public void write(OutputStream os) throws IOException { ensureDataRead(); IOUtils.write(os, majorVersion); IOUtils.write(os, minorVersion); IOUtils.write(os, densityUnit); IOUtils.writeShortMM(os, getXDensity()); IOUtils.writeShortMM(os, getYDensity()); IOUtils.write(os, thumbnailWidth); IOUtils.write(os, thumbnailHeight); if (containsThumbnail) thumbnail.write(os); }