+JPEG Metadata
+Abbreviated Streams
+Sources of Tables
+Colorspace Transformations and Conventional Markers
+Thumbnail Images
+Progressive Encoding
+Native Metadata Format Tree Structure and Editing
+Image Metadata DTD
+Stream Metadata DTD
+
+dispose()
+on the JPEG reader and writer objects when they are no longer needed, as
+they consume significant native resources which are not adequately recovered
+by garbage collection. Both reader and writer call dispose()
+in their finalizers, but those finalizers may not be called before the native
+code has exhausted native memory.
+
+
+ +The JPEG writer does not support replacing pixels. + +
+
SOI marker and
+the EOI marker for that image. The image metadata object
+passed into a write determines the contents of the stream between the
+SOI marker and the EOI marker for that image,
+subject to the controls in any ImageWriteParam.
+
+
+Stream metadata is used only for tables-only images found (or to be
+placed) at the beginning of a stream containing abbreviated images.
+Tables-only images are not treated as images and do not consume an
+image index. The stream metadata object returned from a read describes the
+contents of the marker segments between the SOI marker and
+the EOI marker for the single tables-only image at the
+beginning of the stream, if one is present. If no tables-only image is
+present at the front of the stream, the getStreamMetadata
+method of ImageReader returns null. If
+stream metadata is provided to the writer, a single tables-only image
+containing the tables from the stream metadata object will be written at
+the beginning of the stream. If the stream metadata object contains no
+tables, default tables will be written. As the sole purpose of stream
+metadata is for specifying tables-only images at the front of abbreviated
+streams, the stream metadata argument is useful only on the
+ImageWriter.prepareWriteSequence method. It is ignored on all
+other methods.
+
+
+The ImageWriter.getDefaultStreamMetadata method returns an
+object containing the tables from the ImageWriteParam argument,
+if it is a JPEGImageWriteParam and contains tables. Otherwise,
+the returned object will contain default tables.
+
+
The ImageWriter.getDefaultImageMetadata method returns a
+metadata object containing ImageWriteParam argument contains tables. Otherwise the
+returned metadata object will contain default visually lossless tables.
+Of course, only a JPEGImageWriteParam may contain tables.
+
+
+If ignoreMetadata is set to true when the input
+is set on the reader, stream metadata will not be available, but image
+metadata will.
+
+
+
IllegalArgumentException is thrown.+Note that once a tables-only image has been read, it's contents is available +as stream metadata from the reader until either another tables-only image +is read from another stream or the reader is reset. Changing the input does +not reset the stream metadata. This is useful for reading the tables from +one file, then changing the input to read an abbreviated stream containing +a sequence of images. The tables will be used automatically, and will remain +available as "stream" metadata. + +
+Abbreviated streams are written using the sequence methods of
+ImageWriter. Stream metadata is used to write a tables-only
+image at the beginning of the stream, and the tables are set up for use, using
+ImageWriter.prepareWriteSequence. If no stream metadata is
+supplied to ImageWriter.prepareWriteSequence, then no
+tables-only image is written. If stream metadata containing no tables is
+supplied to ImageWriter.prepareWriteSequence, then a tables-only
+image containing default visually lossless tables is written.
+
+
+Images are written with tables if tables are present in their metadata objects +or without them if no tables are present in their metadata objects. If no +metadata object is present then the tables are written. The tables used for +compression are taken from one of the following sources, which are consulted +in order: +
ImageWriteParam and the compression mode is
+ set to EXPLICIT, default tables constructed using the
+ quality setting are used. They are written only if the metadata
+ contains tables or if there is no metadata, but they replace the
+ tables in the metadata.ImageWriteParam and the compression mode is
+ set to DEFAULT, default visually lossles tables are used.
+ They are written only if the metadata contains tables or if
+ there is no metadata, but they replace the tables in the
+ metadata.ImageWriteParam must
+ be MODE_COPY_FROM_METADATA, in which case the following
+ are used:
+ JPEGImageWriteParam, if presentJPEGImageWriteParams only as a means of specifying tables
+when no other source is available, and this can occur only when writing to an
+abbreviated stream without tables using known non-standard tables for
+compression.
