRegion	getNativeRasterRegion() Getter for nativeRasterRegion.
double	getNoData() Getter for the noData value.
double[]	getRange()
int	getRasterMapHeight()
int	getRasterMapWidth()
SampleModel	getSampleModel() returns the SampleModel compatible with the WritableRaster.
boolean	isAborting() Getter for the abortrequired flag.
void	parseHeaderAndAccessoryFiles() Determines the metadata of the raster map.
WritableRaster	readRaster(ImageReadParam param) reads a grass raster, given the read parameters.
WritableRaster	readRaster(ImageReadParam param, boolean useSubSamplingAsRequestedRowcols, boolean castDoubleToFloating, ProgressListener monitor) Reads a grass raster, adding the possibility to override subsampling.
void	setNoData(double noData) Setter for the noData value.

Methods inherited from class Object

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

Constructor Detail

GrassBinaryRasterReadHandler

public GrassBinaryRasterReadHandler(File cellFile)

the constructor to build a GrassBinaryRasterReadHandler usable for reading grass rasters.

Parameters:

cellFile - the file of the raw raster data.

Method Detail

readRaster

public WritableRaster readRaster(ImageReadParam param,
                                 boolean useSubSamplingAsRequestedRowcols,
                                 boolean castDoubleToFloating,
                                 ProgressListener monitor)
                          throws IOException,
                                 DataFormatException

Reads a grass raster, adding the possibility to override subsampling.

Parameters:

param - the read parameters.

useSubSamplingAsRequestedRowcols - a flag that gives the possibility to bypass the imageio subsampling mechanism. With GRASS maps this is often more performing in some boundary situations. In the case this flag is set to true, the subsampling values will be handled as the requested columns and rows.

castDoubleToFloating - a flag that gives the possibility to force the reading of a map as a floating point map. This is necessary right now because of a imageio bug: https://jai-imageio-core.dev.java.net /issues/show_bug.cgi?id=180

Returns:

the read raster

Throws:

IOException

DataFormatException

readRaster

public WritableRaster readRaster(ImageReadParam param)
                          throws IOException,
                                 DataFormatException

reads a grass raster, given the read parameters.

The data are read into a single banded, floating point WritableRaster. A RectIter can be used to access the data afterwards.

Parameters:

param - the read parameters.

Returns:

the read raster

Throws:

IOException

DataFormatException

parseHeaderAndAccessoryFiles

public void parseHeaderAndAccessoryFiles()
                                  throws IOException

Determines the metadata of the raster map.

Reads the map type given a file and its mapset, the information from the header file in the cellhd directory and determines the geographic limits, format of the data, etc from the file. NOTE: for further informations about cell header files, read the package description.

INFO: this is a reader method.

Throws:

IOException

getNativeRasterRegion

public JGrassRegion getNativeRasterRegion()

Getter for nativeRasterRegion.

INFO: this is a reader method.

Returns:

the nativeRasterRegion.

getColorRules

public List<String> getColorRules(double[] range)
                           throws IOException

Getter for the colorrules.

INFO: this is a reader method.

Returns:

the list of single colorrules.

Throws:

IOException

getCategories

public List<String> getCategories()
                           throws IOException

Getter for the categories.

INFO: this is a reader method.

Returns:

the attribute table as read in the categories file

Throws:

IOException

close

public void close()
           throws IOException

closes the I/O streams.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

abort

public void abort()

sets the abortrequired flag to true.

As soon as possible that should abort the reader.

isAborting

public boolean isAborting()

Getter for the abortrequired flag.

Returns:

the abortRequired flag.

setNoData

public void setNoData(double noData)

Setter for the noData value.

Parameters:

noData - the nodata value to set.

getNoData

public double getNoData()

Getter for the noData value.

Returns:

the nodata value.

getCrs

public CoordinateReferenceSystem getCrs()
                                 throws IOException

Reads the crs definition for the map.

The definition for grass maps is held in the location. Grass projection definitions are usually in a non parsable internal format. In JGrass we ask the user to choose the CRS. If the user doesn't do so, the CRS will result to be undefined.

Returns:

the CoordinateReferenceSystem for the map. Null if it is not defined.

Throws:

IOException - if there were problems in parsing the CRS file.

getSampleModel

public SampleModel getSampleModel()

returns the SampleModel compatible with the WritableRaster.

Returns:

the sample model compatible with the created raster

getRasterMapWidth

public int getRasterMapWidth()

getRasterMapHeight

public int getRasterMapHeight()

getRange

public double[] getRange()