I’m a computer science student, I took an introductory course to data compression, and I am working on my project for the course, so the idea was to maybe use delta encoding to compress and decompress an image but I’m looking for a way to further improve it.

I thought of maybe implementing Huffman encoding after using the delta encoding but after looking up ways on how to do it it seemed robust and very complicated. I would like to have your opinion on what I can do to advance from the point I’m at now, and if Huffman was a good decision I would more than appreciate tips on how to implement it. This is my current code:
ignore the fact the main method is in the class itself, it was for test purposes.

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class Compressor {
    public static void main(String[] args) throws IOException {
        BufferedImage originalImage = ImageIO.read(new File("img.bmp"));
        BufferedImage compressedImage = compressImage(originalImage);
        ImageIO.write(compressedImage, "jpeg", new File("compressed.jpeg"));
        BufferedImage decompressedImage = decompressImage(compressedImage);
        ImageIO.write(decompressedImage, "bmp", new File("decompressed.bmp"));
    }

    public static BufferedImage compressImage(BufferedImage image) {
        int width = image.getWidth();
        int height = image.getHeight();
        BufferedImage compressedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                int rgb = image.getRGB(x, y);
                int delta = rgb;
                if (x > 0) {
                    delta = rgb - image.getRGB(x - 1, y);
                } else if (y > 0) {
                    delta = rgb - image.getRGB(x, y - 1);
                }
                compressedImage.setRGB(x, y, delta);
            }
        }
        return compressedImage;
    }

    public static BufferedImage decompressImage(BufferedImage compressedImage) {
        int width = compressedImage.getWidth();
        int height = compressedImage.getHeight();
        BufferedImage decompressedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                int delta = compressedImage.getRGB(x, y);
                int rgb;
                if (x == 0 && y == 0) {
                    rgb = delta;
                } else if (x > 0) {
                    rgb = delta + decompressedImage.getRGB(x - 1, y);
                } else if (y > 0) {
                    rgb = delta + decompressedImage.getRGB(x, y - 1);
                } else {
                    rgb = delta;
                }
                decompressedImage.setRGB(x, y, rgb);
            }
        }
        return decompressedImage;
    }
}

Thanks in advance!