+
+
+When reading, tables in a JPEGImageReadParam are consulted only
+if tables have not been set by any previous read. Tables set from a
+JPEGImageReadParam are overridden by any tables present in the
+stream being read.
+
+
+Note that if no image metadata object is specified for a particular image, a +default object is used, which includes default tables. + +
+
Rasters are
+read, no colorspace transformation is performed, and any destination type
+is ignored. A warning is sent to any listeners if a destination type is
+specified in this case. When Rasters are written, any
+destination type is used to interpret the bands. This might result in a
+JFIF or Adobe header being written, or different component ids being written
+to the frame and scan headers. If values present in a metadata object do not
+match the destination type, the destination type is used and a warning is sent
+to any listeners.
+
++ +When reading, the contents of the stream are interpreted by the usual +JPEG conventions, as follows: + +
APP0 marker segment is present, the colorspace
+ is known to be either grayscale or YCbCr. If an APP2
+ marker segment containing an embedded ICC profile is also present, then
+ the YCbCr is converted to RGB according to the formulas given in the
+ JFIF spec, and the ICC profile is assumed to refer to the resulting RGB
+ space.
+ +
APP14 marker segment is present, the
+ colorspace is determined by consulting the transform flag.
+ The transform flag takes one of three values:
+ +
+
RGB
+
RGBA
+
YCC (as 'Y','C','c'), assumed to be PhotoYCC
+
YCCA (as 'Y','C','c','A'), assumed to be PhotoYCCA
+
+ Otherwise, 3-channel subsampled images are assumed to be YCbCr, + 3-channel non-subsampled images are assumed to be RGB, 4-channel + subsampled images are assumed to be YCCK, and 4-channel, non-subsampled + images are assumed to be CMYK. + +
+
BufferedImage. Such an image may be read only as a
+ Raster. If an image is interpretable but there is no Java
+ ColorSpace available corresponding to the encoded
+ colorspace (ImageReader.getRawImageType will return null.
+ColorSpace or a custom RGB ColorSpace object
+ based on an embedded ICC profile is used to create the output
+ ColorModel. PhotoYCC and PhotoYCCA images are not
+ converted. CMYK and YCCK images are currently not supported.BufferedImage
+ (Rasters. If an image colorspace is unsupported or
+ uninterpretable, then ImageReader.getImageTypes will
+ return an empty Iterator. If a subset of the raw bands
+ are required, a Raster must be obtained first and the
+ bands obtained from that. +For writing, the color transformation to apply is determined as +follows: + +
+If a subset of the source bands is to be written, no color conversion is
+performed. Any destination, if set, must match the number of bands that will
+be written, and serves as an interpretation of the selected bands, rather than
+a conversion request. This behavior is identical to that for
+Rasters. If all the bands are to be written and an image
+(as opposed to a Raster) is being written, any destination type
+is ignored and a warning is sent to any listeners.
+
+
+If a destination type is used and any aspect of the metadata object, if there
+is one, is not compatible with that type, the destination type is used, the
+metadata written is modified from that provided, and a warning is sent to
+listeners. This includes the app0JFIF and
+app14Adobe nodes. The component ids in the sof and
+sos nodes are not modified, however, as unless a
+app0JFIF node is present, any values may be used.
+
+ +When a full image is written, a destination colorspace will be +chosen based on the image contents and the metadata settings, according to +the following algorithm: + +
+ +If no metadata object is specified, then the following defaults apply: + +
APP0 marker
+ segment. Grayscale images with alpha are written with no special
+ marker. As required by JFIF, the component ids in the frame and
+ scan header is set to 1.
+
+ APP0 marker segment. If the ColorSpace
+ of the image is based on an ICCProfile (it is an instance
+ of ICC_ColorSpace, but is not one of the standard built-in
+ ColorSpaces), then that profile is embedded in an
+ APP2 marker segment. As required by JFIF, the
+ component ids in the frame and scan headers are set to 1, 2, and 3.
+
+
+ APP14 marker segment and 'Y','C', and 'c' (and
+ 'A' if an alpha channel is present) as component ids in the frame
+ and scan headers.
