mirror of
https://github.com/HDFGroup/hdf5.git
synced 2024-11-27 02:10:55 +08:00
4146d79af1
Purpose:
Changed "HDF5 User's Guide" links (in navigation bars, primarily)
to point to new user's guide, which will reside for a while yet on
the HDF server.
The old user's guide will still go out with the distribution under
the label "HDF5 User's Guide, Release 1.4.5."
Platforms tested:
IE 5
1281 lines
32 KiB
HTML
Executable File
1281 lines
32 KiB
HTML
Executable File
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
|
<meta name="GENERATOR" content="Mozilla/4.72 [en] (WinNT; U) [Netscape]">
|
|
<title>Image Specification</title>
|
|
|
|
<!-- #BeginLibraryItem "/ed_libs/styles_Gen.lbi" -->
|
|
<!--
|
|
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
|
|
* Copyright by the Board of Trustees of the University of Illinois. *
|
|
* All rights reserved. *
|
|
* *
|
|
* This file is part of HDF5. The full HDF5 copyright notice, including *
|
|
* terms governing use, modification, and redistribution, is contained in *
|
|
* the files COPYING and Copyright.html. COPYING can be found at the root *
|
|
* of the source code distribution tree; Copyright.html can be found at the *
|
|
* root level of an installed copy of the electronic HDF5 document set and *
|
|
* is linked from the top-level documents page. It can also be found at *
|
|
* http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html. If you do not have *
|
|
* access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
|
|
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
|
|
-->
|
|
|
|
<link href="../ed_styles/GenElect.css" rel="stylesheet" type="text/css">
|
|
<!-- #EndLibraryItem --></head>
|
|
|
|
<body text="#000000" bgcolor="#FFFFFF" link="#0000EE" vlink="#551A8B" alink="#FF0000">
|
|
|
|
|
|
<!-- #BeginLibraryItem "/ed_libs/NavBar_ADevG.lbi" --><hr>
|
|
<center>
|
|
<table border=0 width=98%>
|
|
<tr><td valign=top align=left>
|
|
<a href="../index.html">HDF5 documents and links</a> <br>
|
|
<a href="../H5.intro.html">Introduction to HDF5</a> <br>
|
|
<!--
|
|
<a href="Glossary.html">Glossary</a><br>
|
|
-->
|
|
</td>
|
|
<td valign=top align=right>
|
|
<a href="http://hdf.ncsa.uiuc.edu/HDF5/doc/UG/index.html">HDF5 User's Guide</a> <br>
|
|
<a href="../RM_H5Front.html">HDF5 Reference Manual</a> <br>
|
|
<a href="../ADGuide.html">HDF5 Application Developer's Guide</a> <br>
|
|
</td></tr>
|
|
</table>
|
|
</center>
|
|
<hr>
|
|
<!-- #EndLibraryItem --><center>
|
|
<h1>
|
|
HDF5 Image and Palette Specification</h1></center>
|
|
|
|
<center>
|
|
<h3>
|
|
<i>Version 1.2</i></h3></center>
|
|
The HDF5 specification defines the standard objects and storage for the
|
|
standard HDF5 objects. (For information about the HDF5 library, model and
|
|
specification, see the HDF documentation.) This document is an additional
|
|
specification do define a standard profile for how to store image data
|
|
in HDF5. Image data in HDF5 is stored as HDF5 datasets with standard attributes
|
|
to define the properties of the image.
|
|
<p>This specification is primarily concerned with two dimensional raster
|
|
data similar to HDF4 Raster Images. Specifications for storing other
|
|
types of imagery will be covered in other documents.
|
|
<p>This specification defines:
|
|
<ul>
|
|
<li>
|
|
Standard storage and attributes for an Image dataset (<a href="#Sect1">Section
|
|
1</a>)</li>
|
|
|
|
<li>
|
|
Standard storage and attributes for Palettes (<a href="#sect2">Section
|
|
2</a>)</li>
|
|
|
|
<li>
|
|
Standard for associating Palettes with Images. (<a href="#Sect3">Section
|
|
3</a>)</li>
|
|
</ul>
|
|
|
|
<h2>
|
|
<a NAME="Sect1"></a>1. HDF5 Image Specification</h2>
|
|
|
|
<h3>
|
|
1.1 Overview</h3>
|
|
Image data is stored as an HDF5 dataset with values of HDF5 class Integer
|
|
or Float. A common example would be a two dimensional dataset, with
|
|
elements of class Integer, e.g., a two dimensional array of unsigned 8
|
|
bit integers. However, this specification does not limit the dimensions
|
|
or number type that may be used for an Image.
|
|
<p>The dataset for an image is distinguished from other datasets by giving
|
|
it an attribute "CLASS=IMAGE". In addition, the Image dataset may
|
|
have an optional attribute "PALETTE" that is an array of object references
|
|
for zero or more palettes. The Image dataset may have additional attributes
|
|
to describe the image data, as defined in <a href="#Sect1.2">Section 1.2</a>.
