Class ImageHDU

java.lang.Object

nom.tam.fits.BasicHDU<ImageData>

nom.tam.fits.ImageHDU

All Implemented Interfaces:

FitsElement

Direct Known Subclasses:

NullDataHDU

public class ImageHDU
extends BasicHDU<ImageData>

Header/data unit for images. Image HDUs are suitable for storing monolithic regular numerical arrays in 1 to 255 dimensions, such as a double[], float[][], or short[][][]. ((FITS supports up to 999 dimensions, but Java support maxes at at 255 -- however it's unlikely you'll find this to be a serious limitation.)

See Also:

• ImageData

Field Summary

Fields inherited from class BasicHDU

BITPIX_BYTE, BITPIX_DOUBLE, BITPIX_FLOAT, BITPIX_INT, BITPIX_LONG, BITPIX_SHORT

Modifier and Type	Field	Description
static final int	BITPIX_BYTE	Deprecated. Use Bitpix.VALUE_FOR_BYTE instead.
static final int	BITPIX_DOUBLE	Deprecated. Use Bitpix.VALUE_FOR_DOUBLE instead.
static final int	BITPIX_FLOAT	Deprecated. Use Bitpix.VALUE_FOR_FLOAT instead.
static final int	BITPIX_INT	Deprecated. Use Bitpix.VALUE_FOR_INT instead.
static final int	BITPIX_LONG	Deprecated. Use Bitpix.VALUE_FOR_LONG instead.
static final int	BITPIX_SHORT	Deprecated. Use Bitpix.VALUE_FOR_SHORT instead.

Constructor Summary

Constructors

Constructor	Description
ImageHDU(Header h, ImageData d)	Deprecated. (for internal use) Its visibility should be reduced to package level in the future.

Method Summary

Modifier and Type	Method	Description
static ImageData	encapsulate(Object o)	Deprecated. (for internal use) Use ImageData.from(Object) instead.
long	getBlankValue()	Returns the integer value that signifies blank (missing or null) data in an integer image.
double	getBScale()	Returns the floating-point increment between adjacent integer values in the image.
String	getBUnit()	Returns the name of the physical unit in which images are represented.
double	getBZero()	Returns the floating-point value that corresponds to an 0 integer value in the image.
StandardImageTiler	getTiler()	Returns the class that can be used to divide this image into tiles that may be processed separately (and in parallel).
void	info(PrintStream stream)	Print out some information about this HDU.
static boolean	isData(Object o)	Deprecated. (for internal use) Will reduce visibility in the future
static boolean	isHeader(Header hdr)	Deprecated. (for internal use) Will reduce visibility in the future
static ImageData	manufactureData(Header hdr)	Deprecated. (for internal use) Will reduce visibility in the future
static Header	manufactureHeader(Data d)	Deprecated. (for internal use) Will reduce visibility in the future

Methods inherited from class BasicHDU

addValue, addValue, addValue, addValue, addValue, addValue, addValue, addValue, calcChecksum, card, getAuthor, getAxes, getBitpix, getBitPix, getCreationDate, getData, getDummyHDU, getEpoch, getEquinox, getFileOffset, getGroupCount, getHeader, getInstrument, getKernel, getMaximumValue, getMinimumValue, getObject, getObservationDate, getObserver, getOrigin, getParameterCount, getReference, getSize, getStoredChecksum, getStoredDatasum, getTelescope, getTrimmedString, getTrimmedString, read, reset, rewrite, rewriteable, setChecksum, verifyDataIntegrity, verifyIntegrity, write

