<version>$Revision$</version>
</header>
<body>
+ <section id="introduction">
+ <title>Introduction</title>
+ <p>
+ After the Apache FOP 0.94 release, the image handling subsystem has been rewritten in
+ order to improve the range of supported images and image subtypes, to lower the
+ overall memory consumption when handling images, to produce smaller output files and to
+ increase the performance in certain areas. Of course, this causes a few changes most of
+ which the user will probably not notice. The most important changes are:
+ </p>
+ <ul>
+ <li>
+ The image libraries Jimi and JAI are no longer supported. Instead, Apache FOP uses the
+ Image I/O API that was introduced with Java 1.4 for all bitmap codecs.
+ </li>
+ <li>
+ Some bitmap images are no longer converted to a standardized 24 bit RGB image but are
+ instead handled in their native format.
+ </li>
+ <li>
+ A plug-in mechanism offers a possibility to add support for new formats without changing
+ the FOP's source code.
+ </li>
+ </ul>
+ <p>
+ The actual <a href="http://xmlgraphics.apache.org/commons/image-loader.html">image loading framework</a>
+ no longer resides in Apache FOP, but was instead placed in
+ <a href="ext:xmlgraphics.apache.org/commons/">XML Graphics Commons</a>.
+ </p>
+ </section>
<section id="support-overview">
<title>Overview of Graphics Support</title>
<p>
- The table below summarizes the <em>theoretical</em> support for graphical formats within FOP. In other words, within the constraints of the limitations listed here, these formats <em>should</em> work. However, many of them have not been tested, and there may be limitations that have not yet been discovered or documented. The packages needed to support some formats are not included in the FOP distribution and must be installed separately. Follow the links in the "Support Thru" column for more details.
+ The table below summarizes the <em>theoretical</em> support for graphical formats
+ within FOP. In other words, within the constraints of the limitations listed here,
+ these formats <em>should</em> work. However, many of them have not been tested,
+ and there may be limitations that have not yet been discovered or documented.
+ The packages needed to support some formats are not included in the FOP distribution
+ and must be installed separately. Follow the links in the "Support Through" columns
+ for more details.
</p>
<table>
<tr>
- <th>Format</th>
- <th>Type</th>
- <th><a href="#native">FOP native support</a></th>
- <th><a href="#batik">Batik SVG</a></th>
- <th><a href="#batik-codecs">Batik codecs</a></th>
+ <th rowspan="2">Format</th>
+ <th rowspan="2">Type</th>
+ <th colspan="3">Support Through</th>
+ </tr>
+ <tr>
+ <th><a href="#native">Apache FOP (native)</a></th>
+ <th><a href="#batik">Apache Batik</a></th>
<th><a href="#imageio">Image I/O</a></th>
- <th><a href="#jai">JAI</a></th>
- <th><a href="#jimi">JIMI</a></th>
</tr>
<tr>
<td><a href="#bmp">BMP</a> (Microsoft Windows Bitmap)</td>
<td>bitmap</td>
- <td>X</td>
- <td></td>
<td></td>
<td></td>
+ <td>X [1]</td>
+ </tr>
+ <tr>
+ <td><a href="#emf">EMF</a> (Windows Enhanced Metafile)</td>
+ <td>vector (with embedded bitmaps)</td>
+ <td>(X)</td>
<td></td>
<td></td>
</tr>
<tr>
<td><a href="#eps">EPS</a> (Encapsulated PostScript)</td>
- <td>metafile (both bitmap and vector), probably most frequently used for vector drawings</td>
+ <td>metafile (both bitmap and vector), most frequently used for vector drawings</td>
<td>(X)</td>
<td></td>
<td></td>
- <td></td>
- <td></td>
- <td></td>
</tr>
<tr>
<td>GIF (Graphics Interchange Format)</td>
<td>bitmap</td>
- <td>X</td>
<td></td>
<td></td>
<td>X</td>
- <td>X</td>
- <td>X</td>
</tr>
<tr>
<td><a href="#jpeg">JPEG</a> (Joint Photographic Experts Group)</td>
<td>bitmap</td>
