How to use ColorQuantizerDescriptor?

Question

Following the @PhiLho idea , the answer to How to convert a BufferedImage to 8 bits? , I want to use ColorQuantizerDescriptor to convert BufferedImage , imageType TYPE_INT_RGB, but RenderedOp # getColorModel () throws the following exception:

 java.lang.IllegalArgumentException: The specified ColorModel is incompatible with the image SampleModel.
     at javax.media.jai.PlanarImage.setImageLayout (PlanarImage.javahaps41)
     at javax.media.jai.RenderedOp.createRendering (RenderedOp.java:878)
     at javax.media.jai.RenderedOp.getColorModel (RenderedOp.java:2253)

This is the code I'm trying to use:

 final RenderedOp medianCutQuantizerOp = ColorQuantizerDescriptor.create(rgbImage, ColorQuantizerDescriptor.MEDIANCUT, 256, null, null, null, null, null); final BufferedImage bi = medianCutQuantizerOp.getAsBufferedImage(null, medianCutQuantizerOp.getColorModel()); 

How to use ColorQuantizerDescriptor ?

Answer 1

The following example has been modified from http://code.google.com/p/color-reduction-experiments/source/browse/trunk/it/geosolutions/mapproducers/MapProducersTest.java?r=2

 public class Main { public static void main(String[] args) throws Exception { BufferedImage original = ImageIO.read(new File("/Users/Nick/Desktop/with_flowers.jpg")); // 300 seems to be a good number final RenderedOp cqImage = ColorQuantizerDescriptor.create( original, ColorQuantizerDescriptor.OCTTREE, new Integer(255), new Integer(300), null, new Integer(2), new Integer(2), null); assert cqImage.getColorModel() instanceof IndexColorModel; final BufferedImage converted = cqImage.getAsBufferedImage(); SwingUtilities.invokeLater(new Runnable() { public void run() { final JFrame f = new JFrame(); f.setTitle("Test"); f.getContentPane().add((new ScrollingImagePanel(converted, 300, 300))); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.pack(); f.setVisible(true); } }); } } 

Works for me:

Edit: I tried the midline incision and it seems to work, albeit a lot slower.