public void handle(Directory directory, Metadata metadata) throws MetadataException {
            if (directory.containsTag(JpegCommentDirectory.TAG_COMMENT)) {
                metadata.add(TikaCoreProperties.COMMENTS,
                        directory.getString(JpegCommentDirectory.TAG_COMMENT));
            }
        }
Basic image properties for TIFF and JPEG, at least.
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-image-module/src/main/java/org/apache/tika/parser/image/ImageMetadataExtractor.java