|
|
<p>A Palette is an HDF5 dataset which contains color map information.
|
|
A Pallet dataset has an attribute "CLASS=PALETTE" and other attributes
|
|
indicating the type and size of the palette, as defined in <a href="#sect2">Section
|
|
2.1</a>. A Palette is an independent object, which can be shared
|
|
among several Image datasets.
|
|
<h3>
|
|
<a NAME="Sect1.2"></a>1.2 Image Attributes</h3>
|
|
The attributes for the Image are scalars unless otherwise noted.
|
|
The length of String valued attributes should be at least the number of
|
|
characters. Optionally, String valued attributes may be stored in a String
|
|
longer than the minimum, in which case it must be zero terminated or null
|
|
padded. "Required" attributes must always be used. "Optional" attributes
|
|
must be used when required.
|
|
<br>
|
|
<h4>
|
|
Attributes</h4>
|
|
|
|
<dl>
|
|
<dt>
|
|
Attribute name="<b>CLASS</b>" (Required)</dt>
|
|
|
|
<dd>
|
|
This attribute is type H5T_C_S1, with size 5.</dd>
|
|
|
|
<dd>
|
|
For all Images, the value of this attribute is "IMAGE".</dd>
|
|
|
|
<dd>
|
|
</dd>
|
|
|
|
<dd>
|
|
This attribute identifies this data set as intended to be interpreted as
|
|
an image that conforms to the specifications on this page.</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>PALETTE</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
A Image dataset within an HDF5 file may optionally specify an array of
|
|
palettes to be viewed with. The dataset will have an attribute field called
|
|
"<b>PALETTE</b>" which contains a one-dimensional array of object reference
|
|
pointers (HDF5 datatype H5T_STD_REF_OBJ) which refer to palettes in the
|
|
file. The palette datasets must conform to the Palette specification in
|
|
<a href="#sect2">section
|
|
2 below</a>. The first palette in this array will be the default palette
|
|
that the data may be viewed with.</dd>
|
|
</dl>
|
|
|
|
<dl>
|
|
<dt>
|
|
</dt>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_SUBCLASS</b>"</dt>
|
|
|
|
<dd>
|
|
If present, the value of this attribute indicates the type of Palette that
|
|
should be used with the Image. This attribute is a scalar of type
|
|
H5T_C_S1, with size according to the string plus one. The values
|
|
are:</dd>
|
|
|
|
<dl>
|
|
<dt>
|
|
"IMAGE_GRAYSCALE" (length 15)</dt>
|
|
|
|
<dd>
|
|
A grayscale image, values 0-255 indicating brightness.</dd>
|
|
|
|
<dt>
|
|
"IMAGE_BITMAP" (length 12)</dt>
|
|
|
|
<dd>
|
|
A bit map image</dd>
|
|
|
|
<dt>
|
|
"IMAGE_TRUECOLOR" (length 15)</dt>
|
|
|
|
<dd>
|
|
A truecolor image</dd>
|
|
|
|
<dt>
|
|
"IMAGE_INDEXED" (length 13)</dt>
|
|
|
|
<dd>
|
|
An indexed image</dd>
|
|
|
|
<dd>
|
|
</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>INTERLACE_MODE</b>"</dt>
|
|
|
|
<dd>
|
|
For images with more than one component for each pixel, this optional attribute
|
|
specifies the layout of the data. The values are type H5T_C_S1 of length
|
|
15. See <a href="#Section1.3">section 1.3</a> for information about the
|
|
storage layout for data.</dd>
|
|
|
|
<dd>
|
|
"INTERLACE_PIXEL" (default): the component value for a pixel are contiguous.</dd>
|
|
|
|
<dd>
|
|
"INTERLACE_PLANE": each component is stored as a plane.</dd>
|
|
|
|
<dt>
|
|
</dt>
|
|
|
|
<dt>
|
|
Attribute name="<b>DISPLAY_ORIGIN</b>"</dt>
|
|
|
|
<dd>
|
|
This optional attribute indicates the intended orientation of the data
|
|
on a two-dimensional raster display. The value indicates which corner
|
|
the pixel at (0, 0) should be viewed. The values are type H5T_C_S1
|
|
of length 2. If DISPLAY_ORIGIN is not set, the orientation is undefined.</dd>
|
|
|
|
<dd>
|
|
"UL": (0,0) is at the upper left.</dd>
|
|
|
|
<dd>
|
|
"LL": (0,0) is at the lower left.</dd>
|
|
|
|
<dd>
|
|
"UR": (0,0) is at the upper right.</dd>
|
|
|
|
<dd>
|
|
"LR": (0,0) is at the lower right.</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_WHITE_IS_ZERO</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
This attribute is of type H5T_NATIVE_UCHAR. 0 = false, 1 = true .