+
+
+If a metadata object is specified, then the number of channels in the
+frame and scan headers must always match the number of bands to be
+written, or an exception is thrown. app0JFIF and
+app14Adobe nodes may appear in the same metadata object only
+if the app14Adobe node indicates YCbCr, and the component ids
+are JFIF compatible (0-2). The various image types are processed in the
+following ways:
+
+
+
+(All multi-channel images are subsampled according to the sampling factors
+in the frame header node of the metadata object, regardless of color space.)
+
+
app0JFIF node is present in the metadata object,
+ a JFIF APP0 marker segment is written.
+ app14Adobe node is present in the metadata
+ object, it is checked for validity (transform must be
+ UNKNOWN) and written.
+ app0JFIF node is present in the metadata object,
+ it is ignored and a warning is sent to listeners, as JFIF does not
+ support 2-channel images.
+ app14Adobe node is present in the metadata
+ object, it is checked for validity (transform must be
+ UNKNOWN) and written. If transform is
+ not UNKNOWN, a warning is sent to listeners and the
+ correct transform is written.
+ app0JFIF node is present in the metadata object,
+ the image is converted to YCbCr and written with a JFIF
+ APP0 marker segment. If the ColorSpace
+ of the image is based on a non-standard ICC Profile, then that
+ profile is embedded in an APP2 marker segment. If the
+ ColorSpace is not based on a non-standard ICC Profile,
+ but an app2ICC node appears in the metadata, then an
+ APP2 marker segment is written with the appropriate
+ standard profile. Note that the profile must specify an RGB color
+ space, as the file must be JFIF compliant.
+
+ app14Adobe node is present in the metadata
+ object, the image is converted according to the color transform
+ setting and written with an Adobe APP14 marker
+ segment. Component ids are written just as they appear in the
+ frame and scan headers. The color transform must be either YCbCr
+ or UNKNOWN. If it is UNKNOWN, the image
+ is not color converted.
+
+ app0JFIF node is present in the metadata object,
+ it is ignored and a warning is sent to listeners, as JFIF does not
+ support 4-channel images.
+
+ app14Adobe node is present in the metadata
+ object, the image is written with an Adobe APP14 marker
+ segment. No colorspace conversion is performed. Component ids
+ are written just as they appear in the frame and scan headers.
+ The color transform must be UNKNOWN. If it is
+ not, a warning is sent to listeners.
+
+ app14Adobe node is present, the component ids in
+ the frame header are consulted. If these indicate a colorspace as
+ described above, then the image is converted to that colorspace if
+ possible. If the component ids do not indicate a colorspace, then
+ the sampling factors are consulted. If the image is to be
+ subsampled, it is converted to YCbCrA. If the image is not to be
+ subsampled, then no conversion is applied. No special marker
+ segments are written.
+ app0JFIF node is present in the metadata object,
+ the image is converted to sRGB, and then to YCbCr during encoding,
+ and a JFIF APP0 marker segment is written.
+
+ app14Adobe node is present in the metadata
+ object, no conversion is applied, and an Adobe APP14
+ marker segment is written. The color transform must be YCC. If it
+ is not, a warning is sent to listeners.
+
+ app0JFIF node is present in the metadata object,
+ it is ignored and a warning is sent to listeners, as JFIF does not
+ support 4-channel images.
+
+ app14Adobe node is present in the metadata
+ object, no conversion is applied, and an Adobe APP14
+ marker segment is written. The color transform must be
+ UNKNOWN. If it is not, a warning is sent to
+ listeners.
+
+ +
app0JFIF and app0JFXX nodes present in
+the metadata do not contain any thumbnail pixel data. However, the kinds of
+thumbnails written depend on the contents of the metadata object, as follows.
+Any thumbnail which is to be written as an indexed or RGB image and which is
+larger than 255 by 255 will be clipped, not scaled, to 255 by 255. Thumbnails
+written as JPEG images may be any size. A warning is sent to any listeners
+whenever a thumbnail is clipped.
+app0JFXX node is present in the metadata, or
+ the first app0JFXX node present in the metadata
+ contains a JFIFthumbPalette element, a
+ palette thumbnail is written in a JFXX APP0 marker
+ segment.
+ app0JFXX node present in the metadata
+ contains another thumbnail form (RGB or JPEG), the palette
+ image is expanded to RGB and the indicated thumbnail form is
+ written.
