Image overlay and comparison code error.

Jul 1, 2021
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I am still very much a beginner in programming, and i am facing an issue with a code that i am hoping someone could help me with. I found the java code below for overlaying and comparing the pixels of two images in an online forum. When i try to compile the code i get a syntax error. Hope you can help me find the error. I added threee images showing the errors that i am getting. Thanks in advance.

package stackexchange;

import java.awt.Color;
import java.awt.image.BufferedImage;

import javax.imageio.ImageIO;

public class PictureOverlayTest {
     * Four variables, three for the wanted BufferedImages, one String for the
     * Path of the third Image, which does not already exist.

    private BufferedImage image1;
    private BufferedImage image2;
    private BufferedImage image3;

    private String pathImage3;

    public PictureOverlayTest(String filePathAndName1, String filePathAndName2,
            String filePathAndName3) throws IOException {
         * Constructor in order to keep this method reusable and clean. Needs
         * three Strings. The paths and Filenames of all three images. Image 1
         * and 2 should exist already, Image 3 will be created if all
         * requirements are met. Constructor creates the first two buffered
         * images, sets all needed variables and starts the checkAndCompare()
         * method

        File file = new File(filePathAndName1);
        this.image1 =;

        file = new File(filePathAndName2);
        this.image2 =;

        this.pathImage3 = filePathAndName3;

    private void checkAndCompare() throws IOException {
         * This function creates the Color blue, compares the sizes of both
         * pictures and if they are the same, creates a third image. Then it
         * loops through the two images and compares each pixel. If the pixels
         * are the same, the third image gets a blue pixel at that point

        Color blue =;

        if (image1.getHeight() == image2.getHeight()
                && image1.getWidth() == image2.getWidth()) {

            image3 = new BufferedImage(image1.getWidth(), image1.getHeight(),
            for (int y = 0; y < image1.getHeight(); y++) {
                for (int x = 0; x < image1.getWidth(); x++) {

                    int colorImage1 = image1.getRGB(x, y);
                    int colorImage2 = image2.getRGB(x, y);

                    if (colorImage1 == colorImage2) {

                        image3.setRGB(x, y, blue.getRGB());

                    } else {

                        // Whatever Color you want. By default it is black.


            System.out.println("Message: Image comparison is done");

        } else {

            System.out.println("Error: Image dimensions do not match");



    private void savePicture3() throws IOException {
         * This method saves the created Image into a file onto your computer.
         * The if() statement is used to check if the file was successfully
         * created, in order to avoid unwanted errors. Keep in mind, that you
         * have to change the "bmp" in ImageIO.write() to whatever format you
         * actually want

        File file = new File(pathImage3);
        if (file.createNewFile()) {
            ImageIO.write(image3, "bmp", file);


package stackexchange;


public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        try {
            PictureOverlayTest test = new PictureOverlayTest(
        } catch (IOException e) {
            // TODO Auto-generated catch block

Screenshot 2021-07-01 131255.png
Screenshot 2021-07-01 131319.png
Screenshot 2021-07-01 131326.png
Mar 3, 2021
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Java likes to have each class in its own file, named after itself. You've got two classes, PictureOverlayTest and Main. Split those two out into and and see how if it works.

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