使用thumbnailator 时部分图片抛异常

net.coobird.thumbnailator.tasks.UnsupportedFormatException: No suitable ImageReader found for source data.
    at net.coobird.thumbnailator.tasks.io.InputStreamImageSource.read(Unknown Source)
    at net.coobird.thumbnailator.tasks.SourceSinkThumbnailTask.read(Unknown Source)
    at net.coobird.thumbnailator.Thumbnailator.createThumbnail(Unknown Source)
    at net.coobird.thumbnailator.Thumbnails$Builder.toOutputStream(Unknown Source)

处理代码如下：

　　　　　　　　　　Blob zp = rs.getBlob("swry_zp");
                if(zp!=null){
                    is=zp.getBinaryStream();
                    if (null != is) {
                        baos = new ByteArrayOutputStream();
                        //对图片进行压缩处理
                        Thumbnails.of(is).forceSize(98, 137).toOutputStream(baos);
                        //将照片进行Base64转码
                        sy.setSwry_zp(Base64.encodeBase64String(baos.toByteArray()));
                    }
                }

从oracle中读出照片信息，照片以blog格式存储，然后以Base64编码返回给客户端，以上错误信息只是在获取某些照片信息时报错，有些照片

这种方式处理是没有问题的．当前是：

Thumbnails.of(is).forceSize(98, 137).toOutputStream(baos);
抛出IO异常，然后rs就中断了：

 while(rs.next()){}

其源码中抛出此异常的代码段如下：

public BufferedImage read() throws IOException
        {
                ImageInputStream iis = ImageIO.createImageInputStream(is);

                if (iis == null)
                {
                        throw new IOException("Could not open InputStream.");
                }

                Iterator<ImageReader> readers = ImageIO.getImageReaders(iis);
                if (!readers.hasNext())
                {
                        throw new UnsupportedFormatException(
                                        UnsupportedFormatException.UNKNOWN,
                                        "No suitable ImageReader found for source data."
                        );
                }

                ImageReader reader = readers.next();
                reader.setInput(iis);
                inputFormatName = reader.getFormatName();

                BufferedImage img = reader.read(FIRST_IMAGE_INDEX);

                iis.close();

                return img;
        }

具体原因还没有找出，