+ app0JFXX node is present in the metadata,
+ the thumbnail is written as part of the JFIF APP0
+ marker segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbRGB element, an
+ RGB thumbnail is written in a JFXX APP0 marker
+ segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbJPEG element, a
+ JPEG thumbnail is written in a JFXX APP0 marker
+ segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbPalette element, an
+ RGB thumbnail is written in a JFXX APP0 marker
+ segment and a warning is sent to any listeners.
+ app0JFXX node is present in the metadata,
+ the thumbnail is expanded to RGB and written as part of the
+ JFIF APP0 marker segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbRGB element, the thumbnail is
+ expanded to RGB and written in a separate JFXX RGB
+ marker segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbJPEG element, a
+ JPEG thumbnail is written in a JFXX APP0 marker
+ segment.
+ app0JFXX node present in the metadata
+ contains a JFIFthumbPalette element, a
+ JPEG thumbnail is written in a JFXX APP0 marker
+ segment and a warning is sent to any listeners.
+ APP0 segment, and
+ the app0JFXX node consulted for each thumbnail is the
+ app0JFXX node from the metadata that occurs in the same
+ sequence as the thumbnail. app0JFXX node applies to the first thumbnail, the second
+ node to the second thumbnail, and so on. If there are fewer
+ app0JFXX nodes in the metadata than thumbnails, then
+ those thumbnails are considered to have no matching
+ app0JFXX node. An RGB thumbnail with no matching
+ app0JFXX node is written in a JFXX APP0 marker
+ segment. A grayscale thumbnail with no matching
+ app0JFXX node is written as a JPEG image to a JFXX
+ APP0 marker segment.
++ +Note that as the only mechanism for storing thumbnails is via the +JFIF or JFIF extension marker segments, only grayscale or RGB images +may have thumbnails. If thumbnails are present when writing any other type +of image, the thumbnails are ignored and a warning is sent to any warning +listeners. + +
+
ImageWriteParam
+passed in to a write operation, or the image will be written sequentially,
+regardless of the scan headers included in the metadata object. If
+progressive encoding is enabled and set to copy from metadata, then
+the sequence of scan headers from the metadata is used to write the
+image. If progressive encoding is enabled and set to use a default,
+then the scans in the metadata are ignored and a default set of scans
+is used. Progressive encoding always forces optimized Huffman tables to
+be used. Any Huffman tables present in the metadata will be ignored,
+and a warning will be sent to any warning listeners.
+
+If Huffman-table optimization is requested on the ImageWriteParam,
+all Huffman tables in the metadata or in the ImageWriteParam
+itself are ignored, and a warning will be sent to any warning listeners if
+any such tables are present.
+
++
IIOMetadata object. They do not include nodes
+corresponding to SOI, EOI, or RST
+markers, as these parsing delimiters do not carry any meaningful metadata.
+
+
+The first node is always a JPEGvariety node. In the
+javax_imageio_jpeg_image_1.0 version of the JPEG metadata
+format, this node may have one child, an app0JFIF node,
+indicating that the JPEG stream contains a JFIF marker segment and related
+data, or no children, indicating that the stream contains no JFIF marker.
+In future versions of the JPEG metadata format, other varieties of JPEG
+metadata may be supported (e.g. Exif) by defining other types of nodes
+which may appear as a child of the JPEGvariety node.
+
+
+(Note that an application wishing to interpret Exif metadata given
+a metadata tree structure in the javax_imageio_jpeg_image_1.0
+format must check for an unknown marker segment with a tag
+indicating an APP1 marker and containing data identifying it
+as an Exif marker segment. Then it may use application-specific code to
+interpret the data in the marker segment. If such an application were
+to encounter a metadata tree formatted according to a future version of
+the JPEG metadata format, the Exif marker segment might not be
+unknown in that format - it might be structured as a
+child node of the JPEGvariety node. Thus, it is important
+for an application to specify which version to use by passing the string
+identifying the version to the method/constructor used to obtain an
+IIOMetadata object.)
+
+
+
+On reading, JFXX and app2ICC nodes occur as
+children of an app0JFIF node.
+This is true regardless of where the JFXX APP0 and
+APP2 marker segments actually occur in the stream. The ordering
+of nodes within the markerSequence node corresponds to the
+ordering of marker segments found in the JPEG stream.
