TIFF Metadata Format Specification and Usage Notes

If the source image data have photometric type CIE L*a*b* or YCbCr, and the destination color space type is RGB, then the source image data will be automatically converted to RGB using an internal color converter.

If the data are known to be in a color space not correctly handled by the foregoing, then an ImageTypeSpecifier should be supplied to the reader and should be derived from a color space which is correct for the data in question.

    ImageInputStream input;
    ImageReader tiffReader;
    ImageReadParam tiffReadParam;

    tiffReader.setInput(input);

    // Read primary image and IFD.
    BufferedImage image = tiffReader.read(0, tiffReadParam);
    IIOMetadata primaryIFD = tiffReader.getImageMetadata(0);

    // Read thumbnail if present.
    BufferedImage thumbnail = null;
    if (tiffReader.getNumImages(true) > 1) {
        thumbnail = tiffReader.read(1, tiffReadParam);
    }

The parameter content of the APP1 marker segment may be obtained from the user object of the associated Node in a javax_imageio_jpeg_image_1.0 native image metadata tree extracted from the image metadata object returned by the JPEG reader. This APP1 Exif node will be a child of the node named "markerSequence" and will have name unknown and an attribute named MarkerTag with integral value 0xE1 (String value "225"). The user object of this node will be a byte array which starts with the six bytes {'E', 'x', 'i', 'f', '0', '0'}. The primary IFD and the thumbnail IFD and image may be read from the user object by the usual ImageReader methods:

    ImageReader jpegReader;
    ImageReader tiffReader;

    // Obtain the APP1 Exif marker data from the JPEG image metadata.
    IIOMetadata jpegImageMetadata = jpegReader.getImageMetadata(0);
    String nativeFormat = jpegImageMetadata.getNativeMetadataFormatName();
    Node jpegImageMetadataTree = jpegImageMetadata.getAsTree(nativeFormat);

    // getExifMarkerData() returns the byte array which is the user object
    // of the APP1 Exif marker node.
    byte[] app1Params = getExifMarkerData(jpegImageMetadataTree);
    if (app1Params == null) {
        throw new IIOException("APP1 Exif marker not found.");
    }

    // Set up input, skipping Exif ID 6-byte sequence.
    MemoryCacheImageInputStream app1ExifInput
        = new MemoryCacheImageInputStream
            (new ByteArrayInputStream(app1Params, 6, app1Params.length - 6));
    tiffReader.setInput(app1ExifInput);

    // Read primary IFD.
    IIOMetadata primaryIFD = tiffReader.getImageMetadata(0);

    // Read thumbnail if present.
    BufferedImage thumbnail = null;
    if (tiffReader.getNumImages(true) > 1) {
        thumbnail = tiffReader.read(1, tiffReadParam);
    }

    // Read the primary image.
    BufferedImage image = jpegReader.read(0);

Old-style JPEG compression as described in section 22 of the TIFF 6.0 Specification is not supported.

The CCITT compression types are applicable to bilevel (1-bit) images only. The JPEG compression type is applicable to byte grayscale (1-band) and RGB (3-band) images only.

ZLib and Deflate compression are identical except for the value of the TIFF Compression field: for ZLib the Compression field has value 8 whereas for Deflate it has value 32946 (0x80b2). In both cases each image segment (strip or tile) is written as a single complete zlib data stream.

"Exif JPEG" is a compression type used when writing the contents of an APP1 Exif marker segment for inclusion in a JPEG native image metadata tree. The contents appended to the output when this compression type is used are a function of whether an empty or non-empty image is written. If the image is empty, then a TIFF IFD adhering to the specification of a compressed Exif primary IFD is appended. If the image is non-empty, then a complete IFD and image adhering to the specification of a compressed Exif thumbnail IFD and image are appended. Note that the data of the empty image may not later be appended using the pixel replacement capability of the TIFF writer.

