CODEWITHSUNDEEP
javaimage-processing
Rohit S
Rohit S

Reputation: 395

Error in writing the grayscale image

Figure 1 Figure 2

Following is the code I have written to change the pixel values of a gray scale image to create a full white image (all pixel values set to 255). But instead of getting a complete white image I'm getting the black vertical bars in between as shown in the figure 2. Where have I gone wrong?

package dct;

import java.awt.image.BufferedImage;
import java.awt.image.WritableRaster;
import java.io.File;
import javax.imageio.ImageIO;

public class writeGScale {
    public static void main(String[] args){
        File file = new File("bridge.jpg");
        BufferedImage img = null;
        try{
            img = ImageIO.read(file);
        }
        catch(Exception e){
            e.printStackTrace();
        }

        int width = img.getWidth();
        int height = img.getHeight();
        int[] tempArr = new int[width*height];

        WritableRaster raster1=img.getRaster();

        for(int i=0;i<width;i++){
            for(int j=0;j<height;j++){
                tempArr[0] = 255;
                raster1.setPixel(i, j, tempArr);
            }
        }

        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY);
        image.setData(raster1);

        try{
            File ouptut = new File("change.png");
            ImageIO.write(image, "png", ouptut);
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }
}

Upvotes: 4

Views: 122

Answers (1)

Madhawa Priyashantha
Madhawa Priyashantha

Reputation: 9872

i don't know why you pass big array tempArr = new int[width*height] to setpixel method .i created a int col array which represent white color and i passed it to setPixel() method then i able to get complete white image as output. 

int col[]={255,255,255};

WritableRaster raster1=img.getRaster();

for(int i=0;i<width;i++)
{
    for(int j=0;j<height;j++)
    {
        raster1.setPixel(i, j, col);
    }
}

Upvotes: 2

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