+
+On writing, any JFXX and app2ICC nodes must
+occur as children of an app0JFIF node, itself a child of a
+JPEGvariety node, which must always be the first node.
+(If the stream is not to be JFIF compliant, no app0JFIF node
+should be provided, and the JPEGvariety node should have no
+children.) Any
+JFIF APP0, JFXX APP0, and APP2 marker
+segments are written first, followed by all Adobe APP14,
+APPn, COM and unknown segments in the
+order in which their corresponding nodes appear in the
+markerSequence node, followed by DQT (and
+DHT for non-progressive writes) marker segments, followed by the
+SOF and SOS marker segments. For progressive writes
+using metadata to control progression, the SOS segments are used
+in the order in which their corresponding nodes occur in the
+markerSequence node.
+
+
+The reset, mergeTree and setFromTree
+operations have the following semantics for the JPEG plug-in metadata object:
+
+
reset - A call to reset will restore the
+metadata object to the same state it had immediately after creation, whether
+this came about from reading a stream or by obtaining a default object from
+the ImageWriter. This is true regardless of how many times the
+metadata object has been modified since creation.
+
+
mergeTree - Native Format
+
The mergeTree operation accepts valid trees conforming to
+the DTD below, and merges the nodes using the following ordering rules. In
+all cases, only data present in the new node is changed in a corresponding
+existing node, if any. This means that nodes cannot be removed using
+mergeTree. To remove nodes, use setFromTree. The
+tree must consist of IIOMetadataNodes.
+
app0JFIF
+ app0JFIF node already exists, the contents
+ of the new one modify the existing one.
+ dqt
+ dqt nodes in the sequence,
+ then each table in the node replaces the first table, in any
+ dqt node, with the same table id.
+ dqt nodes contain a table
+ with the same id, then the table is added to the last existing
+ dqt node.
+ dqt nodes, then a new one is
+ created and added as follows:
+ dht nodes, the new
+ dqt node is inserted before the first one.
+ dht nodes, the new
+ dqt node is inserted before an
+ sof node, if there is one.
+ sof node, the new
+ dqt node is inserted before the first
+ sos node, if there is one.
+ sos node, the new
+ dqt node is added to the end of the sequence.
+ dht
+ dht nodes in the sequence,
+ then each table in the node replaces the first table, in any
+ dht node, with the same table class and table id.
+ dht nodes contain a table
+ with the same class and id, then the table is added to the last
+ existing dht node.
+ dht nodes, then a new one is
+ created and added as follows:
+ dqt nodes, the new
+ dht node is inserted immediately following the
+ last dqt node.
+ dqt nodes, the new
+ dht node is inserted before an
+ sof node, if there is one.
+ sof node, the new
+ dht node is inserted before the first
+ sos node, if there is one.
+ sos node, the new
+ dht node is added to the end of the sequence.
+ dri
+ dri node, the restart
+ interval value is updated.
+ dri node, then a new one is created
+ and added as follows:
+ sof node, the new
+ dri node is inserted before it.
+ sof node, the new
+ dri node is inserted before the first
+ sos node, if there is one.
+ sos node, the new
+ dri node is added to the end of the sequence.
+ com
+ com node is created and inserted as follows:
+ com nodes, the new one is
+ inserted after the last one.
+ com nodes, the new
+ com node is inserted after the
+ app14Adobe node, if there is one.
+ app14Adobe node, the new
+ com node is inserted at the beginning of the
+ sequence.
+ app14Adobe
+ app14Adobe node, then
+ its attributes are updated from the node.
+ app14Adobe node, then a new one is
+ created and added as follows:
+ app14Adobe node is inserted after the
+ last unknown node, if there are any.
+ unknown nodes, the new
+ app14Adobe node is inserted at the beginning
+ of the sequence.
+ unknown
+ unknown node is created and added to the
+ sequence as follows:
+ unknown marker nodes, the
+ new one is inserted after the last one.
+ unknown nodes, the new
+ unknown node is inserted before the
+ app14Adobe node, if there is one.
+ app14Adobe node, the new
+ unknown node is inserted at the beginning of the
+ sequence.
+ sof
+ sof node in the
+ sequence, then its values are updated from the node.
+ sof node, then a new one is created
+ and added as follows:
+ sos nodes, the new
+ sof node is inserted before the first one.
