Re: grayscale to a JPanel does not work

From:

Knute Johnson <nospam@knutejohnson.com>

Newsgroups:

comp.lang.java.gui

Date:

Wed, 09 Feb 2011 08:37:46 -0800

Message-ID:

<upz4p.69615$gx6.36925@newsfe22.iad>

On 02/09/2011 07:29 AM, SamuelXiao wrote:

On Feb 9, 10:50 pm, "John B. Matthews"<nos...@nospam.invalid> wrote:

In article
<e11dadc9-4a6a-4b16-9845-c99c223cd...@h19g2000prh.googlegroups.com>,

SamuelXiao<foolsmart2...@gmail.com> wrote:

[...]
I currently paint line chart/bar chart to there (the drawing area
painting line chart/bar chart).
[...]
In addition, I have tried the example in

<http://groups.google.com/group/comp.lang.java.programmer/msg/d4c436ab...>

but it does not work as well.

This is the very code I was going to suggest; it works correctly for
me. Are you having trouble converting your chart to a BufferedImage?
I don't know how you create your chart, but org.jfree.chart.JFreeChart
includes suitable methods.

Any help would be highly appreciated.

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>

Hi, the code converts an imaged to grayscale. but for my situation, I
need to converts Graphics in an applet (lines, rectangels, string) to
grayScale. The paint method in my Applet is like:

public void paint(Graphics g){
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;

g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

//colorSchemeList.getSelectedIndex
   switch(colorSchemeList.getSelectedIndex()){
    case 0:
     showGrayScale(g2d);
        break;
    case 1:
        showHighContrast(g2d);
        break;
    }
}

But it does not work as the example. It just paint another rectangle
with gray color on top of those line/string/so on. Do you have any
idea for it? Thanks.

    public static BufferedImage convertToGray(BufferedImage image) {
         BufferedImage gray = new BufferedImage(image.getWidth(),
          image.getHeight(),BufferedImage.TYPE_BYTE_GRAY);
         ColorConvertOp op = new ColorConvertOp(
          image.getColorModel().getColorSpace(),
          gray.getColorModel().getColorSpace(),null);
         op.filter(image,gray);
         return gray;
     }
--

Knute Johnson
s/nospam/knute2011/