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);
}