|
|
This is used for images with IMAGE_SUBCLASS="IMAGE_GRAYSCALE" or "IMAGE_BITMAP".</dd>
|
|
</dl>
|
|
|
|
<dl>
|
|
<dt>
|
|
Attribute name="<b>IMAGE_MINMAXRANGE</b>"</dt>
|
|
|
|
<dd>
|
|
If present, this attribute is an array of two numbers, of the same HDF5
|
|
datatype as the data. The first element is the minimum value of the
|
|
data, and the second is the maximum. This is used for images with
|
|
IMAGE_SUBCLASS="IMAGE_GRAYSCALE", "IMAGE_BITMAP" or "IMAGE_INDEXED".</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_BACKGROUNDINDEX</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
If set, this attribute indicates the index value that should be interpreted
|
|
as the "background color". This attribute is HDF5 type H5T_NATIVE_UINT.</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_TRANSPARENCY</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
If set, this attribute indicates the index value that should be interpreted
|
|
as the "transparent color". This attribute is HDF5 type H5T_NATIVE_UINT.
|
|
This attribute may not be used for IMAGE_SUBCLASS="IMAGE_TRUE_COLOR".</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_ASPECTRATIO</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
If set, this attribute indicates the aspect ratio. This attribute
|
|
is HDF5 type H5T_NATIVE_UINT.</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_COLORMODEL</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
If set, this attribute indicates the color model of Palette that should
|
|
be used with the Image. This attribute is of type H5T_C_S1, with
|
|
size 3, 4, or 5. The value is one of the color models described in
|
|
the Palette specification in <a href="#sect2.2">section 2.2 below</a>.
|
|
This attribute may be used only for IMAGE_SUBCLASS="IMAGE_TRUECOLOR" or
|
|
"IMAGE_INDEXED".</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>IMAGE_GAMMACORRECTION</b>"</dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
If set, this attribute gives the Gamma correction. The attribute
|
|
is type H5T_NATIVE_FLOAT. This attribute may be used only for IMAGE_SUBCLASS="IMAGE_TRUECOLOR"
|
|
or "IMAGE_INDEXED".</dd>
|
|
</dl>
|
|
Attribute name="<b>IMAGE_VERSION</b>" (Required)
|
|
<dl>
|
|
<dd>
|
|
This attribute is of type H5T_C_S1, with size corresponding to the length
|
|
of the version string. This attribute identifies the version number
|
|
of this specification to which it conforms. The current version number
|
|
is "1.2".</dd>
|
|
|
|
<br>
|
|
<p>
|
|
<br>
|
|
<br>
|
|
<center><table BORDER=2 BGCOLOR="#FFFFFF" >
|
|
<caption><b>Table 1. Attributes of an Image Dataset</b></caption>
|
|
|
|
<tr>
|
|
<td><b>Attribute Name</b></td>
|
|
|
|
<td><b>(R = Required</b>
|
|
<br><b>O= Optional)</b></td>
|
|
|
|
<td><b>Type</b></td>
|
|
|
|
<td><b>String Size</b></td>
|
|
|
|
<td><b>Value</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>CLASS</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>5</td>
|
|
|
|
<td>"IMAGE"</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>PALETTE</td>
|
|
|
|
<td>O</td>
|
|
|
|
<td>Array Object References</td>
|
|
|
|
<td></td>
|
|
|
|
<td><references to Palette datasets><sup>1</sup></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_SUBCLASS</td>
|
|
|
|
<td>O<sup>2</sup></td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>15,
|
|
<br>12,
|
|
<br>15,
|
|
<br>13</td>
|
|
|
|
<td>
|
|
<dt>
|
|
"IMAGE_GRAYSCALE",</dt>
|
|
|
|
<dt>
|
|
"IMAGE_BITMAP",</dt>
|
|
|
|
<dt>
|
|
"IMAGE_TRUECOLOR",</dt>
|
|
|
|
<dt>
|
|
"IMAGE_INDEXED"</dt>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>INTERLACE_MODE</td>
|
|
|
|
<td>O<sup>3,6</sup></td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>15</td>
|
|
|
|
<td>The layout of components if more than one component per pixel.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>DISPLAY_ORIGIN</td>
|
|
|
|
<td>O</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>2</td>
|
|
|
|
<td>If set, indicates the intended location of the pixel (0,0).</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_WHITE_IS_ZERO</td>
|
|
|
|
<td>O<sup>3,4</sup></td>
|
|
|
|
<td>Unsigned Integer</td>
|
|
|
|
<td></td>
|
|
|
|
<td>0 = false, 1 = true</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_MINMAXRANGE</td>
|
|
|
|
<td>O<sup>3,5</sup></td>
|
|
|
|
<td>Array [2] <same datatype as data values></td>
|
|
|
|
<td></td>
|
|
|
|
<td>The (<minimum>, <maximum>) value of the data.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_BACKGROUNDINDEX</td>
|
|
|
|
<td>O<sup>3</sup></td>
|
|
|
|
<td>Unsigned Integer</td>
|
|
|
|
<td></td>
|
|
|
|
<td>The index of the background color.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_TRANSPARENCY</td>
|
|
|
|
<td>O<sup>3,5</sup></td>
|
|
|
|
<td>Unsigned Integer</td>
|
|
|
|
<td></td>
|
|
|
|
<td>The index of the transparent color.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_ASPECTRATIO</td>
|
|
|
|
<td>O<sup>3,4</sup></td>
|
|
|
|
<td>Unsigned Integer</td>
|
|
|
|
<td></td>
|
|
|
|
<td>The aspect ratio.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_COLORMODEL</td>