<td>(X)</td>
<td></td>
- <td></td>
<td>X</td>
- <td></td>
- <td></td>
</tr>
<tr>
<td><a href="#png">PNG</a> (Portable Network Graphic)</td>
<td></td>
<td></td>
<td>X</td>
- <td>X</td>
- <td></td>
- <td></td>
</tr>
<tr>
<td><a href="#svg">SVG</a> (Scalable Vector Graphics)</td>
<td></td>
<td>X</td>
<td></td>
- <td></td>
- <td></td>
- <td></td>
</tr>
<tr>
<td><a href="#tiff">TIFF</a> (Tag Image Format File)</td>
<td>bitmap</td>
<td>(X)</td>
<td></td>
- <td>X</td>
- <td>X</td>
- <td>X</td>
- <td></td>
- <!--td><a href="#native">FOP native</a> or <a href="#jai">JAI</a>, depending on the subformat. See <a href="#tiff">TIFF</a> for more details.(JIMI also supports TIFF, but this has not been implemented within FOP).</td-->
+ <td>X [1]</td>
</tr>
<tr>
- <td><a href="#emf">EMF</a> (Windows Enhanced Metafile)</td>
+ <td><a href="#wmf">WMF</a> (Windows Metafile)</td>
<td>vector (with embedded bitmaps)</td>
- <td>(X)</td>
- <td></td>
- <td></td>
- <td></td>
<td></td>
+ <td>(X)</td>
<td></td>
</tr>
</table>
- <note>"(X)" means restricted support. Please see the details below.</note>
+ <p>
+ Legend:
+ </p>
+ <ul>
+ <li>"(X)" means restricted support. Please see the details below.</li>
+ <li>
+ [1]: Requires the presence of <a href="http://jai-imageio.dev.java.net/">JAI Image I/O Tools</a>
+ (or an equivalent Image I/O compatible codec) in the classpath. JAI Image I/O Tools also
+ adds support for JPEG 2000, WBMP, RAW and PNM. Other Image I/O codecs may provide
+ support for additional formats.
+ </li>
+ </ul>
+ <section id="format-map">
+ <title>Map of supported image formats by output format</title>
+ <p>
+ Not all image formats are supported for all output formats! For example, while you can
+ use EPS (Encapsulated PostScript) files when you generate PostScript output, this format
+ will not be supported by any other output format. Here's an overview which image formats
+ are supported by which output format:
+ </p>
+ <table>
+ <tr>
+ <th>Image Format</th>
+ <th>PDF</th>
+ <th>PostScript</th>
+ <th>Java2D, PNG, TIFF, AWT</th>
+ <th>PCL</th>
+ <th>AFP</th>
+ <th>RTF</th>
+ </tr>
+ <tr>
+ <td><a href="#bmp">BMP</a> (Microsoft Windows Bitmap)</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#emf">EMF</a> (Windows Enhanced Metafile)</td>
+ <td></td>
+ <td></td>
+ <td></td>
+ <td></td>
+ <td></td>
+ <td>X [1]</td>
+ </tr>
+ <tr>
+ <td><a href="#eps">EPS</a> (Encapsulated PostScript)</td>
+ <td></td>
+ <td>X [1]</td>
+ <td></td>
+ <td></td>
+ <td></td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>GIF (Graphics Interchange Format)</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#jpeg">JPEG</a> (Joint Photographic Experts Group)</td>
+ <td>X [1]</td>
+ <td>X [1]</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X [1]</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#png">PNG</a> (Portable Network Graphic)</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#svg">SVG</a> (Scalable Vector Graphics)</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#tiff">TIFF</a> (Tag Image Format File)</td>
+ <td>X [2]</td>
+ <td>X [2]</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X [2]</td>
+ <td>X</td>
+ </tr>
+ <tr>
+ <td><a href="#wmf">WMF</a> (Windows Metafile)</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ <td>X</td>
+ </tr>
+ </table>
+ <p>
+ Legend:
+ </p>
+ <ul>
+ <li>
+ [1]: Supported without the need to decode the image.
+ </li>
+ <li>
+ [2]: Supported without the need to decode the image, but only for certain subtypes.
+ </li>
+ </ul>
+ </section>
</section>
<section id="packages">
<title>Graphics Packages</title>
<section id="native">
- <title>FOP Native</title>
+ <title>XML Graphics Commons Native</title>
<p>
- FOP has native ability to handle some graphic file formats.
