librsvg/rsvg-convert.rst

.. rsvg-convert(1):

============
rsvg-convert
============

-----------------------------------------------------------------
Render SVG documents to PNG images, or convert them to PDF or PS.
-----------------------------------------------------------------

SYNOPSIS
========

Convert an SVG to PNG at its "natural size" and write it to standard
output:

   **rsvg-convert** *input.svg* **>** *output.png*

Specify an output filename; the input filename must be the last
argument:

   **rsvg-convert** **--output=**\ *output.png* *input.svg*

Configure dots-per-inch (DPI) for SVGs that have physical units, as in
``<svg width="5cm" height="3cm">`` - the default is 96 DPI:

   **rsvg-convert** **--dpi-x=**\ *300* **--dpi-y=**\ *300* *input.svg*
   **>** *output.png*

Render an SVG at a specific pixel size, scaled proportionally:

   **rsvg-convert** **--width=**\ *1024* **--height=**\ *768*
   **--keep-aspect-ratio** *input.svg* **>** *output.png*

DESCRIPTION
===========

``rsvg-convert`` renders SVG documents into PNG raster images, or
converts them to PDF or PS as vector objects. By default
``rsvg-convert`` will render an SVG document to a raster PNG image and
write it to standard output:

   **rsvg-convert** *input.svg* **>** *output.png*

To select another format, use the ``--format`` option:

   **rsvg-convert --format=pdf** *input.svg* **>** *output.pdf*

You can use ``rsvg-convert`` as part of a pipeline; without an argument
for the input filename it will read the document from standard input:

   **cat** *input.svg* **\|** **rsvg-convert** **>** *output.png*


SPECIFYING THE RENDERED SIZE
----------------------------

You can use the ``--width`` and ``--height`` options to specify the size
of the output image. Most of the time you should specify
``--keep-aspect-ratio`` to scale the image proportionally; for
compatibility with old versions this is not the default.

   **rsvg-convert** **--width=**\ *100* **--height=**\ *200*
   **--keep-aspect-ratio** *input.svg* **>** *output.png*

You can also specify dimensions as CSS lengths, for example ``10px`` or
``8.5in``. The unit specifiers supported are as follows:

   == ==========================================
   px pixels (the unit specifier can be omitted)
   in inches
   cm centimeters
   mm millimeters
   pt points, 1/72 inch
   pc picas, 1/6 inch
   == ==========================================

The following will create a 600*900 pixel PNG, or 2*3 inches at 300
dots-per-inch:

   **rsvg-convert** **--width=**\ *2in* **--height=**\ *3in*
   **--keep-aspect-ratio** **--dpi-x=**\ *300* **--dpi-y=**\ *300*
   *input.svg* **>** *output.png*

This will scale an SVG document to fit in an A4 page and convert it to
PDF:

   **rsvg-convert** **--format=**\ *pdf* **--width=**\ *210mm*
   **--height=**\ *297mm* **--keep-aspect-ratio** *input.svg* **>**
   *output.pdf*


SPECIFYING A PAGE SIZE
----------------------

By default the size of the output comes from the rendered size, which
can be specified with the ``--width`` and ``--height`` options, but you
can specify a page size independently of the rendered size with
``--page-width`` and ``--page-height``, together with ``--top`` and
``--left`` to control the position of the rendered image within the
page.  In short:

* ``--page-width`` and ``--page-height`` together - set the page size.
* ``--top`` and ``--left`` - set the margins.
* ``--width`` and ``--height`` - set the rendered size.

This will create a PDF with a landscape A4 page, by scaling an SVG
document to 10*10 cm, and placing it with its top-left corner 5 cm away
from the top and 8 cm from the left of the page:

   **rsvg-convert** **--format=**\ *pdf* **--page-width=**\ *297mm*
   **--page-height=**\ *210mm* **--width=**\ *10cm*
   **--height=**\ *10cm* **--keep-aspect-ratio** **--top=**\ *5cm*
   **--left=**\ *8cm* *input.svg* **>** *output.pdf*


SPECIFYING A SCALE FACTOR INSTEAD OF A RENDERED SIZE
----------------------------------------------------

The ``--zoom`` option lets you scale the natural size of an SVG
document. For example, if *input.svg* is a document with a declared size
of 100*200 pixels, then the following command will render it at 250*500
pixels (zoom 2.5):

   **rsvg-convert** **--zoom=2.5** *input.svg* **>** *output.png*

You can limit the maximum scaled size by specifying the ``--width`` and
``--height`` options together with ``--zoom``.  Here, the image will be
scaled 10x, but limited to 1000*1000 pixels at the most:

   **rsvg-convert** **--zoom=10** **--width=1000** **--height=1000**
   *input.svg* **>** *output.png*

If you need different scale factors for the horizontal and vertical
dimensions, use the ``--x-zoom`` and ``--y-zoom`` options instead of
``--zoom``.