|
|
|
|
<td>O<sup>3,6</sup></td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>3, 4, or 5</td>
|
|
|
|
<td>The color model, as defined below in the Palette specification for
|
|
attribute <b>PAL_COLORMODEL</b>.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_GAMMACORRECTION</td>
|
|
|
|
<td>O<sup>3,6</sup></td>
|
|
|
|
<td>Float</td>
|
|
|
|
<td></td>
|
|
|
|
<td>The gamma correction.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>IMAGE_VERSION</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>3</td>
|
|
|
|
<td>"1.2"</td>
|
|
</tr>
|
|
</table></center>
|
|
|
|
<dl><font size=-1>1. The first element of the array is the default
|
|
Palette.</font>
|
|
<br><font size=-1>2. This attribute is <b>required</b> for images
|
|
that use one of the standard color map types listed.</font>
|
|
<br><font size=-1>3. This attribute is <b>required</b> if set for the source
|
|
image, in the case that the image is translated from another file into
|
|
HDF5.</font>
|
|
<br><font size=-1>4. This applies to: IMAGE_SUBCLASS="IMAGE_GRAYSCALE"
|
|
or "IMAGE_BITMAP".</font>
|
|
<br><font size=-1>5. This applies to: IMAGE_SUBCLASS="IMAGE_GRAYSCALE",
|
|
"IMAGE_BITMAP", or "IMAGE_INDEXED".</font>
|
|
<br><font size=-1>6. This applies to: IMAGE_SUBCLASS="IMAGE_TRUECOLOR",
|
|
or "IMAGE_INDEXED".</font></dl>
|
|
</dl>
|
|
Table 2 summarizes the standard attributes for an Image datasets using
|
|
the common sub-classes. R means that the attribute listed on the leftmost
|
|
column is Required for the image subclass on the first row, O means that
|
|
the attribute is Optional for that subclass and N that the attribute cannot
|
|
be applied to that subclass. The two first rows show the only required
|
|
attributes
|
|
for all subclasses.
|
|
<br>
|
|
<table BORDER WIDTH="100%" >
|
|
<caption><b>Table 2a. Applicability of Attributes to IMAGE sub-classes</b></caption>
|
|
|
|
<tr>
|
|
<td WIDTH="20%"><b>IMAGE_SUBCLASS</b><sup>1</sup></td>
|
|
|
|
<td WIDTH="20%"><b>IMAGE_GRAYSCALE</b></td>
|
|
|
|
<td WIDTH="20%"><b>IMAGE_BITMAP</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">CLASS</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_VERSION</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>INTERLACE_MODE</td>
|
|
|
|
<td>N</td>
|
|
|
|
<td>N</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_WHITE_IS_ZERO</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_MINMAXRANGE</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_BACKGROUNDINDEX</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_TRANSPARENCY</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_ASPECTRATIO</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_COLORMODEL</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_GAMMACORRECTION</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">PALETTE</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>DISPLAY_ORIGIN</td>
|
|
|
|
<td>O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<blockquote> </blockquote>
|
|
|
|
<table BORDER WIDTH="100%" >
|
|
<caption><b>Table 2b. Applicability of Attributes to IMAGE sub-classes</b></caption>
|
|
|
|
<tr>
|
|
<td WIDTH="20%"><b>IMAGE_SUBCLASS</b></td>
|
|
|
|
<td WIDTH="20%"><b>IMAGE_TRUECOLOR</b></td>
|
|
|
|
<td><b>IMAGE_INDEXED</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">CLASS</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
|
|
<td>R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_VERSION</td>
|
|
|
|
<td WIDTH="20%">R</td>
|
|
|
|
<td>R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>INTERLACE_MODE</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>N</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_WHITE_IS_ZERO</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td>N</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_MINMAXRANGE</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_BACKGROUNDINDEX</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_TRANSPARENCY</td>
|
|
|
|
<td WIDTH="20%">N</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_ASPECTRATIO</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_COLORMODEL</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">IMAGE_GAMMACORRECTION</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="20%">PALETTE</td>
|
|
|
|
<td WIDTH="20%">O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>DISPLAY_ORIGIN</td>
|
|
|
|
<td>O</td>
|
|
|
|
<td>O</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<h3>
|
|
<a NAME="Section1.3"></a>1.3 Storage Layout and Properties for Images</h3>
|
|
In the case of an image with more than one component per pixel (e.g., Red,
|
|
Green, and Blue), the data may be arranged in one of two ways. Following
|
|
HDF4 terminology, the data may be interlaced by pixel or by plane, which
|
|
should be indicated by the INTERLACE_MODE attribute. In both
|
|
cases, the dataset will have a dataspace with three dimensions, height,
|
|
width, and components. The interlace modes specify different orders
|
|
for the dimensions.
