6 messages in net.java.dev.jai-imageio.interestRe: [JAI-IMAGEIO] JPEG Lossless 8/12 bit| From | Sent On | Attachments |
|---|---|---|
| jai-...@javadesktop.org | Jun 26, 2007 6:13 am | |
| Brian Burkhalter | Jun 26, 2007 8:33 am | |
| jai-...@javadesktop.org | Jun 26, 2007 8:55 am | |
| Brian Burkhalter | Jun 26, 2007 8:56 am | |
| jai-...@javadesktop.org | Jun 26, 2007 9:13 am | |
| Brian Burkhalter | Jun 26, 2007 10:13 am |
| Subject: | Re: [JAI-IMAGEIO] JPEG Lossless 8/12 bit | |
|---|---|---|
| From: | Brian Burkhalter (Bria...@Sun.COM) | |
| Date: | Jun 26, 2007 8:56:38 am | |
| List: | net.java.dev.jai-imageio.interest | |
Yes I'm using the Image I/O tools. As I understood it, the JPEG-LS (ISO-14495-1/ITU-T.87) algorithm was different to the JPEG-LOSSLESS (ISO-10918-1/ITU-T.81) algorithm?
Yes.
For this application I need to use the LOSSLESS and not the LS algorithm.
Too bad. I think the compression ratio is generally not as good for that.
my current code looks like:
ImageWriteParam iw_param = writer.getDefaultWriteParam(); iw_param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); iw_param.setCompressionType("JPEG-LOSSLESS"); iw_param.setCompressionQuality(1.0f);
I don't believe the quality setting is useful here. That value maps to the contents of the Huffman and Quantization tables.
The image io page states that 2-16bit lossless jpegs can be created using JPEG-LOSSLESS, is this just based upon the bit depth of the colormodel?
Yes. To be specific the code is this
int bitDepth = renderedImage.getColorModel().getComponentSize(0);
where 'renderedImage' is the one you are trying to write.
Based upon my test image (8bit depth in the colormodel) and the above code, I get an 8 bit lossless jpeg.
Correct.
---------------- Brian Burkhalter Java Media, Imaging, and Graphics Sun Microsystems, Inc.
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