java - 使用 ImageIO 编写带有图层(即分解级别)的 JPEG 2000

Question

好的，这是我们的问题:

我们正在尝试使用 imageio 将一系列黑白 .tiff 文件转换为 jpeg2000 .jpf 文件。我们总是获得可查看的 .jpf 文件，但它们通常没有指定的层数或缩放级别。

这是我们的代码:

 //Get the tiff reader
 Iterator<ImageReader> readerIterator = ImageIO.getImageReadersByFormatName("tiff");
 ImageReader tiffreader = readerIterator.next();

 //make an ImageInputStream from our tiff file and have the tiff reader read it
 ImageInputStream iis = ImageIO.createImageInputStream(itemFile);

 tiffreader.setInput(iis);

 //just pass empty params to the tiff reader
 ImageReadParam tparam;
 tparam = new TIFFImageReadParam();

 IIOImage img = tiffreader.readAll(0, tparam);


 //set up target file
 File f = new File(itemTargetDirectory.getAbsolutePath() + "/" + destFileName);

 //we have tried FILTER_97 as well as different ProgressionTypes and compression settings
 J2KImageWriteParam param;
 param = new J2KImageWriteParam();
 param.setProgressionType("layer");
 param.setFilter(J2KImageWriteParam.FILTER_53);
 //Our problem is that this param is not always respected in the resulting .jpf
 param.setNumDecompositionLevels(5);

 //get the JPEG 2000 writer                             
 Iterator<ImageWriter> writerIterator = ImageIO.getImageWritersByFormatName("JPEG 2000");
 J2KImageWriter jp2kwriter = null;
 jp2kwriter = (J2KImageWriter) writerIterator.next();

 //write the jpf file
 ImageOutputStream ios = ImageIO.createImageOutputStream(f);
 jp2kwriter.setOutput(ios);
 jp2kwriter.write(null, img, param);

这是一种奇怪的体验，因为相同的代码在后续运行中表现不同。任何见解将不胜感激!

Answer 1

是否所有 TIFF 文件都具有相同的设置(颜色模型)？ J2KImageWriter.java显示当索引颜色或多像素打包源图像用作输入时分解级别设置(强制)为零。