[Mazharul]

Hi.. …. all
When creating binary image of a gray image by dithering by Floyd –steinberg error diffusion method which is depicted in the function “processImage(BufferedImage inputImage)” an error is reported like: Exception in thread “main”java.lang.ArrayIndexOutOfBound………[/b]

Program is compiled by Jcreator..............

Or can you suggest me something different ………….method implemented by Java.......

Secondly I want to write in file row-by-row akin to image i.e file cursor will be next line after writing 1st row pixels values of image

Code:

Function: which create binary image according to dithering by Floyd –steinberg error diffusion method

public static BufferedImage processImage(BufferedImage inputImage) {

    // Create a binary image for the results of processing

    int w = inputImage.getWidth()-1;
    int h = inputImage.getHeight()-1;
    BufferedImage outputImage = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_BINARY);

    // Work on a copy of input image because it is modified by diffusion

    WritableRaster input = inputImage.copyData(null);
    WritableRaster output = outputImage.getRaster();
    final int threshold = 128;
    int value, error;

    for (int y = 0; y < h; ++y)
      for (int x = 0; x < w; ++x) {

        value = input.getSample(x, y, 0);

        // Threshold value and compute error

        if (value < threshold) {
          output.setSample(x, y, 0, 0);
          error = value;
        }
        else {
          output.setSample(x, y, 0, 1);
          error = value - 255;
        }

        // Spread error amongst neighbouring pixels

        value = input.getSample(x+1, y, 0);
        input.setSample(x+1, y, 0, clamp(value + 0.4375f * error));
        value = input.getSample(x-1, y+1, 0);
        input.setSample(x-1, y+1, 0, clamp(value + 0.1875f * error));
        value = input.getSample(x, y+1, 0);
        input.setSample(x, y+1, 0, clamp(value + 0.3125f * error));
        value = input.getSample(x+1, y+1, 0);
        input.setSample(x+1, y+1, 0, clamp(value + 0.0625f * error));

      }
   return outputImage;

  }


  // Forces a value to a 0-255 integer range

  public static int clamp(float value) {
    return Math.min(Math.max(Math.round(value), 0), 255);
  }



Main Program Code:


import java.awt.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;

public class BufferConversion {
    private JScrollPane getContent(BufferedImage image) {
    	
    	BufferedImage img=processImage(image);
    	
        int[][] data = extractData(img);
        String path = "bufferConversion.txt";
        writeToFile(data, path);
        JLabel label = new JLabel(new ImageIcon(image), JLabel.CENTER);
        return new JScrollPane(label);
    }
    
    
    public static BufferedImage processImage(BufferedImage inputImage) {

    // Create a binary image for the results of processing

    int w = inputImage.getWidth()-1;
    int h = inputImage.getHeight()-1;
    BufferedImage outputImage = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_BINARY);

    // Work on a copy of input image because it is modified by diffusion

    WritableRaster input = inputImage.copyData(null);
    WritableRaster output = outputImage.getRaster();
    final int threshold = 128;
    int value, error;

    for (int y = 0; y < h; ++y)
      for (int x = 0; x < w; ++x) {

        value = input.getSample(x, y, 0);

        // Threshold value and compute error

        if (value < threshold) {
          output.setSample(x, y, 0, 0);
          error = value;
        }
        else {
          output.setSample(x, y, 0, 1);
          error = value - 255;
        }

        // Spread error amongst neighbouring pixels

        value = input.getSample(x+1, y, 0);
        input.setSample(x+1, y, 0, clamp(value + 0.4375f * error));
        value = input.getSample(x-1, y+1, 0);
        input.setSample(x-1, y+1, 0, clamp(value + 0.1875f * error));
        value = input.getSample(x, y+1, 0);
        input.setSample(x, y+1, 0, clamp(value + 0.3125f * error));
        value = input.getSample(x+1, y+1, 0);
        input.setSample(x+1, y+1, 0, clamp(value + 0.0625f * error));

      }
   return outputImage;

  }


  // Forces a value to a 0-255 integer range

  public static int clamp(float value) {
    return Math.min(Math.max(Math.round(value), 0), 255);
  }

    
    
    
    
    

    private int[][] extractData(BufferedImage image) {
        int w = image.getWidth();
        int h = image.getHeight();
        System.out.printf("w = %d  h = %d%n", w, h);
        WritableRaster raster = image.getRaster();
        int[][] data = new int[h][w];
        for (int y = 0; y < h; y++) {
            for (int x = 0; x < w; x++) {
                data[y][x] = raster.getSample(x, y, 0);
            }
        }
        return data;
    }
private void writeToFile(int[][] data, String path) {
        int h = data.length;
        int w = data[0].length;
        int[] array = new int[h*w];
        for(int y = 0; y < h; y++) {
            for(int x = 0; x < w; x++) {
                int index = y*w + x;
                array[index] = data[y][x];
            }
        }
        try {
            File file = new File(path);
            BufferedWriter bw = new BufferedWriter(
                                new OutputStreamWriter(
                                new FileOutputStream(file)));
            
            for(int i = 0; i < array.length; i++) {
                String s = String.valueOf(array[i]) + " ";
                bw.write(s, 0, s.length());
            }
            bw.close();
        } catch(IOException e) {
            System.out.println("write error: " + e.getMessage());
        }
    }
    
   
    public static void main(String[] args) throws IOException {
        String path = "C:/shobuj.jpg";
        BufferedImage image = ImageIO.read(new File(path));
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new BufferConversion().getContent(image));
        f.setSize(500,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}