GrayScaleImaging

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class GrayScaleImaging {
    public static void main(String[] args)
            throws IOException {

        //works
        final File inputFile = new File("/home/vinayb/Downloads/page1_color.tif");
        final File outputFile = new File("/home/vinayb/Downloads/page1_color_mod.tif");

        //doesn't work
//        final File inputFile = new File("/home/vinayb/Downloads/page1_grayscale.tif");
//        final File outputFile = new File("/home/vinayb/Downloads/page1_grayscale_mod.tif");
        if (outputFile.exists()) {
            outputFile.delete();
        }

        ImageReader imageReader = null;
        ImageWriter imageWriter = null;
        Graphics2D g = null;

        try (final ImageInputStream imageInputStream = ImageIO.createImageInputStream(inputFile);
             final ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(outputFile);) {


            //setup reader
            imageReader = ImageIO.getImageReaders(imageInputStream).next();
            imageReader.setInput(imageInputStream);

            //read image
            final BufferedImage bufferedImage = imageReader.read(0);

            //prepare graphics for the output
            g = bufferedImage.createGraphics();

            //draw image
            g.drawImage(bufferedImage, 0, 0, bufferedImage.getWidth(), bufferedImage.getHeight(), null);

            //setup writer based on reader
            imageWriter = ImageIO.getImageWriter(imageReader);
            imageWriter.setOutput(imageOutputStream);

            //write
            imageWriter.write(null, new IIOImage(bufferedImage, null, imageReader.getImageMetadata(0)), imageWriter.getDefaultWriteParam());
        } finally {
            //cleanup

            if (imageWriter != null) {
                imageWriter.dispose();
            }

            if (imageReader != null) {
                imageReader.dispose();
            }

            if (g != null) {
                g.dispose();
            }
        }
    }
}