public File requestSave(String embeddedName) throws IOException {
            String suffix = ".tika";

            int splitAt = embeddedName.lastIndexOf('.');
            if (splitAt > 0) {
                embeddedName = embeddedName.substring(splitAt);
            }

            File tmp = Files
                    .createTempFile("tika-embedded-", suffix)
                    .toFile();
            wanted.put(embeddedName, tmp);
            return tmp;
        }
A recursive parser that saves certain images into the temporary
directory, and delegates everything else to another downstream
parser.
tika-app/src/main/java/org/apache/tika/gui/TikaGUI.java