+ sos node, the new
+ sof node is added to the end of the sequence.
+ sos
+ sos node, then
+ the values are updated from the node.
+ sos nodes,
+ then an IIOInvalidTreeException is thrown, as
+ sos nodes cannot be merged into a set of
+ progressive scans.
+ sos nodes, a new one is created
+ and added to the end of the sequence.
+ mergeTree - Standard Format
+
+The mergeTree operation, when given a tree in the standard
+format, will modify the native tree in the following ways:
+
Chroma - The ColorSpaceType subnode of a
+ Chroma node may change the target colorspace of the
+ compressed image. The selection of a new colorspace can cause a number
+ of changes, in keeping with the algorithms described above:
+ app0JFIF and app14Adobe nodes may be added
+ or removed, subsampling may be added or removed, component ids may
+ be changed, and sof and sos nodes will be
+ updated accordingly. If necessary, additional quantization and
+ huffman tables are added. In the case of quantization tables, the
+ default will be scaled to match the quality level of any existing
+ tables. No tables are added to metadata that does not already contain
+ tables. If the existing metadata specifies progressive encoding, then
+ the number of channels must not change. Any Transparency
+ node is also taken into account, as an explicit value of
+ none for the Alpha subnode can cause the
+ removal of an alpha channel, and anything other than none
+ can cause the addition of an alpha channel.
+ Dimension - A PixelAspectRatio specification
+ can cause the contents of an app0JFIF node to change, if
+ there is one present, or the addition of an app0JFIF node
+ containing appropriate values, if there can be one. An appropriate
+ pair of integers is computed from the floating-point ratio for
+ inclusion in the node.
+ Text - Each uncompressed text item is converted to a
+ com node and inserted according to the rules above for
+ merging com nodes.
+ setFromTree - Native Format
+
+The setFromTree operation, when given a tree in the native
+format described below, will simply replace the existing tree in its entirety
+with the new one. The tree must consist of IIOMetadataNodes.
+
+
setFromTree - Standard Format
+
+The setFromTree operation, when given a tree in the standard
+format, performs a reset followed by a merge of the new tree.
+
+
+<!DOCTYPE "javax_imageio_jpeg_image_1.0" [
+
+ <!ELEMENT "javax_imageio_jpeg_image_1.0" (JPEGvariety, markerSequence)>
+
+ <!ELEMENT "JPEGvariety" (app0JFIF)>
+ <!-- A node grouping all marker segments specific to the variety of
+ stream being read/written (e.g. JFIF) - may be empty -->
+
+ <!ELEMENT "app0JFIF" (JFXX?, app2ICC?)>
+ <!ATTLIST "app0JFIF" "majorVersion" #CDATA "1">
+ <!-- The major JFIF version number -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "app0JFIF" "minorVersion" #CDATA "2">
+ <!-- The minor JFIF version number -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "app0JFIF" "resUnits" ("0" | "1" | "2") "0">
+ <!-- The resolution units for Xdensisty and Ydensity (0 = no
+ units, just aspect ratio; 1 = dots/inch; 2 = dots/cm) -->
+ <!ATTLIST "app0JFIF" "Xdensity" #CDATA "1">
+ <!-- The horizontal density or aspect ratio numerator -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 1 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "app0JFIF" "Ydensity" #CDATA "1">
+ <!-- The vertical density or aspect ratio denominator -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 1 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "app0JFIF" "thumbWidth" #CDATA "0">
+ <!-- The width of the thumbnail, or 0 if there isn't one -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "app0JFIF" "thumbHeight" #CDATA "0">
+ <!-- The height of the thumbnail, or 0 if there isn't one -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+