+ <a href="ext:xmlgraphics.apache.org/commons">XML Graphics Commons</a> supports a number
+ graphic file formats natively as basic functionality: all bitmap formats for which there
+ are Image I/O codecs available (JPEG, PNG, GIF, TIFF, etc.), EPS and EMF.
</p>
</section>
- <section id="batik-codecs">
- <title>"Internal" codecs</title>
+ <section id="fop-native">
+ <title>FOP Native</title>
<p>
- Apache XML Graphics Commons contains codecs for PNG and TIFF access. FOP can use these.
+ FOP has no native image plug-ins for the image loading framework of its own but currently
+ hosts the Batik-dependent SVG and WMF plug-ins until they can be moved to
+ <a href="ext:xmlgraphics.apache.org/batik">Apache Batik</a>.
</p>
</section>
- <section id="imageio">
- <title>Image I/O (JDK 1.4 or higher)</title>
+ <section id="batik">
+ <title>Apache Batik</title>
<p>
- For JDKs 1.4 or higher, FOP provides a wrapper to load images through the
- <a class="fork" href="http://java.sun.com/j2se/1.4.2/docs/guide/imageio/index.html">JDK's Image I/O API</a> (JSR 015).
- Image I/O allows to dynamically add additional image codecs. An example of such an add-on library are the
- <a class="fork" href="http://java.sun.com/products/java-media/jai/">JAI Image I/O Tools</a> available from Sun.
+ <a href="ext:xmlgraphics.apache.org/batik">Apache Batik</a> will later receive the
+ SVG and WMF plug-ins for the image loading framework that are currently hosted inside
+ FOP.
</p>
- </section>
- <section id="jimi">
- <title>JIMI</title>
<p>
- Because of licensing issues, the JIMI image library is not included in the FOP distribution. First, <a class="fork" href="http://java.sun.com/products/jimi">download</a> and install it.
-Then, copy the file "JimiProClasses.zip" from the archive to {fop-install-dir}/lib/jimi-1.0.jar. Please note that FOP binary distributions are compiled with JIMI support, so there is no need for you to build FOP to add the support. If jimi-1.0.jar is installed in the right place, it will automatically be used by FOP, otherwise it will not.
+ Current FOP distributions include a distribution of the
+ <a class="fork" href="ext:xmlgraphics.apache.org/batik">Apache Batik</a>.
+ Because Batik's API changes frequently, it is highly recommended that you use the
+ version that ships with FOP, at least when running FOP.
</p>
- </section>
- <section id="jai">
- <title>JAI (Java Advanced Imaging API)</title>
+ <warning>Batik must be run in a graphical environment.</warning>
<p>
- FOP has been compiled with JAI support, but JAI is not included in the FOP distribution.
-To use it, install <a href="http://java.sun.com/products/java-media/jai">JAI</a>, then copy the jai_core.jar and the jai_codec.jar files to {fop-install-dir}/lib.
-JAI is much faster than JIMI, but is not available for all platforms. See <a href="http://java.sun.com/products/java-media/jai/forDevelopers/jaifaq.html#platforms">What platforms are supported?</a> on the JAI FAQ page for more details.
+ Batik must be run in a graphical environment.
+ It uses AWT classes for rendering SVG, which in turn require an X server on Unixish
+ systems. If you run a server without X, or if you can't connect to the X server due to
+ security restrictions or policies (a so-called "headless" environment), SVG rendering
+ will fail.
</p>
- </section>
- <section id="batik">
- <title>Apache Batik</title>
- <p>Current FOP distributions include a distribution of the Apache <a class="fork" href="ext:batik">Batik</a> version 1.6.
-It is automatically installed with FOP.
-Because Batik's API changes frequently, it is highly recommended that you use the version that ships with FOP, at least when running FOP.</p>
- <warning>Batik must be run in a graphical environment.</warning>
- <p>Batik must be run in a graphical environment.
-It uses AWT classes for rendering SVG, which in turn require an X server on Unixish systems.
