Сравнение двух картинок по пикселям

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
 
 
public class CompareTwoImages {
    private static BufferedImage image1, image2, imageResult;
    private static boolean isIdentic;
    // a number of pieces along vertical and horizontal
    private static int compareX, compareY;
    
    // “tolerance” comparison parameter that allows to treat similar colors as the same
    private static double sensitivity = 0.10;
    
    public CompareTwoImages(String file1, String file2) throws IOException {
        image1 = loadPNG(file1);
        image2 = loadPNG(file2);
    }
    
    // set a number of pieces along vertical and horizontal
    public void setParameters(int compareX, int compareY) {
        CompareTwoImages.compareX = compareX;
        CompareTwoImages.compareY = compareY;
    }
    
    // compare the two images in this object.
    public void compare() {
        // setup change display image
        imageResult = new BufferedImage(image2.getWidth(null), image2.getHeight(null), BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = imageResult.createGraphics();
        g2.drawImage(image2, null, null);
        g2.setColor(Color.RED);
        // assign size of each section
        int blocksX = (int)(image1.getWidth()/compareX);
        int blocksY = (int)(image1.getHeight()/compareY);
        CompareTwoImages.isIdentic = true;
        for (int y = 0; y < compareY; y++) {
            for (int x = 0; x < compareX; x++) {
                int result1 [][] = convertTo2D(image1.getSubimage(x*blocksX, y*blocksY, blocksX - 1, blocksY - 1));
                int result2 [][] = convertTo2D(image2.getSubimage(x*blocksX, y*blocksY, blocksX - 1, blocksY - 1));
                for (int i = 0; i < result1.length; i++) {
                    for (int j = 0; j < result1[0].length; j++) {
                        int diff = Math.abs(result1[i][j] - result2[i][j]);
                        if (diff/Math.abs(result1[i][j]) > sensitivity) {
                            // draw an indicator on the change image to show where change was detected.
                            g2.drawRect(x*blocksX, y*blocksY, blocksX - 1, blocksY - 1);
                            isIdentic = false;
                        }
                    }
                }
            }
        }
    }
    
    public BufferedImage getImageResult() {
        return imageResult;
    }
    
    // representation fragment's of the picture in a two-dimensional integer array
    public int[][] convertTo2D(BufferedImage subimage) {
        int width = subimage.getWidth();
        int height = subimage.getHeight();
        int[][] result = new int[height][width];
        
        for (int row = 0; row < height; row++) {
            for (int col = 0; col < width; col++) {
                result[row][col] = subimage.getRGB(col, row);
            }
        }
        return result;
    }
 
    // reading picture from disk
    public static BufferedImage loadPNG(String filename) throws IOException {
        BufferedImage img = null;
        try {
            img = ImageIO.read(new File(filename));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return img;
        
    }
    
    // writing picture into disk
    public static void savePNG(BufferedImage bimg, String filename) {
        try {
            File outputfile = new File(filename);
            ImageIO.write(bimg, "png", outputfile);
        } catch(IOException e) {
            e.printStackTrace();
        }
    }
 
    public boolean isIdentic() {
        return isIdentic;
    }
 
    
}

import java.io.IOException;
 
 
public class CompareTwoImagesTest {
    public static void main(String[] args) throws IOException {
        
        CompareTwoImages cti = new CompareTwoImages("/Users/.../img/img1.png",
 "/Users/.../img/img2.png");
        cti.setParameters(10, 10);
        cti.compare();
        if (!cti.isIdentic()) {
            System.out.println("no match");
            CompareTwoImages.savePNG(cti.getImageResult(), "/Users/.../img/result.png");
        } else {
            System.out.println("match");
        }
    }
}

    public void compare() {
 
        if (image1.getWidth() != image2.getWidth() || image2.getHeight() != image1.getHeight()) {
            System.out.println("dimensions must be the same");
            return;
        }
        imageResult = new BufferedImage(image2.getWidth(null), image2.getHeight(null), BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = imageResult.createGraphics();
 
        isIdentic = true;
        for (int i = 0; i < image1.getWidth(); i++) {
            for (int j = 0; j < image1.getHeight(); j++) {
                int rgb = Math.abs(image1.getRGB(i, j) - image2.getRGB(i, j));
                if (rgb != 0) {
                    g2.setColor(new Color(rgb));
                    g2.drawRect(i, j, 1, 1);
                    isIdentic = false;
                }
            }
        }
    }