+ <!ELEMENT "JFXX" (app0JFXX)*>
+ <!-- Min children: 1 -->
+
+ <!ELEMENT "app0JFXX" (JFIFthumbJPEG | JFIFthumbPalette |
+ JFIFthumbRGB)>
+ <!-- A JFIF extension marker segment -->
+ <!ATTLIST "app0JFXX" "extensionCode" ("16" | "17" | "19")
+ #IMPLIED>
+ <!-- The JFXX extension code identifying thumbnail type: (16 =
+ JPEG, 17 = indexed, 19 = RGB -->
+
+ <!ELEMENT "JFIFthumbJPEG" (markerSequence?)>
+ <!-- A JFIF thumbnail in JPEG format (no JFIF segments
+ permitted) -->
+
+ <!ELEMENT "JFIFthumbPalette" EMPTY>
+ <!-- A JFIF thumbnail as an RGB indexed image -->
+ <!ATTLIST "JFIFthumbPalette" "thumbWidth" #CDATA #IMPLIED>
+ <!-- The width of the thumbnail -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "JFIFthumbPalette" "thumbHeight" #CDATA #IMPLIED>
+ <!-- The height of the thumbnail -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+
+ <!ELEMENT "JFIFthumbRGB" EMPTY>
+ <!-- A JFIF thumbnail as an RGB image -->
+ <!ATTLIST "JFIFthumbRGB" "thumbWidth" #CDATA #IMPLIED>
+ <!-- The width of the thumbnail -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "JFIFthumbRGB" "thumbHeight" #CDATA #IMPLIED>
+ <!-- The height of the thumbnail -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+
+ <!ELEMENT "app2ICC" EMPTY>
+ <!-- An ICC profile APP2 marker segment -->
+ <!-- Optional User object: java.awt.color.ICC_Profile -->
+
+ <!ELEMENT "markerSequence" (dqt | dht | dri | com | unknown |
+ app14Adobe | sof | sos)*>
+ <!-- A node grouping all non-jfif marker segments -->
+
+ <!ELEMENT "dqt" (dqtable)*>
+ <!-- A Define Quantization Table(s) marker segment -->
+ <!-- Min children: 1 -->
+ <!-- Max children: 4 -->
+
+ <!ELEMENT "dqtable" EMPTY>
+ <!-- A single quantization table -->
+ <!-- User object: javax.imageio.plugins.jpeg.JPEGQTable -->
+ <!ATTLIST "dqtable" "elementPrecision" #CDATA "0">
+ <!-- The number of bits in each table element (0 = 8, 1 = 16)
+ -->
+ <!-- Data type: Integer -->
+ <!ATTLIST "dqtable" "qtableId" ("0" | "1" | "2" | "3") #REQUIRED>
+
+ <!ELEMENT "dht" (dhtable)*>
+ <!-- A Define Huffman Table(s) marker segment -->
+ <!-- Min children: 1 -->
+ <!-- Max children: 4 -->
+
+ <!ELEMENT "dhtable" EMPTY>
+ <!-- A single Huffman table -->
+ <!-- User object: javax.imageio.plugins.jpeg.JPEGHuffmanTable -->
+ <!ATTLIST "dhtable" "class" ("0" | "1") #REQUIRED>
+ <!-- Indicates whether this is a DC (0) or an AC (1) table -->
+ <!ATTLIST "dhtable" "htableId" ("0" | "1" | "2" | "3") #REQUIRED>
+ <!-- The table id -->
+
+ <!ELEMENT "dri" EMPTY>
+ <!-- A Define Restart Interval marker segment -->
+ <!ATTLIST "dri" "interval" #CDATA #REQUIRED>
+ <!-- The restart interval in MCUs -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+
+ <!ELEMENT "com" EMPTY>
+ <!-- A Comment marker segment. The user object contains the actual
+ bytes. -->
+ <!-- User object: array of [B -->
+ <!-- Min length: 1 -->
+ <!-- Max length: 65533 -->
+ <!ATTLIST "com" "comment" #CDATA #IMPLIED>
+ <!-- The comment as a string (used only if user object is null)
+ -->
+ <!-- Data type: String -->
+
+ <!ELEMENT "unknown" EMPTY>
+ <!-- An unrecognized marker segment. The user object contains the
+ data not including length. -->
+ <!-- User object: array of [B -->
+ <!-- Min length: 1 -->
+ <!-- Max length: 65533 -->
+ <!ATTLIST "unknown" "MarkerTag" #CDATA #REQUIRED>
+ <!-- The tag identifying this marker segment -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+
+ <!ELEMENT "app14Adobe" EMPTY>
+ <!-- An Adobe APP14 marker segment -->
+ <!ATTLIST "app14Adobe" "version" #CDATA "100">
+ <!-- The version of Adobe APP14 marker segment -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 100 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "app14Adobe" "flags0" #CDATA "0">