-If you run a server without X, or if you can't connect to the X server due to security restrictions or policies (a so-called "headless" environment), SVG rendering will fail.</p>
<p>Here are some workarounds:</p>
<ul>
- <li>If you are using JDK 1.4, start it with the <code>-Djava.awt.headless=true</code> command line option.</li>
- <li>Install an X server which provides an in-memory framebuffer without actually using a screen device or any display hardware. One example is Xvfb.</li>
- <li>Install a toolkit which emulates AWT without the need for an underlying X server. One example is the <a href="http://www.eteks.com/pja/en">PJA toolkit</a>, which is free and comes with detailed installation instructions.</li>
+ <li>
+ If you are using JDK 1.4, start it with the <code>-Djava.awt.headless=true</code>
+ command line option.
+ </li>
+ <li>
+ Install an X server which provides an in-memory framebuffer without actually using a
+ screen device or any display hardware. One example is Xvfb.
+ </li>
+ <li>
+ Install a toolkit which emulates AWT without the need for an underlying X server. One
+ example is the <a href="http://www.eteks.com/pja/en">PJA toolkit</a>, which is free
+ and comes with detailed installation instructions.
+ </li>
</ul>
</section>
</section>
- <section id="bmp">
- <title>BMP</title>
- <p>FOP native support for BMP images is limited to the RGB color-space.</p>
- </section>
- <section id="eps">
- <title>EPS</title>
- <p>FOP provides support for two output targets:</p>
- <ul>
- <li>PostScript (full support).</li>
- <li>
- PDF (partial support). Due to the lack of a built-in PostScript interpreter, FOP
- can only embed the EPS file into the PDF. Acrobat Reader will not currently display
- the EPS (it doesn't have a PostScript interpreter, either) but it will be shown
- correctly when you print the PDF on a PostScript-capable printer. PostScript devices
- (including GhostScript) will render the EPS correctly.
- </li>
- </ul>
- <warning>
- Please note that the EPS embedding feature has been <strong>deprecated</strong> in the
- PDF specification version 1.4. You should not use this feature anymore, especially
- since newer PDF tools don't support embedded EPS files anymore.
- </warning>
- <p>
- Other output targets can't be supported at the moment because
- FOP lacks a PostScript interpreter. Furthermore, FOP is not able
- to parse the preview bitmaps sometimes contained in EPS files.
- </p>
- </section>
- <section id="jpeg">
- <title>JPEG</title>
- <p>
- FOP native support of JPEG does not include all variants, especially those containing
- unusual color lookup tables and color profiles.
- If you have trouble with a JPEG image in FOP, try opening it with an image processing
- program (such as Photoshop or Gimp) and then saving it. Specifying 24-bit color output
- may also help. For the PDF and PostScript renderers most JPEG images can be passed
- through without decompression. User reports indicate that grayscale, RGB, and
- CMYK color-spaces are all rendered properly.
- </p>
- </section>
- <section id="png">
- <title>PNG</title>
- <p>
- If using JAI for PNG support, only RGB and RGBA color-spaces are supported for
- FOP rendering.
- </p>
- <p>
- Transparency is supported but not guaranteed to work with every output format.
- </p>
- </section>
- <section id="svg">
- <title>SVG</title>
- <section id="svg-intro">
- <title>Introduction</title>
- <p>FOP uses <a href="#batik"> Apache Batik</a> for SVG support.
-This format can be handled as an <code>fo:instream-foreign-object</code> or in a separate
-file referenced with <code>fo:external-graphic</code>.</p>
- <note>
-Batik's SVG Rasterizer utility may also be used to convert standalone SVG
-documents into PDF. For more information please see the
-<a href="http://xmlgraphics.apache.org/batik/svgrasterizer.html">SVG Rasterizer documentation</a>
-on the Batik site.
- </note>
+ <section id="image-formats">
+ <title>Details on image formats</title>
+ <section id="bmp">
+ <title>BMP</title>
+ <p>
+ BMP images are supported through an Image I/O codec. There may be limitations of the
+ codec which are outside the control of Apache FOP.
+ </p>
</section>
- <section id="svg-pdf-graphics">
- <title>Placing SVG Graphics into PDF</title>
+ <section id="emf">
+ <title>EMF</title>
<p>
-The SVG is rendered into PDF by using PDF commands to draw and fill
-lines and curves. This means that the graphical objects created with
-this remain as vector graphics. The same applies to PostScript output.
-For other output formats the SVG graphic will be converted to a bitmap
-image.
