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[SOLVED] Image.getColor() not working after scaling image
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Author:  n0xew [ Thu Aug 15, 2013 11:53 pm ]
Post subject:  [SOLVED] Image.getColor() not working after scaling image

EDIT : I figured out a (not very proper I must admit) way to solve the solution, see at the end of this post for code & explanations :)


I'm having an issue that has already been posted (but without fix), so I'm reposting it. It happens when with a resized Image(with .getScaledCopy(width,height) method) I call getColor(x,y) method; it seems to return the Color at (x,y) position of the very first (non resized) image.
I'm sorry I don't have precise code for it as it's really messy, maybe this image will help understanding :

To get those pictures i've drawn the image, then with a messy method i generate a polygon that approaches the "true" borders of the picture (transparent pixel excluded), and i draw it. Here we go :

-non resized image :

-resized image :

-resized image, and copy of the image by the following code :
Image img = new Image(imageToConvert.getTexture());


So if someone could help me for this, i'll be really grateful!

PS : i know, my green color is pretty ugly, was just for testing ;)

I figured out how to solve this problem in a not proper way which is converting my image to a bufferedImage, scale it and convert it back. I've been using some various codes I found on various forums. It may not be optimal but it works, so it's okay with me ^^
Here is how I call my method :
Image scaledImage = new Image("data/images/BoatsSets/0/Up.png");
      scaledImage  = resizeImage(scaledImage, 50, 100);

And here is the used methods. As i said, it may be not be optimal and if someone has a better way I would totally use it!

   private static Image resizeImage(Image originalImage, int newWidth, int newHeight){
      int type = BufferedImage.TYPE_INT_ARGB;
      BufferedImage originalBufferedImage = toBufferedImage(originalImage, true);
      java.awt.Image image = originalBufferedImage.getScaledInstance(newWidth, newHeight, java.awt.Image.SCALE_SMOOTH);
      BufferedImage buffered = new BufferedImage(newWidth, newHeight, type);
      buffered.getGraphics().drawImage(image, 0, 0 , null);
      BufferedImage b = new BufferedImage(buffered.getWidth(null),buffered.getHeight(null),BufferedImage.TYPE_INT_ARGB);
      ImageBuffer buf = new ImageBuffer(b.getWidth(),b.getHeight());
      int x,y,rgb;
      for (y = 0;y < b.getHeight();y++) {
         for (x = 0;x < b.getWidth();x++) {
            rgb = b.getRGB(x,y);
      return buf.getImage();
   private static java.awt.image.BufferedImage toBufferedImage(org.newdawn.slick.Image image, boolean hasAlpha) {
      // conver the image into a byte buffer by reading each pixel in turn
      int len = 4 * image.getWidth() * image.getHeight();
      if (!hasAlpha) {
         len = 3 * image.getWidth() * image.getHeight();

      ByteBuffer out = ByteBuffer.allocate(len);
      org.newdawn.slick.Color c;

      for (int y = 0; y < image.getHeight(); y++) {
         for (int x = 0; x<image.getWidth(); x++) {
            c = image.getColor(x, y);

            out.put((byte) (c.r * 255.0f));
            out.put((byte) (c.g * 255.0f));
            out.put((byte) (c.b * 255.0f));
            if (hasAlpha) {
               out.put((byte) (c.a * 255.0f));

      // create a raster of the correct format and fill it with our buffer
      DataBufferByte dataBuffer = new DataBufferByte(out.array(), len);

      PixelInterleavedSampleModel sampleModel;

      ColorModel cm;

      if (hasAlpha) {
         int[] offsets = { 0, 1, 2, 3 };
         sampleModel = new PixelInterleavedSampleModel(
               DataBuffer.TYPE_BYTE, image.getWidth(), image.getHeight(), 4,
               4 * image.getWidth(), offsets);

         cm = new ComponentColorModel(ColorSpace
               .getInstance(ColorSpace.CS_sRGB), new int[] { 8, 8, 8, 8 },
               true, false, ComponentColorModel.TRANSLUCENT,
      } else {
         int[] offsets = { 0, 1, 2};
         sampleModel = new PixelInterleavedSampleModel(
               DataBuffer.TYPE_BYTE, image.getWidth(), image.getHeight(), 3,
               3 * image.getWidth(), offsets);

         cm = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
               new int[] {8,8,8,0},
      WritableRaster raster = Raster.createWritableRaster(sampleModel, dataBuffer, new Point(0, 0));

      // finally create the buffered image based on the data from the texture
      // and spit it through to ImageIO
      return new BufferedImage(cm, raster, false, null);       

Hope this helps some people!

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