使用Java ImageIO进行Tiff压缩

Question

I am having issues converting a png to tiff. The conversion goes fine, but the image is huge. I think the issue is that I am not doing the compression correctly? Anyone have any suggestions??

Here is the code sample

public static void test() throws IOException {

    // String fileName = "4958813_1";
    String fileName = "4848970_1";
    String inFileType = ".PNG";
    String outFileType = ".TIFF";

    ImageIO.scanForPlugins();

    File fInputFile = new File("I:/HPF/UU/" + fileName + inFileType);
    InputStream fis = new BufferedInputStream(new FileInputStream(
            fInputFile));
    PNGImageReaderSpi spi = new PNGImageReaderSpi();
    ImageReader reader = spi.createReaderInstance();

    ImageInputStream iis = ImageIO.createImageInputStream(fis);
    reader.setInput(iis, true);
    BufferedImage bi = reader.read(0);

    TIFFImageWriterSpi tiffspi = new TIFFImageWriterSpi();
    ImageWriter writer = tiffspi.createWriterInstance();
    //Iterator<ImageWriter> iter =  ImageIO.getImageWritersByFormatName("TIFF");
    //ImageWriter writer = iter.next();

    ImageWriteParam param = writer.getDefaultWriteParam();
    param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);

    param.setCompressionType("LZW");
    param.setCompressionQuality(0.5f);
    File fOutputFile = new File("I:\\HPF\\UU\\" + fileName + outFileType);
    ImageOutputStream ios = ImageIO.createImageOutputStream(fOutputFile);
    writer.setOutput(ios);
    writer.write(bi);

}

Answer 1

Writer.getDefaultWriteParam() only creates an ImageWriteParam object, it doesn't link it back to anything else.

I don't see any mechanism in your code for your modified param object to be subsequently used in the ImageWriter .

I believe that instead of:

writer.write(bi);

you need to use:

writer.write(null, new IIOImage(bi, null, null), param);

Answer 2

I don't know Java IO, but generally you want to look at a few things

1. Can you use JPEG compression instead of LZW?
2. See how to set the TIFF strip size -- if small size is what you want, set it to the height of the image.

Edit: Looks like a TiffWriteParam has the following methods

tiffWriteParam.setTilingMode(ImageWriteParam.MODE_EXPLICIT);
tiffWriteParam.setTiling(imageWidth, imageHeight, 0, 0);

set the imageWidth and imageHeight vars to your image's size. The downside is that it will be slower to read out regions of the image.