+ Windows Enhanced Metafiles (EMF) are only supported in RTF output where they are
+ embedded without decoding.
</p>
+ </section>
+ <section id="eps">
+ <title>EPS</title>
+ <p>Apache FOP allows to use EPS files when generating PostScript output only.</p>
<p>
-There are a number of SVG things that cannot be converted directly into
-PDF. Parts of the graphic such as effects, patterns and images are inserted
-into the PDF as a raster graphic. The resolution of these raster images can
- be controlled through the "target resolution" setting in the
- <a href="configuration.html">configuration</a>.</p>
+ Other output targets can't be supported at the moment because
+ FOP lacks a PostScript interpreter. Furthermore, FOP is currently not able
+ to parse the preview bitmaps sometimes contained in EPS files.
+ </p>
+ </section>
+ <section id="gif">
+ <title>GIF</title>
<p>
-Currently transparency is limited in PDF so many svg images that
-contain effects or graphics with transparent areas may not be displayed
-correctly.
+ GIF images are supported through an Image I/O codec. Transparency is supported but
+ not guaranteed to work with every output format.
</p>
</section>
- <section id="svg-pdf-text">
- <title>Placing SVG Text into PDF and PostScript</title>
- <p>If possible, Batik will use normal PDF or PostScript text when inserting text. It does
-this by checking if the text can be drawn normally and the font is
-supported. This example svg <a href="../dev/svg/text.svg">text.svg</a> /
-<!--link href="../dev/svg/text.pdf"-->text.pdf<!--/link-->
-shows how various types and effects with text are handled.
-Note that tspan and outlined text are not yet implemented.</p>
+ <section id="jpeg">
+ <title>JPEG</title>
<p>
-Otherwise, text is converted and drawn as a set of shapes by Batik, using the stroking text painter.
-This means that a typical character will
-have about 10 curves (each curve consists of at least 20 characters).
-This can make the output files large and when it is viewed the
-viewer may not normally draw those fine curves very well (In Adobe Acrobat, turning on
-"Smooth Line Art" in the preferences will fix this).
-If the text is inserted into the output file using the inbuilt text commands
-it will use a single character.
+ FOP native support (i.e. the handling of undecoded images) of JPEG does not include all
+ variants, especially those containing unusual color lookup tables and color profiles.
+ If you have trouble with a JPEG image in FOP, try opening it with an image processing
+ program (such as Photoshop or Gimp) and then saving it. Specifying 24-bit color output
+ may also help. For the PDF and PostScript renderers most JPEG images can be passed
+ through without decompression. User reports indicate that grayscale, RGB, and
+ CMYK color spaces are all rendered properly. However, for other output formats, the
+ JPEG images have to be decompressed. Tests have shown that there are some limitation
+ in some Image I/O codecs concerning images in the CMYK color space. Work-arounds are
+ in place but may not always work as expected.
</p>
+ </section>
+ <section id="png">
+ <title>PNG</title>
<p>
- Note that because SVG text can be rendered as either text or a vector graphic, you
- may need to consider settings in your viewer for both. The Acrobat viewer has both
- "smooth line art" and "smooth text" settings that may need to be set for SVG images
- to be displayed nicely on your screen (see Edit / Preferences / Display).
- This setting will not affect the printing of your document, which should be OK in
- any case, but will only affect the quality of the screen display.</p>
+ PNG images are supported through an Image I/O codec. Transparency is supported but
+ not guaranteed to work with every output format.
+ </p>
</section>
- <section id="svg-scaling">
- <title>Scaling</title>
+ <section id="svg">
+ <title>SVG</title>
+ <section id="svg-intro">
+ <title>Introduction</title>
+ <p>FOP uses <a href="#batik"> Apache Batik</a> for SVG support.
+ This format can be handled as an <code>fo:instream-foreign-object</code> or in a separate
+ file referenced with <code>fo:external-graphic</code>.</p>
+ <note>
+ Batik's SVG Rasterizer utility may also be used to convert standalone SVG
+ documents into PDF. For more information please see the
+ <a href="http://xmlgraphics.apache.org/batik/svgrasterizer.html">SVG Rasterizer documentation</a>
+ on the Batik site.
