C# 클래스 CSJ2K.j2k.image.input.ImgReaderPGM

This class implements the ImgData interface for reading 8 bit unsigned data from a binary PGM file.

After being read the coefficients are level shifted by subtracting 2^(nominal bit range-1)

The TransferType (see ImgData) of this class is TYPE_INT.

NOTE: This class is not thread safe, for reasons of internal buffering.

상속: ImgReader

공개 프로퍼티들

프로퍼티	타입	설명
DC_OFFSET	int

공개 메소드들

메소드	설명
ImgReaderPGM ( IFileInfo file ) : System	Creates a new PGM file reader from the specified file.
ImgReaderPGM ( System fname ) : System	Creates a new PGM file reader from the specified file name.
ToString ( ) : System.String	Returns a string of information about the object, more than 1 line long. The information string includes information from the underlying RandomAccessIO (its toString() method is called in turn).
close ( ) : void	Closes the underlying RandomAccessFile from where the image data is being read. No operations are possible after a call to this method.
getCompData ( CSJ2K.j2k.image.DataBlk blk, int c ) : CSJ2K.j2k.image.DataBlk	Returns, in the blk argument, a block of image data containing the specifed rectangular area, in the specified component. The data is returned, as a copy of the internal data, therefore the returned data can be modified "in place". After being read the coefficients are level shifted by subtracting 2^(nominal bit range - 1) The rectangular area to return is specified by the 'ulx', 'uly', 'w' and 'h' members of the 'blk' argument, relative to the current tile. These members are not modified by this method. The 'offset' of the returned data is 0, and the 'scanw' is the same as the block's width. See the 'DataBlk' class. If the data array in 'blk' is 'null', then a new one is created. If the data array is not 'null' then it is reused, and it must be large enough to contain the block's data. Otherwise an 'ArrayStoreException' or an 'IndexOutOfBoundsException' is thrown by the Java system. The returned data has its 'progressive' attribute unset (i.e. false). This method just calls 'getInternCompData(blk, n)'. When an I/O exception is encountered the JJ2KExceptionHandler is used. The exception is passed to its handleException method. The action that is taken depends on the action that has been registered in JJ2KExceptionHandler. See JJ2KExceptionHandler for details.
getFixedPoint ( int c ) : int	Returns the position of the fixed point in the specified component (i.e. the number of fractional bits), which is always 0 for this ImgReader.
getInternCompData ( CSJ2K.j2k.image.DataBlk blk, int c ) : CSJ2K.j2k.image.DataBlk	Returns, in the blk argument, the block of image data containing the specifed rectangular area, in the specified component. The data is returned, as a reference to the internal data, if any, instead of as a copy, therefore the returned data should not be modified. After being read the coefficients are level shifted by subtracting 2^(nominal bit range - 1) The rectangular area to return is specified by the 'ulx', 'uly', 'w' and 'h' members of the 'blk' argument, relative to the current tile. These members are not modified by this method. The 'offset' and 'scanw' of the returned data can be arbitrary. See the 'DataBlk' class. If the data array in `blk` is `null`, then a new one is created if necessary. The implementation of this interface may choose to return the same array or a new one, depending on what is more efficient. Therefore, the data array in `blk` prior to the method call should not be considered to contain the returned data, a new array may have been created. Instead, get the array from `blk` after the method has returned. The returned data always has its 'progressive' attribute unset (i.e. false). When an I/O exception is encountered the JJ2KExceptionHandler is used. The exception is passed to its handleException method. The action that is taken depends on the action that has been registered in JJ2KExceptionHandler. See JJ2KExceptionHandler for details.
getNomRangeBits ( int c ) : int	Returns the number of bits corresponding to the nominal range of the data in the specified component. This is the value rb (range bits) that was specified in the constructor, which normally is 8 for non bilevel data, and 1 for bilevel data. If this number is b then the nominal range is between -2^(b-1) and 2^(b-1)-1, since unsigned data is level shifted to have a nominal average of 0.
isOrigSigned ( int c ) : bool	Returns true if the data read was originally signed in the specified component, false if not. This method returns always false since PGM data is always unsigned.

비공개 메소드들

메소드	설명
confirmFileType ( ) : void	Checks that the RandomAccessIO begins with 'P5'
countedByteRead ( ) : byte	Returns a byte read from the RandomAccessIO. The number of read byted are counted to keep track of the offset of the pixel data in the PGM file
readHeaderInt ( ) : int	Returns an int read from the header of the PGM file.
skipCommentAndWhiteSpace ( ) : void	Skips any line in the header starting with '#' and any space, tab, line feed or carriage return.

메소드 상세

ImgReaderPGM() 공개 메소드

Creates a new PGM file reader from the specified file.

If an error occurs while opening the file. /// ///

public ImgReaderPGM ( IFileInfo file ) : System
file	IFileInfo	The input file. /// ///
리턴	System

ImgReaderPGM() 공개 메소드

Creates a new PGM file reader from the specified file name.

