com.lowagie.text.pdf.codec
Class GifImage

java.lang.Object
  com.lowagie.text.pdf.codec.GifImage

public class GifImage
extends java.lang.Object

Reads gif images of all types. All the images in a gif are read in the constructors and can be retrieved with other methods.

Author:

Paulo Soares (psoares@consiste.pt)

Field Summary

protected int	bgColor
protected int	bgIndex
protected byte[]	block
protected int	blockSize
protected int	delay
protected int	dispose
protected java.util.ArrayList	frames
protected byte[]	fromData
protected java.net.URL	fromUrl
protected boolean	gctFlag
protected int	height
protected int	ih
protected java.io.DataInputStream	in
protected boolean	interlace
protected int	iw
protected int	ix
protected int	iy
protected boolean	lctFlag
protected int	lctSize
protected int	m_bpc
protected byte[]	m_curr_table
protected int	m_gbpc
protected byte[]	m_global_table
protected int	m_line_stride
protected byte[]	m_local_table
protected byte[]	m_out
protected static int	MaxStackSize
protected int	pixelAspect
protected byte[]	pixels
protected byte[]	pixelStack
protected short[]	prefix
protected byte[]	suffix
protected int	transIndex
protected boolean	transparency
protected int	width

Constructor Summary

GifImage(byte[] data)
Reads gif images from a byte array.

GifImage(java.io.InputStream is)
Reads gif images from a stream.

GifImage(java.lang.String file)
Reads gif images from a file.

GifImage(java.net.URL url)
Reads gif images from an URL.

Method Summary

protected boolean	decodeImageData()
int	getFrameCount() Gets the number of frames the gif has.
int[]	getFramePosition(int frame) Gets the [x,y] position of the frame in reference to the logical screen.
Image	getImage(int frame) Gets the image from a frame.
int[]	getLogicalScreen() Gets the logical screen.
protected static int	newBpc(int bpc)
protected int	readBlock() Reads next variable length block from input.
protected byte[]	readColorTable(int bpc)
protected void	readContents()
protected void	readGraphicControlExt() Reads Graphics Control Extension values
protected void	readHeader() Reads GIF file header information.
protected void	readImage() Reads next frame image
protected void	readLSD() Reads Logical Screen Descriptor
protected int	readShort() Reads next 16-bit value, LSB first
protected void	resetFrame() Resets frame state for reading next image.
protected void	setPixel(int x, int y, int v)
protected void	skip() Skips variable length blocks up to and including next zero length block.

Methods inherited from class java.lang.Object

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

Field Detail

in

protected java.io.DataInputStream in

width

protected int width

height

protected int height

gctFlag

protected boolean gctFlag

bgIndex

protected int bgIndex

bgColor

protected int bgColor

pixelAspect

protected int pixelAspect

lctFlag

protected boolean lctFlag

interlace

protected boolean interlace

lctSize

protected int lctSize

ix

protected int ix

iy

protected int iy

iw

protected int iw

ih

protected int ih

block

protected byte[] block

blockSize

protected int blockSize

dispose

protected int dispose

transparency

protected boolean transparency

delay

protected int delay

transIndex

protected int transIndex

MaxStackSize

protected static final int MaxStackSize

See Also:

Constant Field Values

prefix

protected short[] prefix

suffix

protected byte[] suffix

pixelStack

protected byte[] pixelStack

pixels

protected byte[] pixels

m_out

protected byte[] m_out

m_bpc

protected int m_bpc

m_gbpc

protected int m_gbpc

m_global_table

protected byte[] m_global_table

m_local_table

protected byte[] m_local_table

m_curr_table

protected byte[] m_curr_table

m_line_stride

protected int m_line_stride

fromData

protected byte[] fromData

fromUrl

protected java.net.URL fromUrl

frames

protected java.util.ArrayList frames

Constructor Detail

GifImage

public GifImage(java.net.URL url)
         throws java.io.IOException

Reads gif images from an URL.

Parameters:

url - the URL

Throws:

java.io.IOException - on error

GifImage

public GifImage(java.lang.String file)
         throws java.io.IOException

Reads gif images from a file.

Parameters:

file - the file

Throws:

java.io.IOException - on error

GifImage

public GifImage(byte[] data)
         throws java.io.IOException

Reads gif images from a byte array.

Parameters:

data - the byte array

Throws:

java.io.IOException - on error

GifImage

public GifImage(java.io.InputStream is)
         throws java.io.IOException

Reads gif images from a stream. The stream is not closed.

Parameters:

is - the stream

Throws:

java.io.IOException - on error

Method Detail

getFrameCount

public int getFrameCount()

Gets the number of frames the gif has.

Returns:

the number of frames the gif has

getImage

public Image getImage(int frame)

Gets the image from a frame. The first frame is 1.

Parameters:

frame - the frame to get the image from

Returns:

the image

getFramePosition

public int[] getFramePosition(int frame)

Gets the [x,y] position of the frame in reference to the logical screen.

Parameters:

frame - the frame

Returns:

the [x,y] position of the frame

getLogicalScreen

public int[] getLogicalScreen()

Gets the logical screen. The images may be smaller and placed in some position in this screen to playback some animation. No image will be be bigger that this.

Returns:

the logical screen dimensions as [x,y]

readHeader

protected void readHeader()
                   throws java.io.IOException

Reads GIF file header information.

Throws:

java.io.IOException

readLSD

protected void readLSD()
                throws java.io.IOException

Reads Logical Screen Descriptor

Throws:

java.io.IOException

readShort

protected int readShort()
                 throws java.io.IOException

Reads next 16-bit value, LSB first

Throws:

java.io.IOException

readBlock

protected int readBlock()
                 throws java.io.IOException

Reads next variable length block from input.

Returns:

number of bytes stored in "buffer"

Throws:

java.io.IOException

readColorTable

protected byte[] readColorTable(int bpc)
                         throws java.io.IOException

Throws:

java.io.IOException

newBpc

protected static int newBpc(int bpc)

readContents

protected void readContents()
                     throws java.io.IOException

Throws:

java.io.IOException

readImage

protected void readImage()
                  throws java.io.IOException

Reads next frame image

Throws:

java.io.IOException

decodeImageData

protected boolean decodeImageData()
                           throws java.io.IOException

Throws:

java.io.IOException

setPixel

protected void setPixel(int x,
                        int y,
                        int v)

resetFrame

protected void resetFrame()

Resets frame state for reading next image.

readGraphicControlExt

protected void readGraphicControlExt()
                              throws java.io.IOException

Reads Graphics Control Extension values

Throws:

java.io.IOException

skip

protected void skip()
             throws java.io.IOException

Skips variable length blocks up to and including next zero length block.

Throws:

java.io.IOException