|
|
<br>
|
|
<table BORDER COLS=2 WIDTH="100%" >
|
|
<caption><b>Table 3. Storage of multiple component image data.</b></caption>
|
|
|
|
<tr>
|
|
<td><b>Interlace Mode</b></td>
|
|
|
|
<td><b>Dimensions in the Dataspace</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>INTERLACE_PIXEL</td>
|
|
|
|
<td>[height][width][pixel components]</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>INTERLACE_PLANE</td>
|
|
|
|
<td>[pixel components][height][width]</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<p>For example, consider a 5 (rows) by 10 (column) image, with Red, Green,
|
|
and Blue components. Each component is an unsigned byte. In HDF5,
|
|
the datatype would be declared as an unsigned 8 bit integer. For
|
|
pixel interlace, the dataspace would be a three dimensional array, with
|
|
dimensions: [10][5][3]. For plane interleave, the dataspace would
|
|
be three dimensions: [3][10][5].
|
|
<p>In the case of images with only one component, the dataspace may be
|
|
either a two dimensional array, or a three dimensional array with the third
|
|
dimension of size 1. For example, a 5 by 10 image with 8 bit color
|
|
indexes would be an HDF5 dataset with type unsigned 8 bit integer.
|
|
The dataspace could be either a two dimensional array, with dimensions
|
|
[10][5], or three dimensions, with dimensions either [10][5][1] or [1][10][5].
|
|
<p>Image datasets may be stored with any chunking or compression properties
|
|
supported by HDF5.
|
|
<p><b>A note concerning compatibility with HDF5 GR interface: </b>An Image
|
|
dataset is stored as an HDF5 dataset. It is important to note that
|
|
the order of the dimensions is the same as for any other HDF5 dataset.
|
|
For a two dimensional image that is to be stored as a series of horizontal
|
|
scan lines, with the scan lines contiguous (i.e., the fastest changing
|
|
dimension is 'width'), the image will have a dataspace with <i>dim[0] =
|
|
height</i> and <i>dim[1]</i> = <i>width</i>. This is completely consistent
|
|
with all other HDF5 datasets.
|
|
<p>Users familiar with HDF4 should be cautioned that <i>this is not the
|
|
same as HDF4</i>, and specifically is not consistent with what the HDF4
|
|
GR interface does.
|
|
<br>
|
|
<h2>
|
|
<a NAME="sect2"></a>2. HDF5 Palette Specification</h2>
|
|
|
|
<h3>
|
|
2.1 Overview</h3>
|
|
A palette is the means by which color is applied to an image and is also
|
|
referred to as a color lookup table. It is a table in which every row contains
|
|
the numerical representation of a particular color. In the example of an
|
|
8 bit standard RGB color model palette, this numerical representation of
|
|
a color is presented as a triplet specifying the intensity of red, green,
|
|
and blue components that make up each color.
|
|
<center>
|
|
<p><img SRC="Palettes.fm.anc.gif" ></center>
|
|
|
|
<p>In this example, the color component numeric type is an 8 bit unsigned
|
|
integer. While this is most common and recommended for general use, other
|
|
component color numeric datatypes, such as a 16 bit unsigned integer ,
|
|
may be used. This type is specified as the type attribute of the palette
|
|
dataset. (see H5Tget_type(), H5Tset_type())
|
|
<p>The minimum and maximum values of the component color numeric are specified
|
|
as attribute of the palette dataset. See below (attribute PAL_MINMAXNUMERIC).
|
|
If these attributes do not exist, it is assumed that the range of values
|
|
will fill the space of the color numeric type. i.e. with an 8 bit unsigned
|
|
integer, the valid range would be 0 to 255 for each color component.
|
|
<p>The HDF5 palette specification additionally allows for color models
|
|
beyond RGB. YUV, HSV, CMY, CMYK, YCbCr color models are supported, and
|
|
may be specified as a color model attribute of the palette dataset. <i>(see
|
|
"Palette Attributes" for details)</i>.
|
|
<p>In HDF 4 and earlier, palettes were limited to 256 colors. The HDF5
|
|
palette specification allows for palettes of varying length. The length
|
|
is specified as the number of rows of the palette dataset.
|
|
<br>
|
|
<br>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#666666" >
|
|
<tr>
|
|
<td><font color="#FFFFFF">Important Note: The specification of the Indexed
|
|
Palette will change substantially in the next version. The Palette
|
|
described here is <i>denigrated</i> and is not supported.</font></td>
|
|
</tr>
|
|
</table>
|
|
|
|
<br>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td><i>Denigrated</i>
|
|
<p>In a standard palette, the color entries are indexed directly. HDF5
|
|
supports the notion of a range index table. Such a table defines an ascending
|
|
ordered list of ranges that map dataset values to the palette. If a range
|
|
index table exists for the palette, the PAL_TYPE attribute will be set
|
|
to "RANGEINDEX", and the PAL_RANGEINDEX attribute will contain an object
|
|
reference to a range index table array. If not, the PAL_TYPE attribute
|
|
either does not exist, or will be set to "STANDARD".
