Class GIFEncoder

java.lang.Object
  |
  +--GIFEncoder

public class GIFEncoder

extends java.lang.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
• The class was modified to constuct with Ury Segal's BMP class, and it works faster that way

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

Constructor Summary

GIFEncoder(java.awt.Image image)

Method Summary

static void	saveGIF(java.awt.Image im, java.lang.String name)
void	Write(java.io.OutputStream output) Writes the image out to a stream in the GIF file format.

Methods inherited from class java.lang.Object

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

Constructor Detail

GIFEncoder

public GIFEncoder(java.awt.Image image)
           throws java.awt.AWTException

Method Detail

saveGIF

public static void saveGIF(java.awt.Image im,
                           java.lang.String name)

Write

public void Write(java.io.OutputStream output)
           throws java.io.IOException

Writes the image out to a stream in the GIF file format. This will be a single GIF87a image, non-interlaced, with no background color.

java.io.IOException