+ </note>
+ </section>
+ <section id="svg-pdf-graphics">
+ <title>Placing SVG Graphics into PDF</title>
+ <p>
+ The SVG is rendered into PDF by using PDF commands to draw and fill
+ lines and curves. This means that the graphical objects created with
+ this remain as vector graphics. The same applies to PostScript output.
+ For other output formats the SVG graphic may be converted to a bitmap
+ image.
+ </p>
+ <p>
+ There are a number of SVG things that cannot be converted directly into
+ PDF. Parts of the graphic such as effects, patterns and images are inserted
+ into the PDF as a raster graphic. The resolution of these raster images can
+ be controlled through the "target resolution" setting in the
+ <a href="configuration.html">configuration</a>.</p>
+ <p>
+ Currently transparency is limited in PDF so many SVG images that
+ contain effects or graphics with transparent areas may not be displayed
+ correctly.
+ </p>
+ </section>
+ <section id="svg-pdf-text">
+ <title>Placing SVG Text into PDF and PostScript</title>
+ <p>If possible, Batik will use normal PDF or PostScript text when inserting text. It does
+ this by checking if the text can be drawn normally and the font is
+ supported. This example svg <a href="../dev/svg/text.svg">text.svg</a> /
+ <!--link href="../dev/svg/text.pdf"-->text.pdf<!--/link-->
+ shows how various types and effects with text are handled.
+ Note that tspan and outlined text are not yet implemented.</p>
+ <p>
+ Otherwise, text is converted and drawn as a set of shapes by Batik, using the
+ stroking text painter. This means that a typical character will
+ have about 10 curves (each curve consists of at least 20 characters).
+ This can make the output files large and when it is viewed the
+ viewer may not normally draw those fine curves very well (In Adobe Acrobat, turning on
+ "Smooth Line Art" in the preferences will fix this). Copy/paste functionality
+ will not be supported in this case.
+ If the text is inserted into the output file using the inbuilt text commands
+ it will use a single character.
+ </p>
+ <p>
+ Note that because SVG text can be rendered as either text or a vector graphic, you
+ may need to consider settings in your viewer for both. The Acrobat viewer has both
+ "smooth line art" and "smooth text" settings that may need to be set for SVG images
+ to be displayed nicely on your screen (see Edit / Preferences / Display).
+ This setting will not affect the printing of your document, which should be OK in
+ any case, but will only affect the quality of the screen display.</p>
+ </section>
+ <section id="svg-scaling">
+ <title>Scaling</title>
+ <p>
+ Currently, SVG images are rendered with the dimensions specified <em>in the SVG
+ file</em>, within the viewport specified in the fo:external-graphic element.
+ For everything to work properly, the two should be equal. The SVG standard leaves
+ this issue as an implementation detail. Additional scaling options are available
+ through XSL-FO means.
+ </p>
+ <p>
+ If you use pixels to specify the size of an SVG graphic the "source resolution" setting
+ in the <a href="configuration.html">configuration</a> will be used to determine the
+ size of a pixel. The use of pixels to specify sizes is discouraged as they may
+ be interpreted differently in different environments.
+ </p>
+ </section>
+ <section id="svg-problems">
+ <title>Known Problems</title>
+ <ul>
+ <li>
+ Soft mask transparency is combined with white so that it looks better
+ on PDF 1.3 viewers but this causes the soft mask to be slightly lighter
+ or darker on PDF 1.4 viewers.
+ </li>
+ <li>
+ There is some problem with a gradient inside a pattern which may cause a PDF
+ error when viewed in Acrobat 5.
+ </li>
+ <li>
+ Text is not always handled correctly, it may select the wrong font
+ especially if characters have multiple fonts in the font list.
+ </li>
+ <li>
+ Uniform transparency for images and other SVG elements that are converted
+ into a raster graphic are not drawn properly in PDF. The image is opaque.
+ </li>
+ </ul>
+ </section>
+ </section>
+ <section id="tiff">
+ <title>TIFF</title>
<p>
- Currently, SVG images are rendered with the dimensions specified <em>in the SVG
- file</em>, within the viewport specified in the fo:external-graphic element.
- For everything to work properly, the two should be equal. The SVG standard leaves
- this issue as an implementation detail. FOP will probably implement a scaling
- mechanism in the future.
