Android DNG writeImage不支持的图像格式256

Question

大家。我尝试将图像保存为.dng扩展名。

我从ImageReader.OnImageAvailableListener中的ImageReader获取Image对象 比起我使用DngCreator类进行保存。

这是我的DngUtil类：

public class DngUtil {

private final DngCreator dngCreator;
private final Image image;

public DngUtil(DngCreator dngCreator, Image image) {
    this.dngCreator = dngCreator;
    this.image = image;
}

/**
 * Writes the dng file to the supplied output.
 */
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public void writeImage(OutputStream dngOutput) throws IOException {
    try {
        dngCreator.writeImage(dngOutput, image);
    } catch (AssertionError | IllegalStateException | IllegalArgumentException e) {
        e.printStackTrace();
        throw new IOException();
    }
}

/**
 * Closes the image. Must be called to free up resources when no longer needed. After calling
 * this method, this object should not be used.
 */
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public void close() {
    image.close();
    dngCreator.close();
}}

此字符串引发IllegalArgumentException：不支持的图像格式256

dngCreator.writeImage(dngOutput, image);

怎么了？