If an error occurs while opening the file. /// ///

public ImgReaderPGM ( System fname ) : System
fname	System	The input file name. /// ///
리턴	System

ToString() 공개 메소드

Returns a string of information about the object, more than 1 line long. The information string includes information from the underlying RandomAccessIO (its toString() method is called in turn).

public ToString ( ) : System.String
리턴	System.String

close() 공개 메소드

Closes the underlying RandomAccessFile from where the image data is being read. No operations are possible after a call to this method.

If an I/O error occurs. /// ///

public close ( ) : void
리턴	void

getCompData() 공개 메소드

Returns, in the blk argument, a block of image data containing the specifed rectangular area, in the specified component. The data is returned, as a copy of the internal data, therefore the returned data can be modified "in place".

After being read the coefficients are level shifted by subtracting 2^(nominal bit range - 1)

The rectangular area to return is specified by the 'ulx', 'uly', 'w' and 'h' members of the 'blk' argument, relative to the current tile. These members are not modified by this method. The 'offset' of the returned data is 0, and the 'scanw' is the same as the block's width. See the 'DataBlk' class.

If the data array in 'blk' is 'null', then a new one is created. If the data array is not 'null' then it is reused, and it must be large enough to contain the block's data. Otherwise an 'ArrayStoreException' or an 'IndexOutOfBoundsException' is thrown by the Java system.

The returned data has its 'progressive' attribute unset (i.e. false).

This method just calls 'getInternCompData(blk, n)'.

When an I/O exception is encountered the JJ2KExceptionHandler is used. The exception is passed to its handleException method. The action that is taken depends on the action that has been registered in JJ2KExceptionHandler. See JJ2KExceptionHandler for details.

public getCompData ( CSJ2K.j2k.image.DataBlk blk, int c ) : CSJ2K.j2k.image.DataBlk
blk	CSJ2K.j2k.image.DataBlk	Its coordinates and dimensions specify the area to /// return. If it contains a non-null data array, then it must have the /// correct dimensions. If it contains a null data array a new one is /// created. The fields in this object are modified to return the data. /// ///
c	int	The index of the component from which to get the data. Only 0 /// is valid. /// ///
리턴	CSJ2K.j2k.image.DataBlk

getFixedPoint() 공개 메소드

Returns the position of the fixed point in the specified component (i.e. the number of fractional bits), which is always 0 for this ImgReader.

public getFixedPoint ( int c ) : int
c	int	The index of the component. /// ///
리턴	int

getInternCompData() 공개 메소드

Returns, in the blk argument, the block of image data containing the specifed rectangular area, in the specified component. The data is returned, as a reference to the internal data, if any, instead of as a copy, therefore the returned data should not be modified.

After being read the coefficients are level shifted by subtracting 2^(nominal bit range - 1)

The rectangular area to return is specified by the 'ulx', 'uly', 'w' and 'h' members of the 'blk' argument, relative to the current tile. These members are not modified by this method. The 'offset' and 'scanw' of the returned data can be arbitrary. See the 'DataBlk' class.

If the data array in blk is null, then a new one is created if necessary. The implementation of this interface may choose to return the same array or a new one, depending on what is more efficient. Therefore, the data array in blk prior to the method call should not be considered to contain the returned data, a new array may have been created. Instead, get the array from blk after the method has returned.

The returned data always has its 'progressive' attribute unset (i.e. false).

public getInternCompData ( CSJ2K.j2k.image.DataBlk blk, int c ) : CSJ2K.j2k.image.DataBlk
blk	CSJ2K.j2k.image.DataBlk	Its coordinates and dimensions specify the area to /// return. Some fields in this object are modified to return the data. /// ///
c	int	The index of the component from which to get the data. Only 0 /// is valid. /// ///
리턴	CSJ2K.j2k.image.DataBlk

getNomRangeBits() 공개 메소드

Returns the number of bits corresponding to the nominal range of the data in the specified component. This is the value rb (range bits) that was specified in the constructor, which normally is 8 for non bilevel data, and 1 for bilevel data.

If this number is b then the nominal range is between -2^(b-1) and 2^(b-1)-1, since unsigned data is level shifted to have a nominal average of 0.

public getNomRangeBits ( int c ) : int

c int The index of the component. /// ///

리턴 int

isOrigSigned() 공개 메소드

Returns true if the data read was originally signed in the specified component, false if not. This method returns always false since PGM data is always unsigned.

public isOrigSigned ( int c ) : bool

c int The index of the component, from 0 to N-1. /// ///

리턴 bool

프로퍼티 상세

DC_OFFSET 공개적으로 정적으로 프로퍼티

DC offset value used when reading image

public static int DC_OFFSET

리턴 int

public getNomRangeBits ( int c ) : int
c	int	The index of the component. /// ///
리턴	int

public isOrigSigned ( int c ) : bool
c	int	The index of the component, from 0 to N-1. /// ///
리턴	bool