Java - image output

[NotAGolf]

I've got a 2D array of pixels that I want to output to screen. What's the best/easiest way to go about this?

At the minute I'm just using a buffered image which I've loaded in and just outputting the whole lot to screen and using JFrames and JPanels etc. Then I was using .setRGB to draw over the top but I've kind of reached the limit of what I can do with that.

Anyone know of any good tutorials that can walk me through how to do this?

Thanks.

 

[RobH]

Can you post your existing code?

 

[NotAGolf]

Here you go RobH. It loads the image, creates an array of 2D pixels using .getRGB(), then outputs the image using various Swing components. Finally it draw a small line on the image using .setRGB to overwrite those particular pixels.

//Store the two input images as buffered images
    public void loadImages() throws FileNotFoundException, IOException{ 
        barcodeImage = getImage("8DigitsGrey.jpg");
    }
    
    
    //Read the images in
    public BufferedImage getImage(String filename) throws FileNotFoundException, IOException {
        
        File file = new File(filename);
        if(!file.exists())
            throw new FileNotFoundException(filename);
        
        barcodeImage = ImageIO.read(file);
        
        return barcodeImage;
    }
    
    
    //Create a 2Darray of pixels of the image
    public void buildArray() {
        
        int width = barcodeImage.getWidth();
        int height = barcodeImage.getHeight();
        pixelData = new int[width][height];
              
        for(int i=0; i<width; i++) {
            for(int j=0; j<height; j++) { 
                pixelData[i][j] = (barcodeImage.getRGB(i,j))&255; //getRGB returns the RGB value of the current pixel                   
            }         
        }
    }





    private static void  createAndShowGUI() throws FileNotFoundException, IOException {    
        
        JFrame frame = new JFrame("Image"); // Create the container        
        
        //Quit the application when this frame is closed
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
  
        // Create and add the content
        Barcode panel = new Barcode();
        frame.add(panel);
        
        // Display the window
        frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
        frame.setLocation(FRAME_X_ORIGIN, FRAME_Y_ORIGIN);
        frame.setVisible(true); // Now the frame will appear on screen      
    }  
    
    
public Barcode() throws FileNotFoundException, IOException {
        
        loadImages();
        buildArray();
             
        JPanel imagePanel = new JPanel();
        imagePanel.setLayout(new BorderLayout());  
        picLabel = new JLabel(new ImageIcon(getImage("8Digits.jpg")));
        imagePanel.add("Center", picLabel);     
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(FRAME_WIDTH, FRAME_HEIGHT));
        add("Center", imagePanel);

        drawSquare();    
    }


//Draws a line onto the image
    public void drawSquare(){
        
        barcodeImage.setRGB( 319, barcodeT, RED);
        barcodeImage.setRGB( 320, barcodeT, RED);
        barcodeImage.setRGB( 321, barcodeT, RED);
}
    
    
    
    public static void main(String[] args) throws FileNotFoundException, IOException {
        
                createAndShowGUI();
        
    }

Thanks.

 

[RobH]

Ok, I understand the code and see what it's doing but what are you trying to do and why is this code limiting you?

 

[NotAGolf]

Ok, I understand the code and see what it's doing but what are you trying to do and why is this code limiting you?

I'll give you a quick overview of the project: We are given an image and are required to extract the ROI (Region of Interest) from the image. The image in question is a barcode (complete with background label) and the ROI is the number below it.

Now with my code I basically search the entire image's pixel data and cut out the background label that i'm not interested, then I want to cut out the bars leaving just the numbers, then seperate each number individually. Each time I seperate it (i.e. cut something out) I put the new area I am working with into a new array, so when I search it next I have less to search for. So this will leave me with 3 or 4 arrays of various sizes containing different areas.

It would just be a whole lot easier to display these arrays individually so I can check that i'm cutting out the right parts etc. I realise this is by far from the best way to go about it but its the easiest way to test it and make a working program. After I get that I can worry about making an efficient pretty program!

Cheers.

 

[SoapSurgeon]

i dont know if this will be of any use...

I think this can be done in c# using the Bitmap class, it has a method (can't remember the name) that allows you to specify a region that you are interested in, as a rectangle, and another bitmap that it will draw it to.

I know its not Java but it might be worth looking for a similar 'Bitmap' class that allows resizing/cropping rather than worrying about drawing the image pixel by pixel?