com.threerings.media.image

Class Quantize

java.lang.Object

com.threerings.media.image.Quantize

public class Quantize
extends Object

Calculates a reduced color Three Rings note: Code taken from Adam Doppelt, who adapted it from other code. Feel the love.

RenderingHints is supposed to provide a way to block dithering, but I have not been able to get that to work. It always dithers, so we use this class instead.

The following modifications were added to the original code: - Made it work with image data with transparent pixels. - Clarified documentation of the main method. - Changed the 'QUICK' constant to false for better quantization. - Fixed an integer overflow that caused a bug quantizing large images.

Original headers follow: An efficient color quantization algorithm, adapted from the C++ implementation quantize.c in ImageMagick. The pixels for an image are placed into an oct tree. The oct tree is reduced in size, and the pixels from the original image are reassigned to the nodes in the reduced tree.

Here is the copyright notice from ImageMagick:

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Version:

0.90 19 Sep 2000

Author:

Adam Doppelt

Constructor Summary

Constructors

Constructor and Description
Quantize()

Method Summary

Modifier and Type	Method and Description
static int[]	quantizeImage(int[][] pixels, int max_colors) Reduce the image to the given number of colors.

Methods inherited from class java.lang.Object

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

Constructor Detail

Quantize

public Quantize()

Method Detail

quantizeImage

public static int[] quantizeImage(int[][] pixels,
                                  int max_colors)

Reduce the image to the given number of colors.

Parameters:

pixels - an in/out parameter that should initially contain [A]RGB values but that will contain color palette indicies upon return.

Returns:

The new color palette.