Converting RGB to CIE Luv using ColorSpace

I've been reading the documentation of all the classes in java.awt.color, trying to figure out if the JDK has the ability to convert an RGB value into a CIE Luv value. It seems to have Luv related constants, but no obvious way to make the conversion.
If anyone knows how to use the ColorSpace to convert between different color spaces, lease let me know how!
Mark McKay
http://www.kitfox.com

Thanks for the detailed reply. Sure clear some of the doubts.
I just start to draw/design in Photoshop and illustrator, I save my files most as PNG, for a transparent background.
After I went to officework do the poster printing, I found the color of my print image are not as vivid as Mac preview.
To be precise, the poster I printed looks like has a very thin grey layer, it is not much noticeable, but it indeed lost some vivid color. As I want to print out my works and keep color as close exact as Mac preview, here is the issue of coverting RGB CMYK.
Please feel free to add for below:
1, Should I set color space in CMYK before drawing in PS/AI
2, in PS, I convert profile from PNG file to CMYK save as psd file, that psd file preview exactly same as PNG.
But when saved as PDF, the file preview a bit grey. Can someone explain this?
3, Now im thinking, since CMYK is all about printers, it really should be the profession in printing shop who shall check my image, and edit/convert to the right color space to fit their printers.

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source code
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.stream.ImageOutputStream;
import org.w3c.dom.Node;
import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class TestImage {
     public static void main(String args[]) throws ImageFormatException, IOException{
          BufferedImage readImage = null;
          try {
              readImage = ImageIO.read(new File("C:\\TEST.jpg"));
          } catch (Exception e) {
              e.printStackTrace();
              readImage = null;
          readImage = CMYKProfile.getInstance().doChColor(readImage);
          writeImage(readImage, "C:\\TEST_after_.jpg", 1.0f);
    protected static String getSuffix(String filename) {
        int i = filename.lastIndexOf('.');
        if(i>0 && i<filename.length()-1) {
            return filename.substring(i+1).toLowerCase();
        return "";
    protected static void writeImage(BufferedImage image, String filename, float quality) {
        Iterator writers = ImageIO.getImageWritersBySuffix(getSuffix(filename));
        System.out.println("filename�F"+filename);
        if (writers.hasNext()) {
            ImageWriter writer = (ImageWriter)writers.next();
            try {
                ImageOutputStream stream
                    = ImageIO.createImageOutputStream(new File(filename));
                writer.setOutput(stream);
                ImageWriteParam param = writer.getDefaultWriteParam();
                if (param.canWriteCompressed()) {
                    param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);//NO COMPRESS
                    param.setCompressionQuality(quality);
                } else {
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                IIOMetadata metadata = null;
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                        metadata.setFromTree(sFormat, node);
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                writer.dispose();
                return;
            } catch (IOException ex) {
                ex.printStackTrace();
}

Hi,
I am having similar problems. I have read somewhere that png format can not handle CMYK colorspace anyway, which I find odd (and plainly stupid IM(NS)HO) which would mean that converting to RGB and therefore using profiles is mandatory.
May be you should check if the internal format of the png files claims it is RGB or CMYK (using ImageMagick's "identify" command for example).
HTH
JG

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(1)
http://en.wikipedia.org/wiki/Rec._709
(2)
http://en.wikipedia.org/wiki/Rec._601
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With numbers not preserved: no change of the appearance, as expected.
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Hi Jon
Sorry its been so long!!
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Hi guy
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We need to know some more information.
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I have few BASIC Questions on converting RGB to CMYK in Photoshop and Illustrator. Hope could get some professional insights here.
1, Are all the DTG printers set only in CMYK color mode ?
2, If there is no difference after viewing RGB image with 'Gamaut Warning' (Photoshop), Does that mean I'll have the exact print result as monitor view ?
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3, Please list some the most effective way to convert RGB to CMYK, and keep the final CMYK color result as close as the RGB.
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Thanks for the detailed reply. Sure clear some of the doubts.
I just start to draw/design in Photoshop and illustrator, I save my files most as PNG, for a transparent background.
After I went to officework do the poster printing, I found the color of my print image are not as vivid as Mac preview.
To be precise, the poster I printed looks like has a very thin grey layer, it is not much noticeable, but it indeed lost some vivid color. As I want to print out my works and keep color as close exact as Mac preview, here is the issue of coverting RGB CMYK.
Please feel free to add for below:
1, Should I set color space in CMYK before drawing in PS/AI
2, in PS, I convert profile from PNG file to CMYK save as psd file, that psd file preview exactly same as PNG.
But when saved as PDF, the file preview a bit grey. Can someone explain this?
3, Now im thinking, since CMYK is all about printers, it really should be the profession in printing shop who shall check my image, and edit/convert to the right color space to fit their printers.

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Hi Morgan,
I think you have at least two choices:
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ps - To display tags in a post, use &lt; for < and &gt; for >

Converting RGB to CIE Luv using ColorSpace

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