+ FOP can embed TIFF images without decompression into PDF, PostScript and AFP if they
+ have either CCITT T.4, CCITT T.6, or JPEG compression. Otherwise, a TIFF-capable
+ Image I/O codec is necessary for decoding the image.
</p>
<p>
- If you use pixels to specify the size of an SVG graphic the "source resolution" setting
- in the <a href="configuration.html">configuration</a> will be used to determine the
- size of a pixel. The use of pixels to specify sizes is discouraged as they may
- be interpreted differently in different environments.
+ There may be some limitation concerning images in the CMYK color space.
</p>
</section>
- <section id="svg-problems">
- <title>Known Problems</title>
- <ul>
- <li>
-Soft mask transparency is combined with white so that it looks better
-on pdf 1.3 viewers but this causes the soft mask to be slightly lighter
-or darker on pdf 1.4 viewers.
- </li>
- <li>
-There is some problem with a gradient inside a pattern causing a PDF
-error when viewed in acrobat 5.
- </li>
- <li>
-Text is not always handled correctly, it may select the wrong font
-especially if characters have multiple fonts in the font list.
- </li>
- <li>
-More PDF text handling could be implemented.
-It could draw the string using the attributed character iterator
-to handle tspans and other simple changes of text.
- </li>
- <li>
-JPEG images are not inserted directly into the pdf document.
-This area has not been implemented yet since the appropriate
-method in batik is static.
- </li>
- <li>
-Uniform transparency for images and other svg elements that are converted
-into a raster graphic are not drawn properly in PDF. The image is opaque.
- </li>
- </ul>
+ <section id="wmf">
+ <title>WMF</title>
+ <p>
+ Windows Metafiles (WMF) are supported through classes in
+ <a href="ext:xmlgraphics.apache.org/batik">Apache Batik</a>. At the moment, support
+ for this format is experimental and may not always work as expected.
+ </p>
</section>
</section>
- <section id="tiff">
- <title>TIFF</title>
- <p>
- FOP-native TIFF support is limited to PDF and PostScript output only. Also,
- according to user reports, FOP's native support for TIFF is limited to images with the
- following characteristics (all must be true for successful rendering):
- </p>
- <ul>
- <li>single channel images (i.e., bi-level and grayscale only)</li>
- <li>uncompressed images, or images using CCITT T.4, CCITT T.6, or JPEG compression</li>
- <li>images using white-is-zero encoding in the TIFF PhotometricInterpretation tag</li>
- </ul>
- <note>
- Native support in this case means that the images can be embedded into the output format
- without decoding it.
- </note>
- <p><em>JAI:</em> Supports RGB and RGBA only for FOP rendering.</p>
- </section>
- <section id="emf">
- <title>EMF</title>
- <p>Windows Enhanced Metafiles (EMF) are only supported in RTF output.</p>
- </section>
<section id="resolution">
<title>Graphics Resolution</title>
<p>
</p>
<p>
Please note that not all images contain resolution information. If it's not available
- 72 dpi is assumed (the default resolution of PDF and PostScript).
+ the source resolution set on the FopFactory (or through the user configuration XML) is used.
+ The default here is 72 dpi.
</p>
<p>
Bitmap images are generally embedded into the output format at their original resolution
used as a work-around to resample images in FO documents.
</p>
</section>
+ <section id="page-selection">
+ <title>Page selection for multi-page formats</title>
+ <p>
+ Some image formats such as TIFF support multiple pages/sub-images per file. You can
+ select a particular page using a special URI fragment in the form:
+ <uri>#page=<nr>
+ (for example: <code>http://localhost/images/myimage.tiff#page=3</code>)
+ </p>
+ </section>
<section id="caching">
<title>Image caching</title>
<p>
FOP caches images between runs. There is one cache per FopFactory instance. The URI is
used as a key to identify images which means that when a particular URI appears again,
the image is taken from the cache. If you have a servlet that generates a different
- image each time it is called with the same URL you need to use a constantly
- changing dummy parameter on the URL to avoid caching.
+ image each time it is called with the same URI you need to use a constantly
+ changing dummy parameter on the URI to avoid caching.
</p>
<p>
The image cache has been improved considerably in the redesigned code. Therefore, a
projects / xmlgraphics-fop.git / commitdiff