If ZLib/Deflate or JPEG compression is used, the compression quality may be set. For ZLib/Deflate the supplied floating point quality value is rescaled to the range [1, 9] and truncated to an integer to derive the Deflate compression level. For JPEG the floating point quality value is passed directly to the JPEG writer plug-in which interprets it in the usual way.

If the source image data color space type is RGB, and the destination photometric type is CIE L*a*b* or YCbCr, then the source image data will be automatically converted from RGB using an internal color converter.

For bilevel images, the FillOrder, and T4Options fields affect the output data. The data will be filled right-to-left if FillOrder is present with a value of 2 (BaselineTIFFTagSet.FILL_ORDER_RIGHT_TO_LEFT) and will be filled left-to-right otherwise. The value of T4Options specifies whether the data should be 1D- or 2D-encoded and whether EOL padding should be used.

For all images the value of the RowsPerStrip field is used to the set the number of rows per strip if the image is not tiled. The default number of rows per strip is either 8 or the number of rows which would fill no more than 8 kilobytes, whichever is larger.

For all images the tile dimensions may be set using the TileWidth and TileLength field values if the tiling mode is ImageWriteParam.MODE_COPY_FROM_METADATA. If this mode is set but the fields are not, their respective default values are the image width and height.

When using JPEG-in-TIFF compression, a JPEGTables field will be written to the IFD and abbreviated JPEG streams to each strip or tile if and only if a JPEGTables field is contained in the metadata object provided to the writer. If the contents of the JPEGTables field is a valid tables-only JPEG stream, then it will be used; otherwise the contents of the field will be replaced with default visually lossless tables. If no such JPEGTables field is present in the metadata, then no JPEGTables field will be written to the output and each strip or tile will be written as a separate, self-contained JPEG stream.

When using Deflate/ZLib or LZW compression, if the image has 8 bits per sample, a horizontal differencing predictor will be used if the Predictor field is present with a value of 2 (BaselineTIFFTagSet.PREDICTOR_HORIZONTAL_DIFFERENCING). If prediction is so requested but the image does not have 8 bits per sample the field will be reset to have the value 1 (BaselineTIFFTagSet.PREDICTOR_NONE).

Some fields may be added or modified:

• PhotometricInterpretation if not present.
• PlanarConfiguration if this field is present with value Planar is is reset to Chunky.
• Compression always.
• BitsPerSample if the image is not bilevel.
• SamplesPerPixel always.
• ExtraSamples if an alpha channel is present.
• SampleFormat if not present and the data are 16- or 32-bit integers or floating point.
• ColorMap if the PhotometricInterpretation is RGBPalette.
• ImageWidth and ImageLength always.
• TileWidth, TileLength, TileOffsets, and TileByteCounts if a tiled image is being written.
• RowsPerStrip, StripOffsets, and StripByteCounts if a tiled image is not being written.
• XResolution, YResolution, and ResolutionUnit if none of these is present.
• YCbCrSubsampling and YCbCrPositioning if the photometric interpretation is YCbCr and the compression type is not JPEG (only [1, 1] subsampling and cosited positioning are supported for non-JPEG YCbCr output).
• YCbCrSubsampling, YCbCrPositioning, and ReferenceBlackWhite: if the compression type is JPEG and the color space is RGB these will be reset to [2, 2] centered subsampling with no headroom/footroom (0:255,128:255,128:255).

Some fields may be removed:

• BitsPerSample if the image is bilevel.
• ExtraSamples if the image does not have an alpha channel.
• ColorMap if the photometric interpretation is not RGBPalette.
• TileWidth, TileLength, TileOffsets, and TileByteCounts if tiling is not being used.
• RowsPerStrip, StripOffsets, and StripByteCounts if tiling is being used.
• YCbCrSubsampling, YCbCrPositioning, and ReferenceBlackWhite if the compression type is JPEG and the color space is grayscale.
• JPEGProc, JPEGInterchangeFormat, JPEGInterchangeFormatLength, JPEGRestartInterval, JPEGLosslessPredictors, JPEGPointTransforms, JPEGQTables, JPEGDCTables, and JPEGACTables if the compression type is JPEG.

