import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.*;
import javax.imageio.stream.FileImageOutputStream;
/** Convert capture PNGs to JPEG (the figures' inputs do not need to be lossless). */
public class RawJpeg {
    public static void main(String[] a) throws Exception {
        for (String n : a) {
            BufferedImage src = ImageIO.read(new File(n));
            // screencap PNGs carry an alpha channel; JPEG cannot take that colorspace
            BufferedImage im = new BufferedImage(
                    src.getWidth(), src.getHeight(), BufferedImage.TYPE_INT_RGB);
            im.createGraphics().drawImage(src, 0, 0, null);
            String out = n.replace(".png", ".jpg");
            ImageWriter w = ImageIO.getImageWritersByFormatName("jpeg").next();
            ImageWriteParam p = w.getDefaultWriteParam();
            p.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
            p.setCompressionQuality(0.88f);
            try (FileImageOutputStream os = new FileImageOutputStream(new File(out))) {
                w.setOutput(os);
                w.write(null, new IIOImage(im, null, null), p);
            }
            w.dispose();
            System.out.println(out + " " + new File(out).length() / 1024 + " KB");
        }
    }
}