|
|
<p>The range index table array consists of a one dimensional array with
|
|
the same length as the palette dataset - 1. Ideally, the range index would
|
|
be of the same type as the dataset it refers to, however this is not a
|
|
requirement.
|
|
<p><b>Example 2: A range index array of type floating point</b>
|
|
<center>
|
|
<p><img SRC="PaletteExample1.gif" ></center>
|
|
|
|
<p>The range index array attribute defines the "<i>to</i>" of the range.
|
|
Notice that the range index array attribute is one less entry in size than
|
|
the palette. The first entry of 0.1259, specifies that all values below
|
|
and up to 0.1259 inclusive, will map to the first palette entry. The second
|
|
entry signifies that all values greater than 0.1259 up to 0.3278 inclusive,
|
|
will map to the second palette entry, etc. All value greater than the last
|
|
range index array attribute (100000) map to the last entry in the palette.</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<h3>
|
|
<a NAME="sect2.2"></a>2.2. Palette Attributes</h3>
|
|
A palette exists in an HDF file as an independent data set with accompanying
|
|
attributes. The Palette attributes are scalars except where noted
|
|
otherwise. String values should have size the length of the string
|
|
value plus one. "Required" attributes must be used. "Optional"
|
|
attributes must be used when required.
|
|
<p>These attributes are defined as follows:
|
|
<dl>
|
|
<dt>
|
|
Attribute name="<b>CLASS</b>" (Required)</dt>
|
|
|
|
<dd>
|
|
This attribute is of type H5T_C_S1, with size 7.</dd>
|
|
|
|
<dd>
|
|
For all palettes, the value of this attribute is "PALETTE". This attribute
|
|
identifies this palette data set as a palette that conforms to the specifications
|
|
on this page.</dd>
|
|
|
|
<dt>
|
|
Attribute name="<b>PAL_COLORMODEL</b>" (Required)</dt>
|
|
|
|
<dd>
|
|
This attribute is of type H5T_C_S1, with size 3, 4, or 5.</dd>
|
|
|
|
<dd>
|
|
Possible values for this are "RGB", "YUV", "CMY", "CMYK", "YCbCr", "HSV".</dd>
|
|
|
|
<dd>
|
|
This defines the color model that the entries in the palette data set represent.</dd>
|
|
|
|
<dl>
|
|
<dt>
|
|
"RGB"</dt>
|
|
|
|
<dd>
|
|
Each color index contains a triplet where the the first value defines the
|
|
red component, second defines the green component, and the third the blue
|
|
component.</dd>
|
|
|
|
<dt>
|
|
"CMY"</dt>
|
|
|
|
<dd>
|
|
Each color index contains a triplet where the the first value defines the
|
|
cyan component, second defines the magenta component, and the third the
|
|
yellow component.</dd>
|
|
|
|
<dt>
|
|
"CMYK"</dt>
|
|
|
|
<dd>
|
|
Each color index contains a quadruplet where the the first value defines
|
|
the cyan component, second defines the magenta component, the third the
|
|
yellow component, and the forth the black component.</dd>
|
|
|
|
<dt>
|
|
"YCbCr"</dt>
|
|
|
|
<dd>
|
|
Class Y encoding model. Each color index contains a triplet where the the
|
|
first value defines the luminance, second defines the Cb Chromonance, and
|
|
the third the Cr Chromonance.</dd>
|
|
|
|
<dt>
|
|
"YUV"</dt>
|
|
|
|
<dd>
|
|
Composite encoding color model. Each color index contains a triplet where
|
|
the the first value defines the luminance component, second defines the
|
|
chromonance component, and the third the value component.</dd>
|
|
|
|
<dt>
|
|
"HSV"</dt>
|
|
|
|
<dd>
|
|
Each color index contains a triplet where the the first value defines the
|
|
hue component, second defines the saturation component, and the third the
|
|
value component. The hue component defines the hue spectrum with a low
|
|
value representing magenta/red progressing to a high value which would
|
|
represent blue/magenta, passing through yellow, green, cyan. A low value
|
|
for the saturation component means less color saturation than a high value.
