给出java代码使用dcm4che库，完成从dicom协议文件中获取图片

以下是使用dcm4che库获取Dicom图像的Java代码示例：

import org.dcm4che3.data.Attributes;
import org.dcm4che3.data.Tag;
import org.dcm4che3.imageio.plugins.dcm.DicomImageReadParam;
import org.dcm4che3.imageio.plugins.dcm.DicomImageReader;

import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;

public class DicomImageReaderExample {

    public static void main(String[] args) throws IOException {
        // 读取Dicom文件
        File dicomFile = new File("path/to/dicom/file.dcm");
        ImageInputStream iis = ImageIO.createImageInputStream(dicomFile);

        // 获取Dicom图像
        Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName("DICOM");
        ImageReader reader = readers.next();
        reader.setInput(iis);

        // 设置读取参数
        DicomImageReadParam param = new DicomImageReadParam();
        param.setWindowCenter(getWindowCenter(reader.getImageMetadata(0)));
        param.setWindowWidth(getWindowWidth(reader.getImageMetadata(0)));

        // 读取图像
        int imageIndex = 0; // 读取第一张图像
        ImageReadParam irp = reader.getDefaultReadParam();
        irp.setDestinationType(reader.getRawImageType(imageIndex));
        irp.setSourceRegion(reader.getImageMetadata(imageIndex).getAsTree(null).getChild(0).getAttribute(Tag.PixelData).getByteValues().length);
        irp.setSourceBands(new int[] {0});
        irp.setSourceSubsampling(1, 1, 0, 0);
        irp.setSourceRegion(reader.getImageMetadata(imageIndex).getAsTree(null).getChild(0).getAttribute(Tag.PixelData).getByteValues().length);
        irp.setSourceSubsampling(1, 1, 0, 0);
        irp.setSourceRegion(reader.getImageMetadata(imageIndex).getAsTree(null).getChild(0).getAttribute(Tag.PixelData).getByteValues().length);
        irp.setSourceSubsampling(1, 1, 0, 0);

        // 保存图像
        File outputFile = new File("path/to/output/file.png");
        ImageIO.write(reader.read(imageIndex, param), "png", outputFile);

        // 关闭流
        iis.close();
    }

    private static double getWindowWidth(Attributes attributes) {
        return attributes.getDouble(Tag.WindowWidth, -1.0);
    }

    private static double getWindowCenter(Attributes attributes) {
        return attributes.getDouble(Tag.WindowCenter, -1.0);
    }
}

这个示例演示了如何使用dcm4che库从Dicom文件中获取图像，并将其保存为PNG格式的文件。首先，使用ImageIO.createImageInputStream()方法读取Dicom文件。然后，使用ImageIO.getImageReadersByFormatName()方法获取Dicom图像读取器，设置读取参数，读取图像并保存图像。最后，关闭流。