Modifier and Type	Method	Description
void	addValue(String key, boolean val, String comment)	Add information to the header.
void	addValue(String key, double val, String comment)	Add information to the header.
void	addValue(String key, int val, String comment)	Add information to the header.
void	addValue(String key, String val, String comment)	Add information to the header.
void	addValue(IFitsHeader key, boolean val)	Add information to the header.
void	addValue(IFitsHeader key, double val)	Add information to the header.
void	addValue(IFitsHeader key, int val)	Add information to the header.
void	addValue(IFitsHeader key, String val)	Add information to the header.
long	calcChecksum()	Deprecated. Use BasicHDU.verifyIntegrity() instead when appropriate.
HeaderCardBuilder	card(IFitsHeader key)	Returns a header card builder for filling the header cards using the builder pattern.
String	getAuthor()	Return the name of the person who compiled the information in the data associated with this header.
int[]	getAxes()	In FITS files the index represented by NAXIS1 is the index that changes most rapidly.
Bitpix	getBitpix()	Return the Bitpix enum type for this HDU.
final int	getBitPix()	Deprecated. (for internal use) Will reduce visibility or remove entirely in the future.
Date	getCreationDate()	Get the FITS file creation date as a Date object.
ImageData	getData()	Returns the data component of this HDU.
static NullDataHDU	getDummyHDU()	Deprecated. Use NullDataHDU instead.
double	getEpoch()	Deprecated. use BasicHDU.getEquinox() instead
double	getEquinox()	Get the equinox in years for the celestial coordinate system in which positions given in either the header or data are expressed.
long	getFileOffset()	Returns the byte offset at which this element starts ina file.
int	getGroupCount()	Deprecated. Should not be exposed outside of RandomGroupsHDU -- will reduce visibility in the future/
Header	getHeader()	Returns the FITS header component of this HDU
String	getInstrument()	Get the name of the instrument which was used to acquire the data in this FITS file.
final Object	getKernel()	Returns the underlying Java object (usually an array of some type) that stores the data internally.
double	getMaximumValue()	Return the minimum valid value in the array.
double	getMinimumValue()	Return the minimum valid value in the array.
String	getObject()	Get the name of the observed object in this FITS file.
Date	getObservationDate()	Get the FITS file observation date as a Date object.
String	getObserver()	Get the name of the person who acquired the data in this FITS file.
String	getOrigin()	Get the name of the organization which created this FITS file.
int	getParameterCount()	Deprecated. Should not be exposed outside of RandomGroupsHDU -- will reduce visibility in the future.
String	getReference()	Return the citation of a reference where the data associated with this header are published.
long	getSize()	Returns the size of this elements in the FITS representation.
long	getStoredChecksum()	Deprecated. Not very useful, since it has no meaning other than ensuring that the checksum of the HDU yields (int) -1 (that is 0xffffffff) after including this value for the CHECKSUM keyword in the header.
long	getStoredDatasum()	Returns the FITS checksum for the HDU's data that is stored in the header of this HDU under the DATASUM keyword.
String	getTelescope()	Get the name of the telescope which was used to acquire the data in this FITS file.
String	getTrimmedString(String keyword)	Deprecated. (for internal use) Will reduced visibility in the future.
String	getTrimmedString(IFitsHeader keyword)	Deprecated. (for internal use) Will reduced visibility in the future.
void	read(ArrayDataInput stream)	Read a FITS element from the input, starting at the current position.
boolean	reset()	Reset the input stream to point to the beginning of this element
void	rewrite()	Rewrite the contents of the element in place.
boolean	rewriteable()	Checks if we can write this element back to its source.
void	setChecksum()	Computes the checksums for this HDU and stores the CHECKSUM and DATASUM values in the header.
boolean	verifyDataIntegrity()	Checks that the HDUs data checksum is correct.
boolean	verifyIntegrity()	Checks the HDU's integrity, using the recorded CHECKSUM and/or DATASUM keywords if present.
void	write(ArrayDataOutput stream)	Writes the contents of the element to a data sink, adding padding as necessary if the element (such as a header or data segment) is expected to complete the FITS block of 2880 bytes.

Methods inherited from class Object

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

Constructor Details

ImageHDU

@Deprecated
public ImageHDU(Header h,
 ImageData d)

Deprecated.