CREATING A MULTI-PAGE DOCUMENT
------------------------------

The "pdf", "ps", and "eps" output formats support multiple pages. These
can be created by combining multiple input SVG files. For example, this
PDF file will have three pages:

   **rsvg-convert** **--format=**\ *pdf* *page1.svg* *page2.svg* *page3.svg*
   **>** *out.pdf*

The size of each page will be computed, separately, as described in the
**DEFAULT OUTPUT SIZE** section. This may result in a PDF being produced
with differently-sized pages. If you need to produce a PDF with all
pages set to exactly the same size, use the **--page-width** and
**--page-height** options.

For example, the following command creates a three-page PDF out of
three SVG documents. All the pages are portrait US Letter, and each
SVG is scaled to fit so that there is a 1in margin around each page
(hence the width of 6.5in and height of 9in for the rendered size).

   **rsvg-convert** **--format=**\ *pdf* **--page-width=**\ *8.5in*
   **--page-height=**\ *11in* **--width=**\ *6.5in* **--height=**\ *9in*
   **--keep-aspect-ratio** **--top=**\ *1in* **--left=**\ *1in*
   *pg1.svg* *pg2.svg* *pg3.svg* **>** *out.pdf*


CONVERSION OF PIXELS BASED ON THE DOTS-PER-INCH
-----------------------------------------------

**rsvg-convert** uses the ``--dpi-x`` and ``--dpi-y`` options to
configure the dots-per-inch (DPI) by which pixels will be converted
to/from physical units like inches or centimeters. The default for both
options is 96 DPI.

Consider this example SVG, which is nominally declared to be 2*3 inches
in size:

::

   <svg xmlns="http://www.w3.org/2000/svg" width="2in" height="3in">
     <!-- graphical objects here -->
   </svg>

The following commands create PNGs of different sizes for the example
SVG above:

   **rsvg-convert** *two-by-three.svg* **>** *output.png* #### creates a
   192*288 pixel PNG

   **rsvg-convert** **--dpi-x=**\ *300* **--dpi-y=**\ *300*
   *two-by-three.svg* **>** *output.png* #### creates a 600*900 pixel
   PNG

Note that the final pixel dimensions are rounded up to the nearest
pixel, to avoid clipping off the right/bottom edges. In the following
example, **rsvg-convert** will generate a PNG 300x300 pixels in size:

   **rsvg-convert** **--width=**\ *299.5* **--height=**\ *299.4*
   *input.svg* **>** *output.png* #### outputs 300x300 pixel PNG with a
   fractionally-scaled image

If you specify dimensions in physical units, they will be multiplied by
the dots-per-inch (DPI) value to obtain dimensions in pixels. For
example, this will generate a 96x96 pixel PNG, since it is 1x1 inch at
the default 96 DPI:

   **rsvg-convert** **--width=**\ *1in* **--height=**\ *1in* *input.svg*
   **>** *output.png* #### outputs 96x96 pixel PNG

Correspondingly, this will generate a 300x300 pixel PNG, since it is 1x1
inch at 300 DPI:

   **rsvg-convert** **--width=**\ *1in* **--height=**\ *1in*
   **--dpi-x=**\ *300* **--dpi-y=**\ *300* *input.svg* **>**
   *output.png* #### outputs 300x300 pixel PNG


DEFAULT OUTPUT SIZE
-------------------

If you do not specify ``--width`` or ``--height`` options for the output
size, **rsvg-convert** will figure out a "natural size" for the SVG as
follows:

-  **SVG with width and height in pixel units (px):** ``<svg
   width="96px" height="192px">`` For PNG output, those same dimensions
   in pixels are used. For PDF/PS/EPS, that pixel size is converted to
   physical units based on the DPI value (see the ``--dpi-x`` and
   ``--dpi-y`` options),

-  **SVG with width and height in physical units:** ``<svg width="1in"
   height="2in">`` For PNG output, the ``width`` and ``height``
   attributes get converted to pixels, based on the DPI value (see the
   ``--dpi-x`` and ``--dpi-y`` options). For PDF/PS/EPS output, the
   width/height in physical units define the size of the PDF unless you
   specify options for the page size; see **SPECIFYING A PAGE SIZE**
   above.

