javax.imageio.IIOImage#getRenderedImage ( )源码实例Demo

@Override
public void write(IIOMetadata streamMetadata, IIOImage image, ImageWriteParam param) throws IOException {
  if (param == null) {
    param = getDefaultWriteParam();
  }

  WebPWriteParam writeParam = (WebPWriteParam) param;

  ImageOutputStream output = (ImageOutputStream) getOutput();
  RenderedImage ri = image.getRenderedImage();

  byte[] encodedData = encode(writeParam.getEncoderOptions(), ri);
  output.write(encodedData);
}
 

/**
 * Convenience method that returns a scaled instance of the provided
 * {@code IIOImage}.
 *
 * @param iioSource the original image to be scaled
 * @param scale the desired scale
 * @return a scaled version of the original {@code IIOImage}
 */
public static IIOImage getScaledInstance(IIOImage iioSource, float scale) {
    if (!(iioSource.getRenderedImage() instanceof BufferedImage)) {
        throw new IllegalArgumentException("RenderedImage in IIOImage must be BufferedImage");
    }

    if (Math.abs(scale - 1.0) < 0.001) {
        return iioSource;
    }

    BufferedImage source = (BufferedImage) iioSource.getRenderedImage();
    BufferedImage target = getScaledInstance(source, (int) (scale * source.getWidth()), (int) (scale * source.getHeight()));
    return new IIOImage(target, null, null);
}
 

@Override
public void write( IIOMetadata streamMetadata, IIOImage image, ImageWriteParam param ) throws IOException {
  if ( param == null ) {
    param = getDefaultWriteParam();
  }

  WebPWriteParam writeParam = (WebPWriteParam) param;

  ImageOutputStream output = ( ImageOutputStream ) getOutput();
  RenderedImage ri = image.getRenderedImage();

  byte[] encodedData = WebP.encode(writeParam, ri);
  output.write( encodedData );
}