public void handle(Directory directory, Metadata metadata) throws MetadataException {
            // The test TIFF has width and height stored as follows according to exiv2
            //Exif.Image.ImageWidth                        Short       1  100
            //Exif.Image.ImageLength                       Short       1  75
            // and the values are found in "Thumbnail Image Width" (and Height)
            // from Metadata Extractor
            set(directory, metadata, JpegDirectory.TAG_IMAGE_WIDTH, Metadata.IMAGE_WIDTH);
            set(directory, metadata, JpegDirectory.TAG_IMAGE_HEIGHT, Metadata.IMAGE_LENGTH);
            // Bits per sample, two methods of extracting, exif overrides jpeg
            set(directory, metadata, JpegDirectory.TAG_DATA_PRECISION, Metadata.BITS_PER_SAMPLE);
            set(directory, metadata, ExifSubIFDDirectory.TAG_BITS_PER_SAMPLE,
                    Metadata.BITS_PER_SAMPLE);
            // Straightforward
            set(directory, metadata, ExifSubIFDDirectory.TAG_SAMPLES_PER_PIXEL,
                    Metadata.SAMPLES_PER_PIXEL);
        }
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