Other fields present in the supplied metadata are uninterpreted and will be written as supplied.

If an Exif image is being written, the set of fields present and their values will be modified such that the result is in accord with the Exif 2.2 specification.

    ImageWriter tiffWriter;
    ImageWriteParam tiffWriteParam;
    IIOMetadata tiffStreamMetadata;
    IIOMetadata primaryIFD;
    BufferedImage image;
    BufferedImage thumbnail;

    // Specify uncompressed output.
    tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED);

    if (thumbnail != null) {
        // Write the TIFF header.
        tiffWriter.prepareWriteSequence(tiffStreamMetadata);

        // Append the primary IFD.
        tiffWriter.prepareInsertEmpty(-1, // append
                new ImageTypeSpecifier(image),
                image.getWidth(),
                image.getHeight(),
                primaryIFD,
                null, // thumbnails
                tiffWriteParam);
        tiffWriter.endInsertEmpty();

        // Append the thumbnail image data.
        tiffWriter.writeToSequence(new IIOImage(thumbnail, null, null),
                tiffWriteParam);

        // Insert the primary image data.
        tiffWriter.prepareReplacePixels(0, new Rectangle(image.getWidth(),
                image.getHeight()));
        tiffWriter.replacePixels(image, tiffWriteParam);
        tiffWriter.endReplacePixels();

        // End writing.
        tiffWriter.endWriteSequence();
    } else {
        // Write only the primary IFD and image data.
        tiffWriter.write(tiffStreamMetadata,
                new IIOImage(image, null, primaryIFD),
                tiffWriteParam);
    }

<!DOCTYPE "javax_imageio_tiff_stream_1.0" [

  <!ELEMENT "javax_imageio_tiff_stream_1.0" (ByteOrder)>

    <!ELEMENT "ByteOrder" EMPTY>
      <!-- The stream byte order --> 
      <!ATTLIST "ByteOrder" "value" #CDATA #REQUIRED>
        <!-- One of "BIG_ENDIAN" or "LITTLE_ENDIAN" --> 
        <!-- Data type: String -->
]>

<!DOCTYPE "javax_imageio_tiff_image_1.0" [

  <!ELEMENT "javax_imageio_tiff_image_1.0" (TIFFIFD)*>

    <!ELEMENT "TIFFIFD" (TIFFField | TIFFIFD)*>
      <!-- An IFD (directory) containing fields --> 
      <!ATTLIST "TIFFIFD" "tagSets" #CDATA #REQUIRED>
        <!-- Data type: String -->
      <!ATTLIST "TIFFIFD" "parentTagNumber" #CDATA #IMPLIED>
        <!-- The tag number of the field pointing to this IFD --> 
        <!-- Data type: Integer -->
      <!ATTLIST "TIFFIFD" "parentTagName" #CDATA #IMPLIED>
        <!-- A mnemonic name for the field pointing to this IFD, if known 
             --> 
        <!-- Data type: String -->

      <!ELEMENT "TIFFField" (TIFFBytes | TIFFAsciis |
        TIFFShorts | TIFFSShorts | TIFFLongs | TIFFSLongs |
        TIFFRationals | TIFFSRationals |
        TIFFFloats | TIFFDoubles | TIFFUndefined)>
        <!-- A field containing data --> 
        <!ATTLIST "TIFFField" "number" #CDATA #REQUIRED>
          <!-- The tag number asociated with the field --> 
          <!-- Data type: String -->
        <!ATTLIST "TIFFField" "name" #CDATA #IMPLIED>
          <!-- A mnemonic name associated with the field, if known --> 
          <!-- Data type: String -->