-  **SVG with viewBox only:** ``<svg viewBox="0 0 20 30">`` The size of
   the ``viewBox`` attribute gets used for the pixel size of the image
   as in the first case above.

-  **SVG with width and height in percentages:** ``<svg width="100%"
   height="100%" viewBox="0 0 20 30">`` Percentages are meaningless
   unless you specify a viewport size with the ``--width`` and
   ``--height`` options. In their absence, **rsvg-convert** will just
   use the size of the ``viewBox`` for the pixel size, as described
   above.

-  **SVG with no width, height, or viewBox:** **rsvg-convert** will
   measure the extents of all graphical objects in the SVG document and
   render them at 1:1 scale (1 pixel for each CSS px unit). It is
   strongly recommended that you give SVG documents an explicit size
   with the ``width``, ``height``, or ``viewBox`` attributes.


BACKGROUND COLOR
----------------

You can use the ``--background-color`` option (``-b`` for short) to
specify the background color that will appear in parts of the image that
would otherwise be transparent. This option accepts the same syntax as
the CSS ``color`` property, so you can use ``#rrggbb`` syntax, or CSS
named colors like ``white``, or ``rgba()``.

   **rsvg-convert** **--background-color=**\ *white* *input.svg* **>**
   *output.png* #### opaque white

..

   **rsvg-convert** **-b** *'#ff000080'* *input.svg* **>** *output.png*
   #### translucent red - use shell quotes so the # is not interpreted
   as a comment


SELECTING A LANGUAGE FOR MULTI-LANGUAGE SVG
-------------------------------------------

An SVG document can use the ``<switch>`` element and children with the
``systemLanguage`` attribute to provide different content depending on
the user's language. For example:

::

   <svg xmlns="http://www.w3.org/2000/svg" width="200" height="100">
     <rect width="200" height="100" fill="white"/>
     <g transform="translate(30, 30)" font-size="20">
       <switch allowReorder="yes">
         <text systemLanguage="es">Español</text>
         <text systemLanguage="de">Deutsch</text>
         <text systemLanguage="fr">Français</text>
         <text>English fallback</text>
       </switch>
     </g>
   </svg>

You can use the ``--accept-language`` option to select which language to
use when rendering. This option accepts strings formatted like an HTTP
Accept-Language header, which is a comma-separated list of BCP47
language tags: https://www.rfc-editor.org/info/bcp47

   **rsvg-convert** **--accept-language=**\ *es-MX* *input.svg* **>**
   *output.png* #### selects Mexican Spanish; renders "Español".


USER STYLESHEET
---------------

You can include an extra CSS stylesheet to be used when rendering an
SVG document with the ``--stylesheet`` option. The stylesheet will
have the CSS **user origin**, while styles declared in the SVG document
will have the CSS **author origin**.

   **rsvg-convert** **--stylesheet=**\ *extra-styles.css* *input.svg*
   **>** *output.png*

Please note that per the cascading rules of CSS, a user stylesheet
does not necessarily override the styles defined in an SVG document.
To override them reliably, you need to set your extra styles to
``!important``.

According to the CSS Cascading specification
(`https://www.w3.org/TR/css-cascade-4/#cascade-sort`), style
declarations have the following precedence.  Declarations from origins
later in the list win over declarations from earlier origins:

- Normal user agent declarations (librsvg's own stylesheets).
- Normal user declarations (from your user stylesheet).
- Normal author declarations (from the SVG document).
- ``!important`` author declarations (from the SVG document).
- ``!important`` user declarations (from your user stylesheet).
- ``!important`` user agent declarations (librsvg's own stylesheets).

After that, the CSS specificity and order of appearance of
declarations get taken into account.

Consider the following *input.svg*; notice how the rectangle has
``fill="red"`` as a presentation attribute, and a ``recolorable``
class:

::

    <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
      <rect width="200" height="100" fill="white"/>

      <rect class="recolorable" x="10" y="10" width="50" height="50" fill="red"/>

      <text x="10" y="80" font-size="20" fill="red">Hello</text>
    </svg>

And this is *extra-styles.css*:

::

    .recolorable { fill: blue !important; }

    text { fill: green !important; }

Then the PNG created by the command above will have these elements:

- A blue square instead of a red one, because of the selector for the
  the ``recolorable`` class.  The ``fill: blue !important;``
  declaration takes precedence over the ``fill="red"`` presentation
  attribute.

