To convert the colored image to grayscale.
Get the red green blue values of each pixel
Get the average of these 3 colors.
Replace the RGB values with the average.
Create a new pixel value from the modified colors.
Set the new value to the pixel.
Example
import java.io.File;
import java.io.IOException;
import java.awt.Color;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
public class Color2Grey {
public static void main(String args[])throws IOException {
//Reading the image
File file= new File("D:\\Images\\car.jpg");
BufferedImage img = ImageIO.read(file);
for (int y = 0; y < img.getHeight(); y++) {
for (int x = 0; x < img.getWidth(); x++) {
//Retrieving the values of a pixel
int pixel = img.getRGB(x,y);
//Creating a Color object from pixel value
Color color = new Color(pixel, true);
//Retrieving the R G B values
int red = color.getRed();
int green = color.getGreen();
int blue = color.getBlue();
//Finding the average of the red green blue values
int average = (red+green+blue)/3;
//Creating new Color object
color = new Color(average, average, average);
//Setting new Color object to the image
img.setRGB(x, y, color.getRGB());
}
}
//Saving the modified image
file = new File("D:\\Images\\grey_image.jpg");
ImageIO.write(img, "jpg", file);
System.out.println("Done...");
}
}Input
Output
