Converting image to Grayscale without using any methods Java OpenCV.

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