+ <!-- The flags0 variable of an APP14 marker segment -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "app14Adobe" "flags1" #CDATA "0">
+ <!-- The flags1 variable of an APP14 marker segment -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "app14Adobe" "transform" ("0" | "1" | "2") #REQUIRED>
+ <!-- The color transform applied to the image (0 = Unknown, 1 =
+ YCbCr, 2 = YCCK) -->
+
+ <!ELEMENT "sof" (componentSpec)*>
+ <!-- A Start Of Frame marker segment -->
+ <!-- Min children: 1 -->
+ <!-- Max children: 4 -->
+ <!ATTLIST "sof" "process" ("0" | "1" | "2") #IMPLIED>
+ <!-- The JPEG process (0 = Baseline sequential, 1 = Extended
+ sequential, 2 = Progressive) -->
+ <!ATTLIST "sof" "samplePrecision" #CDATA "8">
+ <!-- The number of bits per sample -->
+ <!-- Data type: Integer -->
+ <!ATTLIST "sof" "numLines" #CDATA #IMPLIED>
+ <!-- The number of lines in the image -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "sof" "samplesPerLine" #CDATA #IMPLIED>
+ <!-- The number of samples per line -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 65535 (inclusive) -->
+ <!ATTLIST "sof" "numFrameComponents" ("1" | "2" | "3" | "4")
+ #IMPLIED>
+ <!-- The number of components in the image -->
+
+ <!ELEMENT "componentSpec" EMPTY>
+ <!-- A component specification for a frame -->
+ <!ATTLIST "componentSpec" "componentId" #CDATA #REQUIRED>
+ <!-- The id for this component -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "componentSpec" "HsamplingFactor" #CDATA #REQUIRED>
+ <!-- The horizontal sampling factor for this component -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 1 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "componentSpec" "VsamplingFactor" #CDATA #REQUIRED>
+ <!-- The vertical sampling factor for this component -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 1 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "componentSpec" "QtableSelector" ("0" | "1" | "2" |
+ "3") #REQUIRED>
+ <!-- The quantization table to use for this component -->
+
+ <!ELEMENT "sos" (scanComponentSpec)*>
+ <!-- A Start Of Scan marker segment -->
+ <!-- Min children: 1 -->
+ <!-- Max children: 4 -->
+ <!ATTLIST "sos" "numScanComponents" ("1" | "2" | "3" | "4")
+ #REQUIRED>
+ <!-- The number of components in the scan -->
+ <!ATTLIST "sos" "startSpectralSelection" #CDATA "0">
+ <!-- The first spectral band included in this scan -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 63 (inclusive) -->
+ <!ATTLIST "sos" "endSpectralSelection" #CDATA "63">
+ <!-- The last spectral band included in this scan -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 63 (inclusive) -->
+ <!ATTLIST "sos" "approxHigh" #CDATA "0">
+ <!-- The highest bit position included in this scan -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 15 (inclusive) -->
+ <!ATTLIST "sos" "approxLow" #CDATA "0">
+ <!-- The lowest bit position included in this scan -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 15 (inclusive) -->
+
+ <!ELEMENT "scanComponentSpec" EMPTY>
+ <!-- A component specification for a scan -->
+ <!ATTLIST "scanComponentSpec" "componentSelector" #CDATA
+ #REQUIRED>
+ <!-- The id of this component -->
+ <!-- Data type: Integer -->
+ <!-- Min value: 0 (inclusive) -->
+ <!-- Max value: 255 (inclusive) -->
+ <!ATTLIST "scanComponentSpec" "dcHuffTable" ("0" | "1" | "2" |
+ "3") #REQUIRED>
+ <!-- The huffman table to use for encoding DC coefficients -->
+ <!ATTLIST "scanComponentSpec" "acHuffTable" ("0" | "1" | "2" |
+ "3") #REQUIRED>
+ <!-- The huffman table to use for encoding AC coefficients -->
+]>
+
+
++<!DOCTYPE "javax_imageio_jpeg_stream_1.0" [ + <!ELEMENT "javax_imageio_jpeg_stream_1.0" (dqt | + dht | + dri | + com | + unknown)*> + + <!-- All elements are as defined above for image metadata --> +]> ++ + +