Class ImageData

java.lang.Object
nom.tam.fits.Data
nom.tam.fits.ImageData
All Implemented Interfaces:
FitsElement
public class ImageData extends Data
This class instantiates FITS primary HDU and IMAGE extension data. Essentially these data are a primitive multi-dimensional array.

Starting in version 0.9 of the FITS library, this routine allows users to defer the reading of images if the FITS data is being read from a file. An ImageTiler object is supplied which can return an arbitrary subset of the image as a one dimensional array -- suitable for manipulation by standard Java libraries. A call to the getData() method will still return a multi-dimensional array, but the image data will not be read until the user explicitly requests. it.

  • Field Details

    • LOG

      private static final Logger LOG

    • byteSize

      private long byteSize
      The size of the data

    • dataArray

      private Object dataArray
      The actual array of data. This is normally a multi-dimensional primitive array. It may be null until the getData() routine is invoked, or it may be filled by during the read call when a non-random access device is used.

    • dataDescription

      private ImageData.ArrayDesc dataDescription
      A description of what the data should look like

    • tiler

      private StandardImageTiler tiler
      The image tiler associated with this image.

  • Constructor Details

    • ImageData

      public ImageData()
      Create the equivalent of a null data element.

    • ImageData

      public ImageData(Header h) throws FitsException
      Create an array from a header description. This is typically how data will be created when reading FITS data from a file where the header is read first. This creates an empty array.
      Parameters:
      h - header to be used as a template.
      Throws:
      FitsException - if there was a problem with the header description.

    • ImageData

      public ImageData(Object x)
      Create an ImageData object using the specified object to initialize the data array.
      Parameters:
      x - The initial data array. This should be a primitive array but this is not checked currently.

  • Method Details

    • getData

      public Object getData()
      Return the actual data. Note that this may return a null when the data is not readable. It might be better to throw a FitsException, but this is a very commonly called method and we prefered not to change how users must invoke it.
      Specified by:
      getData in class Data
      Returns:
      the data array object.

    • getTiler

      public StandardImageTiler getTiler()

    • read

      public void read(ArrayDataInput i) throws FitsException
      Description copied from interface: FitsElement
      Read a data array into the current object and if needed position to the beginning of the next FITS block.
      Specified by:
      read in interface FitsElement
      Specified by:
      read in class Data
      Parameters:
      i - The input data stream
      Throws:
      FitsException - if the read was unsuccessful.

    • setBuffer

      public void setBuffer(Buffer data)

    • write

      public void write(ArrayDataOutput o) throws FitsException
      Description copied from class: Data
      Write the data -- including any buffering needed
      Specified by:
      write in interface FitsElement
      Specified by:
      write in class Data
      Parameters:
      o - The output stream on which to write the data.
      Throws:
      FitsException - if the write was unsuccessful.

    • fillHeader

      protected void fillHeader(Header head) throws FitsException
      Fill header with keywords that describe image data.
      Specified by:
      fillHeader in class Data
      Parameters:
      head - The FITS header
      Throws:
      FitsException - if the object does not contain valid image data.

    • getTrueSize

      protected long getTrueSize()
      Get the size in bytes of the data
      Specified by:
      getTrueSize in class Data

    • parseHeader

      protected ImageData.ArrayDesc parseHeader(Header h) throws FitsException
      Throws:
      FitsException

    • setTiler

      void setTiler(StandardImageTiler tiler)