ncsa.hdf.object
Class ScalarDS

java.lang.Object
  ncsa.hdf.object.HObject
      ncsa.hdf.object.Dataset
          ncsa.hdf.object.ScalarDS

All Implemented Interfaces:

java.io.Serializable, DataFormat

Direct Known Subclasses:

FitsDataset, H4GRImage, H4SDS, H5ScalarDS, NC2Dataset

public abstract class ScalarDS
extends Dataset

A scalar dataset is a multiple dimension array of scalar points. The Datatype of a scalar dataset must be an atomic datatype. Common datatypes of scalar datasets include char, byte, short, int, long, float, double and string.

A ScalarDS can be an image or spreadsheet data. ScalarDS defines few methods to deal with both images and spreadsheets.

ScalarDS is an abstract class. Current implementing classes are the H4SDS, H5GRImage and H5ScalarDS.

Version:

1.1 9/4/2007

Author:

Peter X. Cao

See Also:

Serialized Form

Field Summary

static int	INTERLACE_LINE Indicates that each pixel component of RGB is stored as a scan line.
static int	INTERLACE_PIXEL Indicates that the pixel RGB values are contiguous.
static int	INTERLACE_PLANE Indicates that each pixel component of RGB is stored as a plane.
boolean	isFillValueConverted Flag to indicate if the FillValue is converted from unsigned C.

Fields inherited from class ncsa.hdf.object.HObject

separator, serialVersionUID

Constructor Summary

ScalarDS(FileFormat theFile, java.lang.String theName, java.lang.String thePath)
Constructs an instance of a ScalarDS with specific name and path.

ScalarDS(FileFormat theFile, java.lang.String theName, java.lang.String thePath, long[] oid)
Deprecated. Not for public use in the future.
Using ScalarDS(FileFormat, String, String)

Method Summary

void	clearData() Clears the data buffer in memory and to force the next read() to load data from file.
java.lang.Object	convertFromUnsignedC() Converts the data values of this dataset to appropriate Java integer if they are unsigned integers.
java.lang.Object	convertToUnsignedC() Converts Java integer data of this dataset back to unsigned C-type integer data if they are unsigned integers.
java.lang.Object	getFillValue() Returns the fill values for the dataset.
double[]	getImageDataRange() Returns the (min, max) pair of image data range.
int	getInterlace() Returns the interlace mode of a true color image (RGB).
abstract byte[][]	getPalette() Returns the palette of this scalar dataset or null if palette does not exist.
java.lang.String	getPaletteName(int idx) Get the name of a specific image palette from file.
abstract byte[]	getPaletteRefs() Returns the byte array of palette refs.
boolean	isDefaultImageOrder() Returns true if this dataset is displayed as an image with default image order.
boolean	isImage() Returns true if this dataset is an image.
boolean	isImageDisplay() Returns true if this dataset is displayed as an image.
boolean	isText() Returns true if this dataset is ASCII text.
boolean	isTrueColor() Returns true if this dataset is a true color image.
boolean	isUnsigned() Returns true if the original C data are unsigned integers.
abstract byte[][]	readPalette(int idx) Reads a specific image palette from file.
void	setIsImage(boolean b) Sets the flag to indicate this dataset is an image.
void	setIsImageDisplay(boolean b) Sets the flag to display the dataset as an image.
void	setPalette(byte[][] pal) Sets the palette for this dataset.

Methods inherited from class ncsa.hdf.object.Dataset

byteToString, clear, convertFromUnsignedC, convertFromUnsignedC, convertToUnsignedC, convertToUnsignedC, copy, getChunkSize, getCompression, getConvertByteToString, getData, getDatatype, getDimNames, getDims, getHeight, getMaxDims, getRank, getSelectedDims, getSelectedIndex, getSize, getStartDims, getStride, getWidth, init, isEnumConverted, isString, read, readBytes, setConvertByteToString, setData, setEnumConverted, stringToByte, write, write

Methods inherited from class ncsa.hdf.object.HObject

close, equalsOID, getFID, getFile, getFileFormat, getFullName, getLinkTargetObjName, getName, getOID, getPath, open, setLinkTargetObjName, setName, setPath, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface ncsa.hdf.object.DataFormat

getMetadata, hasAttribute, removeMetadata, writeMetadata

Field Detail

INTERLACE_PIXEL

public static final int INTERLACE_PIXEL

Indicates that the pixel RGB values are contiguous.

See Also:

Constant Field Values

INTERLACE_LINE

public static final int INTERLACE_LINE

Indicates that each pixel component of RGB is stored as a scan line.

See Also:

Constant Field Values

INTERLACE_PLANE

public static final int INTERLACE_PLANE

Indicates that each pixel component of RGB is stored as a plane.

See Also:

Constant Field Values

isFillValueConverted

public boolean isFillValueConverted

Flag to indicate if the FillValue is converted from unsigned C.

Constructor Detail

ScalarDS

public ScalarDS(FileFormat theFile,
                java.lang.String theName,
                java.lang.String thePath)

Constructs an instance of a ScalarDS with specific name and path. An HDF data object must have a name. The path is the group path starting from the root.

For example, in H5ScalarDS(h5file, "dset", "/arrays/"), "dset" is the name of the dataset, "/arrays" is the group path of the dataset.

Parameters:

theFile - the file that contains the data object.

theName - the name of the data object, e.g. "dset".

thePath - the full path of the data object, e.g. "/arrays/".

