view
Class GIFEncoder

java.lang.Object
  view.GIFEncoder

public class GIFEncoder
extends Object

GIFEncoder is a class which takes an image and saves it to a stream using the GIF file format (Graphics Interchange Format). A GIFEncoder is constructed with either an AWT Image (which must be fully loaded) or a set of RGB arrays. The image can be written out with a call to Write.

Three caveats:

• GIFEncoder will convert the image to indexed color upon construction. This will take some time, depending on the size of the image. Also, actually writing the image out (Write) will take time.

• The image cannot have more than 256 colors, since GIF is an 8 bit format. For a 24 bit to 8 bit quantization algorithm, see Graphics Gems II III.2 by Xialoin Wu. Or check out his C source.

• Since the image must be completely loaded into memory, GIFEncoder may have problems with large images. Attempting to encode an image which will not fit into memory will probably result in the following exception:

  java.awt.AWTException: Grabber returned false: 192

GIFEncoder is based upon gifsave.c, which was written and released by:

Sverre H. Huseby
Bjoelsengt. 17
N-0468 Oslo
Norway

Phone: +47 2 230539
sverrehu@ifi.uio.no

Field Summary

(package private) byte[]	colors_
(package private) short	height_
(package private) ImageDescriptor	id_
(package private) int	numColors_
(package private) byte[]	pixels_
(package private) ScreenDescriptor	sd_
(package private) short	width_

Constructor Summary

GIFEncoder(byte[][] r, byte[][] g, byte[][] b)

GIFEncoder(Image image)

Method Summary

(package private) void	ToIndexedColor(byte[][] r, byte[][] g, byte[][] b)
void	Write(OutputStream output)

Methods inherited from class java.lang.Object

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

Field Detail

width_

short width_

height_

short height_

numColors_

int numColors_

pixels_

byte[] pixels_

colors_

byte[] colors_

sd_

ScreenDescriptor sd_

id_

ImageDescriptor id_

Constructor Detail

GIFEncoder

public GIFEncoder(Image image)
           throws AWTException

Parameters:

image -

Throws:

AWTException

GIFEncoder

public GIFEncoder(byte[][] r,
                  byte[][] g,
                  byte[][] b)
           throws AWTException

Parameters:

r -

g -

b -

Throws:

AWTException

Method Detail

Write

public void Write(OutputStream output)
           throws IOException

Parameters:

output -

Throws:

IOException

ToIndexedColor

void ToIndexedColor(byte[][] r,
                    byte[][] g,
                    byte[][] b)
              throws AWTException

Parameters:

r -

g -

b -

Throws:

AWTException