Error in converting colour image to gray scale

[LankanSniper]

I wrote bellow code is used to convert a color image to gray scale. There is an error in it.Can somebody help me with the code to fix it. Please note that i do not need to use any JAVA API to convert the color image to grey scale.

public  BufferedImage grayScale(BufferedImage img){
        Color clr;
        int r, g, b;
        float grey;
        
          for (int ix = 0; ix<img.getWidth();ix++){
            for(int iy = 0;iy<img.getHeight();iy++){ 
                 clr = Color.decode(Integer.toString(img.getRGB(ix, iy)));
                 r = clr.getRed();
                 b = clr.getBlue();
                 g = clr.getGreen();
                 grey = (float) (0.299 * r + 0.587 * g + 0.144 * b + 0.5);
                 clr = new Color(grey, grey, grey);
                 img.setRGB(ix, iy,clr.getRGB());
                
                
               // 0.299*r + 0.587*g + 0.144*b + 0.5
                
            }
          } 
        
        grayScale = img;    
        
        return img;
         
         
         
    }

Bellow method is used to save the image to save the converted image to desktop. Please help me with the code? Thank you in advaned

ProcessingImages fr = new ProcessingImages();
                
try{
                    javax.imageio.ImageIO.write(fr.grayScale(ProcessingImages.tmpSideA), "png", new File("C:\\Users\\Chathura Ekanayake\\Desktop\\GrayScale.PNG"));                                
}
 catch(Exception e){
e.printStackTrace();
}

[Tolls]

"There is an error in it."
?

Is this a game of "guess the error"?

[LankanSniper]

Yaa may b.. it dsnt work with me either.. i wanna fix it can u help me....

[Tolls]

This is a bit like going to a mechanic with your car and saying "it doesn't work"...I am not spending my time looking at the engine only for you to tell me you meant the car stereo.

So, in case I was being too subtle, what does "(t)here is an error in it" mean?

[LankanSniper]

ok.... i got what u said.... hmmmm well juz forget about what i wrote here.... Mt task is to convert color image to gray scale image..... I know bellow code will do what i required.. Bt i cant use APIs to do this....

public static void grayScale(BufferedImage colorImage){
        BufferedImage image = new BufferedImage(colorImage.getWidth(), colorImage.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
        Graphics g = image.getGraphics();
        g.drawImage(colorImage, 0, 0, null);
        g.dispose();
        grayScale = image;
 }

So i want to do it using other way round....

[Tolls]

OK. Well, hopefully someone'll come along here who knows the nuts and bolts of images.
Me? I use the API, because that's what it's there for.

Is this an exercise then?

[LankanSniper]

This is for final year project.... They give high marks as far as we stick away from APIs..

[Tolls]

Thought it had to be something like that.
I don't know the mechanics of converting from a colour to grey.
I would have said what you had above, essentially converting each pixel, was the answer...but from what you've said, that doesn't work for some reason?

[LankanSniper]

hmmmm....... :( :( :( bt i m nt sure someone will help me herE......

[Tolls]

What exactly is the problem with your original code then?