ScalarDS

@Deprecated
public ScalarDS(FileFormat theFile,
                           java.lang.String theName,
                           java.lang.String thePath,
                           long[] oid)

Deprecated. Not for public use in the future.
Using ScalarDS(FileFormat, String, String)

Method Detail

clearData

public void clearData()

Description copied from class: Dataset

Clears the data buffer in memory and to force the next read() to load data from file.

The function read() loads data from file into memory only if the data is not read. If data is already in memory, read() just returns the memory buffer. Sometimes we want to force read() to re-read data from file. For example, when the selection is changed, we need to re-read the data. clearData() clears the current memory buffer and force the read() to load the data from file.

Overrides:

clearData in class Dataset

See Also:

Dataset.getData(), Dataset.read()

convertFromUnsignedC

public java.lang.Object convertFromUnsignedC()

Converts the data values of this dataset to appropriate Java integer if they are unsigned integers.

Returns:

the converted data buffer.

See Also:

Dataset.convertToUnsignedC(Object), Dataset.convertFromUnsignedC(Object, Object)

convertToUnsignedC

public java.lang.Object convertToUnsignedC()

Converts Java integer data of this dataset back to unsigned C-type integer data if they are unsigned integers.

Returns:

the converted data buffer.

See Also:

Dataset.convertToUnsignedC(Object), Dataset.convertToUnsignedC(Object, Object), Dataset.convertFromUnsignedC(Object data_in)

getPalette

public abstract byte[][] getPalette()

Returns the palette of this scalar dataset or null if palette does not exist.

Scalar dataset can be displayed as spreadsheet data or image. When a scalar dataset is chosen to display as an image, the palette or color table may be needed to translate a pixel value to color components (for example, red, green, and blue). Some scalar datasets have no palette and some datasets have one or more than one palettes. If an associated palette exists but not loaded, this interface retrieves the palette from the file and returns the palette. If the palette is loaded, it returnd the palette. It returns null if there is no palette assciated with the dataset.

Current implementation only supports palette model of indexed RGB with 256 colors. Other models such as YUV", "CMY", "CMYK", "YCbCr", "HSV will be supported in the future.

The palette values are stored in a two-dimensional byte array and arrange by color components of red, green and blue. palette[][] = byte[3][256], where, palette[0][], palette[1][] and palette[2][] are the red, green and blue components respectively.

Sub-classes have to implement this interface. HDF4 and HDF5 images use different libraries to retrieve the associated palette.

Returns:

the 2D palette byte array.

setPalette

public final void setPalette(byte[][] pal)

Sets the palette for this dataset.

Parameters:

pal - the 2D palette byte array.

readPalette

public abstract byte[][] readPalette(int idx)

Reads a specific image palette from file.

A scalar dataset may have multiple palettes attached to it. readPalette(int idx) returns a specific palette identified by its index.

Parameters:

idx - the index of the palette to read.

getPaletteName

public java.lang.String getPaletteName(int idx)

Get the name of a specific image palette from file.

A scalar dataset may have multiple palettes attached to it. getPaletteName(int idx) returns the name of a specific palette identified by its index.

Parameters:

idx - the index of the palette to retrieve the name.

Returns:

The name of the palette

getPaletteRefs

public abstract byte[] getPaletteRefs()

Returns the byte array of palette refs.

A palette reference is an object reference that points to the palette dataset.

For example, Dataset "Iceberg" has an attribute of object reference "Palette". The arrtibute "Palette" has value "2538" that is the object reference of the palette data set "Iceberg Palette".

Returns:

null if there is no palette attribute attached to this dataset.

isImage

public final boolean isImage()

Returns true if this dataset is an image.

For all Images, they must have an attribute called "CLASS". The value of this attribute is "IMAGE". For more details, read HDF5 Image and Palette Specification

Returns:

true if the dataset is an image; otherwise, returns false.

isImageDisplay

public final boolean isImageDisplay()

Returns true if this dataset is displayed as an image.

A ScalarDS can be displayed as an image or table.

Returns:

true if this dataset is displayed as an image; otherwise, returns false.

isDefaultImageOrder

public final boolean isDefaultImageOrder()

Returns true if this dataset is displayed as an image with default image order.

A ScalarDS can be displayed as an image with different orders of dimensions.

Returns:

true if this dataset is displayed as an image with default image order; otherwise, returns false.

setIsImageDisplay

public final void setIsImageDisplay(boolean b)

Sets the flag to display the dataset as an image.

Parameters:

b - if b is true, display the dataset as an image

setIsImage

public final void setIsImage(boolean b)

Sets the flag to indicate this dataset is an image.

Parameters:

b - if b is true, the dataset is an image.

isTrueColor

public final boolean isTrueColor()

Returns true if this dataset is a true color image.

isText

public final boolean isText()

Returns true if this dataset is ASCII text.

Returns:

true if this dataset is ASCII text.

getInterlace

public final int getInterlace()

Returns the interlace mode of a true color image (RGB). Valid values:

     INTERLACE_PIXEL -- RGB components are contiguous, i.e. rgb, rgb, rgb, ...
     INTERLACE_LINE -- each RGB component is stored as a scan line
     INTERLACE_PLANE -- each RGB component is stored as a plane
 

Returns:

the interlace mode of a true color image (RGB).

isUnsigned

public final boolean isUnsigned()

Returns true if the original C data are unsigned integers.

Returns:

true if the original C data are unsigned integers.

getImageDataRange

public double[] getImageDataRange()

Returns the (min, max) pair of image data range.

Returns:

the (min, max) pair of image data range.

getFillValue

public final java.lang.Object getFillValue()

Returns the fill values for the dataset.

Returns:

the fill values for the dataset.