import javax.media.jai.operator.ScaleDescriptor; //导入依赖的package包/类
public static BufferedImage getScaledImage(RenderedImage image, float scale) {

        RenderedOp renderedOp = ScaleDescriptor.create(image, scale, scale,
                new Float(0.0f), new Float(0.0f), Interpolation.getInstance(Interpolation.INTERP_NEAREST), null);
        return renderedOp.getRendering().getAsBufferedImage();

		/*
		ParameterBlock pb = new ParameterBlock();
		pb.addSource(image); // The source image
		pb.add((double)scale); // The xScale
		pb.add((double)scale); // The yScale
		pb.add(0.0); // The x translation
		pb.add(0.0); // The y translation
 
		RenderingHints qualityHints = new RenderingHints(RenderingHints.KEY_RENDERING,
			    RenderingHints.VALUE_RENDER_QUALITY);
		RenderedOp resizedImage = JAI.create("SubsampleAverage", pb, qualityHints);
		return resizedImage.getAsBufferedImage();
		*/
    }
 

import javax.media.jai.operator.ScaleDescriptor; //导入依赖的package包/类
@Override
protected Image doInBackground() throws Exception {
    RenderedImage sourceImage = FileLoadDescriptor.create(imageFilePath, null, true, null);
    int width = sourceImage.getWidth();
    int height = sourceImage.getHeight();

    float scale = (float) (targetDimension.getWidth() / width);
    scale = (float) Math.min(scale, targetDimension.getHeight() / height);
    if (scale > 1) {
        scale = 1.0f;
    }

    Interpolation interpolation = Interpolation.getInstance(Interpolation.INTERP_NEAREST);
    RenderedImage scaledImage = ScaleDescriptor.create(sourceImage,
                                                       scale, scale,
                                                       0.0f, 0.0f,
                                                       interpolation, null);
    PlanarImage planarImage = PlanarImage.wrapRenderedImage(scaledImage);
    BufferedImage bufferedImage = planarImage.getAsBufferedImage();
    planarImage.dispose();
    return bufferedImage;
}
 

import javax.media.jai.operator.ScaleDescriptor; //导入依赖的package包/类
protected void readMasks() {
    File file;
    if (metadata != null) {
        try {
            String maskFileName = metadata.getMaskFileName();
            if (maskFileName != null) {
                file = productDirectory.getFile(maskFileName);
                if (file != null && file.exists()) {
                    GeoTiffProductReader reader = new GeoTiffProductReader(getReaderPlugIn());
                    Product udmProduct = reader.readProductNodes(file, null);
                    Band srcBand = udmProduct.getBandAt(0);
                    float scaleX = (float)metadata.getRasterWidth() / (float)udmProduct.getSceneRasterWidth();
                    float scaleY = (float)metadata.getRasterHeight() / (float)udmProduct.getSceneRasterHeight();
                    RenderedOp renderedOp = ScaleDescriptor.create(srcBand.getSourceImage(), scaleX, scaleY, 0.0f, 0.0f, Interpolation.getInstance(Interpolation.INTERP_NEAREST), null);
                    Band targetBand = product.addBand("unusable_data", srcBand.getDataType());
                    targetBand.setSourceImage(renderedOp);
                    FlagCoding cloudsFlagCoding = createFlagCoding(product);
                    targetBand.setSampleCoding(cloudsFlagCoding);

                    List<Mask> cloudsMasks = createMasksFromFlagCodding(product, cloudsFlagCoding);
                    for (Mask mask : cloudsMasks) {
                        product.getMaskGroup().add(mask);
                    }
                }
            }
        } catch (IOException e) {
            logger.warning(e.getMessage());
        }
    }
}
 

import javax.media.jai.operator.ScaleDescriptor; //导入依赖的package包/类
/**
 * Test method tests {@link WebPWriter} with image resize options.
 *
 * @throws IOException
 *            the test fails.
 */
@Test(dataProvider = "createImagesWithScaleOptions", enabled = true)
public void testImageWriterScale(final RenderedImage image, final float xScale,
      final float yScale, final String outputName) throws IOException {
   final String extension = outputName.substring(outputName.lastIndexOf(".") + 1);

   // Scale the image.
   final RenderedOp scaledImage = ScaleDescriptor.create(image, xScale, yScale, 0f, 0f,
         Interpolation.getInstance(Interpolation.INTERP_BICUBIC_2), null);

   // get writer
   final ImageWriter imgWriter = ImageIO.getImageWritersByFormatName(extension).next();
   final ImageWriteParam imgWriteParams = new WebPWriteParam(null);
   final String testName = "ScaleOptions";
   final File file = createOutputFile(testName, outputName);
   final ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(file);
   try {
      imgWriter.setOutput(imageOutputStream);
      imgWriter.write(null, new IIOImage(scaledImage, null, null), imgWriteParams);
      final int length = (int) imageOutputStream.length();
      assertTrue(length > 0);
   } finally {
      try {
         imageOutputStream.close();
      } catch (final IOException e) {
      }
   }
}
 

import javax.media.jai.operator.ScaleDescriptor; //导入依赖的package包/类
public static RenderedOp scale(final RenderedImage renderedImage, final float xFactor, final float yFactor) {
  return ScaleDescriptor.create(renderedImage, xFactor, yFactor, 0.0f, 0.0f, new InterpolationNearest(), null);
}