covert Image To Gray - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Color

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Description

covert Image To Gray

Demo Code


//package com.java2s;

import java.awt.*;
import java.awt.image.BufferedImage;

public class Main {
    public static BufferedImage covertImageToGray(BufferedImage original) {

        int alpha, red, green, blue;
        int newPixel;

        BufferedImage lum = new BufferedImage(original.getWidth(),
                original.getHeight(), original.getType());

        for (int i = 0; i < original.getWidth(); i++) {
            for (int j = 0; j < original.getHeight(); j++) {
                // Get pixels by R, G, B
                alpha = new Color(original.getRGB(i, j)).getAlpha();
                red = new Color(original.getRGB(i, j)).getRed();
                green = new Color(original.getRGB(i, j)).getGreen();
                blue = new Color(original.getRGB(i, j)).getBlue();

                red = (int) (0.299 * red + 0.587 * green + 0.114 * blue);
                // Return back to original format
                newPixel = colorToRGB(alpha, red, red, red);
                // Write pixels into image
                lum.setRGB(i, j, newPixel);
            }//from   ww  w. ja v  a2 s.  c  om
        }

        return lum;
    }

    private static int colorToRGB(int alpha, int red, int green, int blue) {

        int newPixel = 0;
        newPixel += alpha;
        newPixel = newPixel << 8;
        newPixel += red;
        newPixel = newPixel << 8;
        newPixel += green;
        newPixel = newPixel << 8;
        newPixel += blue;

        return newPixel;
    }
}

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