        <!ELEMENT "TIFFBytes" (TIFFByte)*>
          <!-- A sequence of TIFFByte nodes --> 

          <!ELEMENT "TIFFByte" EMPTY>
            <!-- An integral value between 0 and 255 --> 
            <!ATTLIST "TIFFByte" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->
            <!ATTLIST "TIFFByte" "description" #CDATA #IMPLIED>
              <!-- A description, if available --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFAsciis" (TIFFAscii)*>
          <!-- A sequence of TIFFAscii nodes --> 

          <!ELEMENT "TIFFAscii" EMPTY>
            <!-- A String value --> 
            <!ATTLIST "TIFFAscii" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFShorts" (TIFFShort)*>
          <!-- A sequence of TIFFShort nodes --> 

          <!ELEMENT "TIFFShort" EMPTY>
            <!-- An integral value between 0 and 65535 --> 
            <!ATTLIST "TIFFShort" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->
            <!ATTLIST "TIFFShort" "description" #CDATA #IMPLIED>
              <!-- A description, if available --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFSShorts" (TIFFSShort)*>
          <!-- A sequence of TIFFSShort nodes --> 

          <!ELEMENT "TIFFSShort" EMPTY>
            <!-- An integral value between -32768 and 32767 --> 
            <!ATTLIST "TIFFSShort" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->
            <!ATTLIST "TIFFSShort" "description" #CDATA #IMPLIED>
              <!-- A description, if available --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFLongs" (TIFFLong)*>
          <!-- A sequence of TIFFLong nodes --> 

          <!ELEMENT "TIFFLong" EMPTY>
            <!-- An integral value between 0 and 4294967295 --> 
            <!ATTLIST "TIFFLong" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->
            <!ATTLIST "TIFFLong" "description" #CDATA #IMPLIED>
              <!-- A description, if available --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFSLongs" (TIFFSLong)*>
          <!-- A sequence of TIFFSLong nodes --> 

          <!ELEMENT "TIFFSLong" EMPTY>
            <!-- An integral value between -2147483648 and 2147482647 --> 
            <!ATTLIST "TIFFSLong" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->
            <!ATTLIST "TIFFSLong" "description" #CDATA #IMPLIED>
              <!-- A description, if available --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFRationals" (TIFFRational)*>
          <!-- A sequence of TIFFRational nodes --> 

          <!ELEMENT "TIFFRational" EMPTY>
            <!-- A rational value consisting of an unsigned numerator and 
                 denominator --> 
            <!ATTLIST "TIFFRational" "value" #CDATA #IMPLIED>
              <!-- The numerator and denominator, separated by a slash --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFSRationals" (TIFFSRational)*>
          <!-- A sequence of TIFFSRational nodes --> 

          <!ELEMENT "TIFFSRational" EMPTY>
            <!-- A rational value consisting of a signed numerator and 
                 denominator --> 
            <!ATTLIST "TIFFSRational" "value" #CDATA #IMPLIED>
              <!-- The numerator and denominator, separated by a slash --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFFloats" (TIFFFloat)*>
          <!-- A sequence of TIFFFloat nodes --> 

          <!ELEMENT "TIFFFloat" EMPTY>
            <!-- A single-precision floating-point value --> 
            <!ATTLIST "TIFFFloat" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFDoubles" (TIFFDouble)*>
          <!-- A sequence of TIFFDouble nodes --> 

          <!ELEMENT "TIFFDouble" EMPTY>
            <!-- A double-precision floating-point value --> 
            <!ATTLIST "TIFFDouble" "value" #CDATA #IMPLIED>
              <!-- The value --> 
              <!-- Data type: String -->

        <!ELEMENT "TIFFUndefined" EMPTY>
          <!-- Uninterpreted byte data --> 
          <!ATTLIST "TIFFUndefined" "value" #CDATA #IMPLIED>
            <!-- A list of comma-separated byte values --> 
            <!-- Data type: String -->
]>