|
|
A low value for <i>value</i> will be darker than a high value.</dd>
|
|
|
|
<dd>
|
|
</dd>
|
|
</dl>
|
|
|
|
<dt>
|
|
Attribute name="<b>PAL_TYPE</b>" (Required)</dt>
|
|
|
|
<dd>
|
|
This attribute is of type H5T_C_S1, with size 9 or 10.</dd>
|
|
|
|
<dd>
|
|
The current supported values for this attribute are : "STANDARD8" or "RANGEINDEX"</dd>
|
|
|
|
<dd>
|
|
A PAL_TYPE of "STANDARD8" defines a palette dataset such that the first
|
|
entry defines index 0, the second entry defines index 1, etc. up until
|
|
the length of the palette - 1. This assumes an image dataset with direct
|
|
indexes into the palette.</dd>
|
|
</dl>
|
|
|
|
<dl>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td><i>Denigrated</i>
|
|
<p>If the PAL_TYPE is set to "RANGEINDEX", there will be an additional
|
|
attribute with a name of "<b>PAL_RANGEINDEX</b>", (See example 2
|
|
for more details)</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td>
|
|
<dt>
|
|
Attribute name="<b>PAL_RANGEINDEX</b>" <i>(Denigrated)</i></dt>
|
|
|
|
<dl>
|
|
<dd>
|
|
The <b>PAL_RANGEINDEX</b> attribute contains an HDF object reference (HDF5
|
|
datatype H5T_STD_REF_OBJ) pointer which specifies a range index array in
|
|
the file to be used for color lookups for the palette. (Only for
|
|
PAL_TYPE="RANGEINDEX")</dd>
|
|
</dl>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<dt>
|
|
Attribute name="<b>PAL_MINMAXNUMERIC</b>"</dt>
|
|
|
|
<dl>
|
|
<dt>
|
|
If present, this attribute is an array of two numbers, of the same HDF5
|
|
datatype as the palette elements or color numerics.</dt>
|
|
|
|
<br>They specify the minimum and maximum values of the color numeric components.
|
|
For example, if the palette was an RGB of type Float, the color numeric
|
|
range for Red, Green, and Blue could be set to be between 0.0 and 1.0.
|
|
The intensity of the color guns would then be scaled accordingly to be
|
|
between this minimum and maximum attribute.</dl>
|
|
Attribute name="<b>PAL_VERSION</b>" (Required)
|
|
<dl>This attribute is of type H5T_C_S1, with size corresponding to the
|
|
length of the version string. This attribute identifies the version
|
|
number of this specification to which it conforms. The current version
|
|
is "1.2".</dl>
|
|
|
|
<center><table BORDER=2 BGCOLOR="#FFFFFF" >
|
|
<caption><b>Table 4. Attributes of a Palette Dataset</b></caption>
|
|
|
|
<tr>
|
|
<td><b>Attribute Name</b></td>
|
|
|
|
<td><b>(R = Required,</b>
|
|
<br><b>O = Optional)</b></td>
|
|
|
|
<td><b>Type</b></td>
|
|
|
|
<td><b>String Size</b></td>
|
|
|
|
<td><b>Value</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>CLASS</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>
|
|
<center>7</center>
|
|
</td>
|
|
|
|
<td>"PALETTE"</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>PAL_COLORMODEL</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>
|
|
<center>3, 4, or 5</center>
|
|
</td>
|
|
|
|
<td>Color Model: "RGB", YUV", "CMY", "CMYK", "YCbCr", or "HSV"</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>PAL_TYPE</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>
|
|
<center>9</center>
|
|
|
|
<p><br>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td>or 10</td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
|
|
<td>"STANDARD8"
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td>or "RANGEINDEX" <i>(Denigrated)</i></td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td><i>Denigrated</i>
|
|
<br>RANGE_INDEX</td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
|
|
<td></td>
|
|
|
|
<td>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td>Object Reference </td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
|
|
<td></td>
|
|
|
|
<td>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td><Object Reference to Dataset of range index values></td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>PAL_MINMAXNUMERIC</td>
|
|
|
|
<td>O</td>
|
|
|
|
<td>Array[2] of <same datatype as palette></td>
|
|
|
|
<td></td>
|
|
|
|
<td>The first value is the <Minimum value for color values>, the second
|
|
value is <Maximum value for color values><sup>2</sup></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>PAL_VERSION</td>
|
|
|
|
<td>R</td>
|
|
|
|
<td>String</td>
|
|
|
|
<td>4</td>
|
|
|
|
<td>"1.2"</td>
|
|
</tr>
|
|
</table></center>
|
|
|
|
<dl>
|
|
<table BORDER COLS=1 WIDTH="100%" BGCOLOR="#CCCCCC" >
|
|
<tr>
|
|
<td><font size=-1>1. The RANGE_INDEX attribute is required if the
|
|
PAL_TYPE is "RANGEINDEX". Otherwise, the RANGE_INDEX attribute should
|
|
be omitted. (Range index is denigrated.)</font></td>
|
|
</tr>
|
|
</table>
|
|
<font size=-1>2. The minimum and maximum are optional. If not
|
|
set, the range is assumed to the maximum range of the number type.
|
|
If one of these attributes is set, then both should be set. The value
|
|
of the minimum must be less than or equal to the value of the maximum.</font></dl>
|
|
</dl>
|
|
Table 5 summarized the uses of the standard attributes for a palette dataset.
|
|
R means that the attribute listed on the leftmost column is Required for
|
|
the palette type on the first row, O means that the attribute is Optional
|
|
for that type and N that the attribute cannot be applied to that type.
