Upscale Resource packs

Scratch.java

import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Arrays;
import java.util.concurrent.atomic.AtomicInteger;
import javax.imageio.ImageIO;

class Scratch {

    public static void main(String[] args) throws IOException {
        Arrays.stream(new String[]{"Dyescape", "BeforeDawn"}).parallel().forEach(name -> {
            Arrays.stream(new double[]{1.0f, 1.1f, 1.2f, 1.3f, 1.4f, 1.5f, 1.6f, 1.7f}).parallel().forEach(factor -> {
                try {
                    new Scratch(name, (float) factor);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            });
        });
    }

    public Scratch(String name, float factor) throws IOException {
        Path input = Path.of("C:\\Users\\Martin\\AppData\\Roaming\\.minecraft\\resourcepacks\\" + name);
        Path output = Path.of("C:\\Users\\Martin\\AppData\\Roaming\\.minecraft\\resourcepacks\\" + name + "-Bright-" + factor);

        if (!Files.isDirectory(output)) {
            Files.walkFileTree(input, new SimpleFileVisitor<Path>() {
                @Override
                public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException {
                    Files.createDirectories(output.resolve(input.relativize(dir)));
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult visitFile(final Path file,
                                                 final BasicFileAttributes attrs) throws IOException {
                    Files.copy(file, output.resolve(input.relativize(file)));
                    return FileVisitResult.CONTINUE;
                }
            });
        }

        Path inputFolder = input.resolve("assets\\minecraft\\textures\\block");
        Path outputFolder = output.resolve("assets\\minecraft\\textures\\block");

        AtomicInteger i = new AtomicInteger();
        Files.list(inputFolder).parallel().forEach(path -> {
            try {
                BufferedImage in = ImageIO.read(path.toFile());
                if (in == null) return;
                BufferedImage out = brighten(in, factor);
                ImageIO.write(out, "png", outputFolder.resolve(path.getFileName()).toFile());
                i.incrementAndGet();
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
        System.out.println("wrote " + i + " files");
    }

    private BufferedImage brighten(BufferedImage image, float factor) {
        try {
            float[] factors = new float[]{
                    factor, factor, factor, 1f
            };
            float[] offsets = new float[]{
                    0.0f, 0.0f, 0.0f, 0.0f
            };
            RescaleOp op = new RescaleOp(factors, offsets, null);
            return op.filter(image, null);
        } catch (IllegalArgumentException ex) {
            float[] factors = new float[]{
                    1.4f, 1.4f, 1.4f
            };
            float[] offsets = new float[]{
                    0.0f, 0.0f, 0.0f
            };
            RescaleOp op = new RescaleOp(factors, offsets, null);
            return op.filter(image, null);
        }
    }
}