apache POI XWPF 文档中的图像有颜色失真

Images in apache POI XWPF document have color distortion

我正在尝试设计一个报告模板,其中有许多(数百个)图像被超链接引用。我希望文档小于 25Mb(用于电子邮件和其他原因),因此我尝试使用以下代码压缩图像:

//I get the input stream
InputStream ins = entity.images.getInputStream(img);
BufferedImage bufImg = ImageIO.read(ins);

//I compress the image
ByteArrayOutputStream compressed = new ByteArrayOutputStream();
ImageOutputStream outputStream = ImageIO.createImageOutputStream(compressed);
ImageWriter jpgWriter = ImageIO.getImageWritersByFormatName("jpg").next();
ImageWriteParam jpgWriteParam = jpgWriter.getDefaultWriteParam();
jpgWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
jpgWriteParam.setCompressionQuality(0.98f);
jpgWriter.setOutput(outputStream);
jpgWriter.write(null, new IIOImage(bufImg, null, null), jpgWriteParam);
jpgWriter.dispose();
byte[] jpegData = compressed.toByteArray();

//I attempt to add the compressed image
imgRun.addPicture(new ByteArrayInputStream(jpegData), Document.PICTURE_TYPE_JPEG,"text", Units.toEMU(newWidth), Units.toEMU(newHeight));

图像写入文档,但颜色失真。在我的例子中,它们都是 red/orange 颜色。关于导致 this/what 的原因有什么想法吗?

问题似乎是某些图像是 .gif 文件。

无论如何,我解决了这个问题,方法是先将所有图像简单地转换为 .jpg,然后再进行压缩。见下文:

BufferedImage newBufferedImage = new BufferedImage(bufImg.getWidth(),
          bufImg.getHeight(), BufferedImage.TYPE_INT_RGB);
newBufferedImage.createGraphics().drawImage(bufImg, 0, 0, Color.WHITE, null);