Class DataBlk

  • Direct Known Subclasses:
    DataBlkFloat, DataBlkInt

    public abstract class DataBlk
    extends Object
    This is a generic abstract class to store data from a block of an image. This class does not have the notion of components. Therefore, it should be used for data from a single component. Subclasses should implement the different types of storage (int, float, etc.).

    The data is always stored in one array, of the type matching the data type (i.e. for 'int' it's an 'int[]'). The data should be stored in the array in standard scan-line order. That is the samples go from the top-left corner of the code-block to the lower-right corner by line and then column.

    The member variable 'offset' gives the index in the array of the first data element (i.e. the top-left coefficient (ulx,uly)). The member variable 'scanw' gives the width of the scan that is used to store the data, that can be different from the width of the block. Element '(x,y)' of the code-block (i.e. '(ulx,uly)' is the top-left coefficient), will appear at position 'offset+(y-uly)*scanw+(x-ulx)' in the array of data.

    A block of data can have the progressive attribute set. Data is progressive when it is obtained by successive refinement and the values in this block are approximations of the "final" values. When the final values are returned the progressive attribute must be turned off.

    The classes DataBlkInt and DataBlkFloat provide implementations for int and float types respectively.

    See Also:
    DataBlkInt, DataBlkFloat
    • Field Summary

      Fields 
      Modifier and Type Field Description
      int h
      The height of the block, in pixels.
      int offset
      The offset in the array of the top-left coefficient
      boolean progressive
      The progressive attribute (false by default)
      int scanw
      The width of the scanlines used to store the data in the array
      static int TYPE_BYTE
      The identifier for the byte data type, as signed 8 bits.
      static int TYPE_FLOAT
      The identifier for the float data type
      static int TYPE_INT
      The identifier for the int data type, as signed 32 bits.
      static int TYPE_SHORT
      The identifier for the short data type, as signed 16 bits.
      int ulx
      The horizontal coordinate (in pixels) of the upper-left corner of the block of data.
      int uly
      The vertical coordinate of the upper-left corner of the block of data.
      int w
      The width of the block, in pixels.
    • Constructor Summary

      Constructors 
      Constructor Description
      DataBlk()  
    • Field Detail

      • TYPE_BYTE

        public static final int TYPE_BYTE
        The identifier for the byte data type, as signed 8 bits.
        See Also:
        Constant Field Values
      • TYPE_SHORT

        public static final int TYPE_SHORT
        The identifier for the short data type, as signed 16 bits.
        See Also:
        Constant Field Values
      • TYPE_INT

        public static final int TYPE_INT
        The identifier for the int data type, as signed 32 bits.
        See Also:
        Constant Field Values
      • TYPE_FLOAT

        public static final int TYPE_FLOAT
        The identifier for the float data type
        See Also:
        Constant Field Values
      • ulx

        public int ulx
        The horizontal coordinate (in pixels) of the upper-left corner of the block of data. This is relative to the component of the image from where this block was filled or is to be filled.
      • uly

        public int uly
        The vertical coordinate of the upper-left corner of the block of data. This is relative to the component of the image from where this block was filled or is to be filled.
      • w

        public int w
        The width of the block, in pixels.
      • h

        public int h
        The height of the block, in pixels.
      • offset

        public int offset
        The offset in the array of the top-left coefficient
      • scanw

        public int scanw
        The width of the scanlines used to store the data in the array
      • progressive

        public boolean progressive
        The progressive attribute (false by default)
    • Constructor Detail

      • DataBlk

        public DataBlk()
    • Method Detail

      • getSize

        public static int getSize​(int type)
        Returns the size in bits, given the data type. The data type must be one defined in this class. An IllegalArgumentException is thrown if type is not defined in this class.
        Parameters:
        type - The data type.
        Returns:
        The size in bits of the data type.
      • getDataType

        public abstract int getDataType()
        Returns the data type of the DataBlk object, as defined in this class.
        Returns:
        The data type of the object, as defined in thsi class.
      • getData

        public abstract Object getData()
        Returns the array containing the data, or null if there is no data. The returned array is of the type returned by getDataType() (e.g., for TYPE_INT, it is a int[]).

        Each implementing class should provide a type specific equivalent method (e.g., getDataInt() in DataBlkInt) which returns an array of the correct type explicetely and not through an Object.

        Returns:
        The array containing the data, or null if there is no data.
        See Also:
        getDataType()
      • setData

        public abstract void setData​(Object arr)
        Sets the data array to the specified one. The type of the specified data array must match the one returned by getDataType() (e.g., for TYPE_INT, it should be a int[]). If the wrong type of array is given a ClassCastException will be thrown.

        The size of the array is not necessarily checked for consistency with w and h or any other fields.

        Each implementing class should provide a type specific equivalent method (e.g., setDataInt() in DataBlkInt) which takes an array of the correct type explicetely and not through an Object.

        Parameters:
        arr - The new data array to use
        See Also:
        getDataType()
      • toString

        public String toString()
        Returns a string of informations about the DataBlk
        Overrides:
        toString in class Object
        Returns:
        Block dimensions and progressiveness in a string