|
|
The four first rows show the attributes that are always required
|
|
for the two palette types.
|
|
<br>
|
|
<br>
|
|
<table BORDER WIDTH="100%" >
|
|
<caption><b>Table 5. Applicability of Attributes</b></caption>
|
|
|
|
<tr>
|
|
<td WIDTH="33%"><b>PAL_TYPE</b></td>
|
|
|
|
<td WIDTH="33%"><b>STANDARD8</b></td>
|
|
|
|
<td WIDTH="34%"><b>RANGEINDEX</b></td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="33%">CLASS</td>
|
|
|
|
<td WIDTH="33%">R</td>
|
|
|
|
<td WIDTH="34%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="33%">PAL_VERSION</td>
|
|
|
|
<td WIDTH="33%">R</td>
|
|
|
|
<td WIDTH="34%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="33%">PAL_COLORMODEL</td>
|
|
|
|
<td WIDTH="33%">R</td>
|
|
|
|
<td WIDTH="34%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="33%">RANGE_INDEX</td>
|
|
|
|
<td WIDTH="33%">N</td>
|
|
|
|
<td WIDTH="34%">R</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td WIDTH="33%">PAL_MINMAXNUMERIC</td>
|
|
|
|
<td WIDTH="33%">O</td>
|
|
|
|
<td WIDTH="34%">O</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<h3>
|
|
2.3. Storage Layout for Palettes</h3>
|
|
The values of the Palette are stored as a dataset. The datatype can
|
|
be any HDF 5 atomic numeric type. The dataset will have dimensions
|
|
(<tt>nentries</tt> by <tt>ncomponents</tt>), where '<tt>nentries</tt>'
|
|
is the number of colors (usually 256) and '<tt>ncomponents'</tt> is the
|
|
number of values per color (3 for <b>RGB</b>, 4 for <b>CMYK</b>, etc.)
|
|
<br>
|
|
<h2>
|
|
<a NAME="Sect3"></a>3. Consistency and Correlation of Image and Palette
|
|
Attributes</h2>
|
|
The objects in this specification are an extension to the base HDF5 specification
|
|
and library. They are accessible with the standard HDF5 library,
|
|
but the semantics of the objects are not enforced by the base library.
|
|
For example, it is perfectly possible to add an attribute called <b>IMAGE</b>
|
|
to <i>any</i> dataset, or to include an object reference to <i>any</i>
|
|
HDF5 dataset in a <b>PALETTE</b> attribute. This would be a valid
|
|
HDF5 file, but not conformant to this specification. The rules defined
|
|
in this specification must be implemented with appropriate software, and
|
|
applications must use conforming software to assure correctness.
|
|
<p>The Image and Palette specifications include several redundant standard
|
|
attributes, such as the <b>IMAGE_COLORMODEL</b> and the <b>PAL_COLORMODEL</b>.
|
|
These attributes are informative not normative, in that it is acceptable
|
|
to attach a Palette to an Image dataset even if their attributes do not
|
|
match. Software is not required to enforce consistency, and files
|
|
may contain mismatched associations of Images and Palettes. In all
|
|
cases, it is up to applications to determine what kinds of images and color
|
|
models can be supported.
|
|
<p>For example, an Image that was created from a file with an "RGB" may
|
|
have a "YUV" Palette in its <b>PALETTE</b> attribute array. This
|
|
would be a legal HDF5 file and also conforms to this specification, although
|
|
it may or may not be correct for a given application.</p>
|
|
|
|
|
|
<!-- #BeginLibraryItem "/ed_libs/NavBar_ADevG.lbi" --><hr>
|
|
<center>
|
|
<table border=0 width=98%>
|
|
<tr><td valign=top align=left>
|
|
<a href="../index.html">HDF5 documents and links</a> <br>
|
|
<a href="../H5.intro.html">Introduction to HDF5</a> <br>
|
|
<!--
|
|
<a href="Glossary.html">Glossary</a><br>
|
|
-->
|
|
</td>
|
|
<td valign=top align=right>
|
|
<a href="http://hdf.ncsa.uiuc.edu/HDF5/doc/UG/index.html">HDF5 User's Guide</a> <br>
|
|
<a href="../RM_H5Front.html">HDF5 Reference Manual</a> <br>
|
|
<a href="../ADGuide.html">HDF5 Application Developer's Guide</a> <br>
|
|
</td></tr>
|
|
</table>
|
|
</center>
|
|
<hr>
|
|
<!-- #EndLibraryItem --><!-- #BeginLibraryItem "/ed_libs/Footer.lbi" --><address>
|
|
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
|
|
<br>
|
|
Describes HDF5 Release 1.6.0, July 2003
|
|
</address><!-- #EndLibraryItem --><!-- Created: Spring 1999 -->
|
|
<!-- hhmts start -->
|
|
Last modified: 3 July 2001
|
|
<!-- hhmts end -->
|
|
|
|
</body>
|
|
</html>
|