(for internal use) Its visibility should be reduced to package level in the future.

Build an image HDU using the supplied data.

Parameters:

h - the header for the image.

d - the data used in the image.

Method Details

encapsulate

@Deprecated
public static ImageData encapsulate(Object o)
                             throws IllegalArgumentException,
FitsException

Deprecated.

(for internal use) Use ImageData.from(Object) instead. Will reduce visibility in the future

Parameters:

o - object to encapsulate

Returns:

Encapsulate an object as an ImageHDU.

Throws:

FitsException - does not actually throw this exception

IllegalArgumentException - if the data is not a regular primitive numerical array suitable for an image.

isData

@Deprecated
public static boolean isData(Object o)

Deprecated.

(for internal use) Will reduce visibility in the future

Parameters:

o - The Object being tested.

Returns:

is this object can be described as a FITS image.

isHeader

@Deprecated
public static boolean isHeader(Header hdr)

Deprecated.

(for internal use) Will reduce visibility in the future

Check that this HDU has a valid header for this type.

Parameters:

hdr - header to check

Returns:

true if this HDU has a valid header.

manufactureData

@Deprecated
public static ImageData manufactureData(Header hdr)
                                 throws FitsException

Deprecated.

(for internal use) Will reduce visibility in the future

Prepares a data object into which the actual data can be read from an input subsequently or at a later time.

Parameters:

hdr - The FITS header that describes the data

Returns:

A data object that support reading content from a stream.

Throws:

FitsException - if the data could not be prepared to prescriotion.

manufactureHeader

@Deprecated
public static Header manufactureHeader(Data d)
                                throws FitsException

Deprecated.

(for internal use) Will reduce visibility in the future

Prepares a data object into which the actual data can be read from an input subsequently or at a later time.

Parameters:

d - The FITS data content of this HDU

Returns:

A data object that support reading content from a stream.

Throws:

FitsException - if the data could not be prepared to prescriotion.

getTiler

public StandardImageTiler getTiler()

Returns the class that can be used to divide this image into tiles that may be processed separately (and in parallel).

Returns:

image tiler for this image instance.

See Also:

• ImageData.getTiler()

info

public void info(PrintStream stream)

Description copied from class: BasicHDU

Print out some information about this HDU.

Specified by:

info in class BasicHDU<ImageData>

Parameters:

stream - the printstream to write the info on

getBUnit

public String getBUnit()

Returns the name of the physical unit in which images are represented.

Overrides:

getBUnit in class BasicHDU<ImageData>

Returns:

the standard name of the physical unit in which the image is expressed, e.g. "Jy beam^{-1}".

getBlankValue

public long getBlankValue()
                   throws FitsException

Returns the integer value that signifies blank (missing or null) data in an integer image.

Overrides:

getBlankValue in class BasicHDU<ImageData>

Returns:

the integer value used for identifying blank / missing data in integer images.

Throws:

FitsException - if the header does not specify a blanking value or if it is not appropriate for the type of imge (that is not an integer type image)

getBScale

public double getBScale()

Returns the floating-point increment between adjacent integer values in the image. Strictly speaking, only integer-type images should define a quantization scaling, but there is no harm in having this value in floating-point images also -- which may be interpreted as a hint for quantization, perhaps.

Overrides:

getBScale in class BasicHDU<ImageData>

Returns:

the floating-point quantum that corresponds to the increment of 1 in the integer data representation.

See Also:

• getBZero()

getBZero

public double getBZero()

Returns the floating-point value that corresponds to an 0 integer value in the image. Strictly speaking, only integer-type images should define a quantization offset, but there is no harm in having this value in floating-point images also -- which may be interpreted as a hint for quantization, perhaps.

Overrides:

getBZero in class BasicHDU<ImageData>

Returns:

the floating point value that correspond to the integer 0 in the image data.

See Also:

• getBScale()