- Text in green, since its ``fill="red"`` gets overridden with `fill:
  green !important`.


OPTIONS
=======

..
   ## ATTENTION ##

   Below is the format for documenting an option:

   [``-<short-name>``, ]``--<long-name>``[ *<value-name>*]
      <main-description>
      [<value-description>]
      [<default-description>]
      [<extra-description>] ...

   where:

   - *short-name* is the short option name, if it has one.
   - *long-name* is the long option name (which is required).
   - *value-name* is the name of the option's value, if it takes one.
     If present, it must be a sequence of alphabetic characters, optionally
     containing `-`, `.` or `_` (one at a time) **in-between** the letters.
   - *main-description* is a (preferably brief) description of the option.
   - *value-description* is a description of the option's value, if it takes
     one. For an option with a fixed set of possible values, this segment is
     required and **all** the values must be listed out (backquoted and
     separated by ", ") as in "Possible values are ``foo``, ``bar``, ``baz``.".
   - *default-description* is a description of the option's default value
     (if it takes a value) or behaviour when not specified. This segment is
     typically not neccesary for boolean/flag options.
   - *extra-description* can be anything else such as further description,
     "See ..." or description of interaction with another option.
     This segment may be repeated as many times as neccessary.
   - for ease of updating and parsing, each description segment must:
     
     - be a **single sentence** (ending with a `.`), with the exception of
       *extra-description*.
     - start on a new line, with the exception of subsequent
       *extra-description*.

   - `<`, `>`, `[` and `]` in this format specification are not literal
     i.e should not appear in an actual instance.
   - any part of this format specification within `[ ]` is optional except
     when stated otherwise.

   If any change is made to this format, please see to it that the
   `ci/check-rsvg-convert-options` crate is updated accordingly, if neccesary.

.. If any change is made to the options in this document, please run:

     $ cargo run -p ci --bin check-rsvg-convert-options

   and make the neccesary corrections, if there are any errors.

.. The comment below is used as a marker by `ci/check-rsvg-convert-options`.
   If the comment is modfied, please ensure the crate is updated accordingly.

.. START OF OPTIONS


GENERAL OPTIONS
---------------

``-f``, ``--format`` *format*
   Output format for the rendered document.
   Possible values are ``png``, ``pdf``, ``pdf1.4``, ``pdf1.5``, ``pdf1.6``,
   ``pdf1.7``, ``ps``, ``eps``, ``svg``.
   Default is ``png``.
   See the section "PDF VERSIONS" for more detail on what each one allows.

``-o``, ``--output`` *filename*
   Specify the output filename.
   If unspecified, outputs to standard output.

``-v``, ``--version``
   Display what version of rsvg-convert you are running.

``-?``, ``--help``
   Display a summary of usage and options.


SIZE AND POSITION
-----------------

In the following, *length* values must be specified with CSS <length>
syntax: https://developer.mozilla.org/en-US/docs/Web/CSS/length.
For example, ``640px`` or ``25cm``.

``--page-width`` *length*
   Page width of the output document.
   The default is to use the image's width as modified by the options
   below.
   Must be used together with ``--page-height``.

``--page-height`` *length*
   Page height of the output document.
   The default is to use the image's height as modified by the options
   below.
   Must be used together with ``--page-width``.

``--top`` *length*
   Distance between top edge of the page and the rendered image.
   Default is 0.

``--left`` *length*
   Distance between left edge of the page and the rendered image.
   Default is 0.

``-w``, ``--width`` *length*
   Width of the rendered image.
   If unspecified, the natural width of the image is used.
   See the section "SPECIFYING DIMENSIONS" above for details.

``-h``, ``--height`` *length*
   Height of the rendered image.
   If unspecified, the natural height of the image is used.
   See the section "SPECIFYING DIMENSIONS" above for details.

``-a``, ``--keep-aspect-ratio``
   Specify that the aspect ratio is to be preserved.
   If not specified, aspect ratio will not be preserved.
   The image is scaled proportionally to fit in the ``--width`` and
   ``--height``.

``-d``, ``--dpi-x`` *number*
   Set the X resolution of the image in pixels per inch.
   Default is 96 DPI.

``-p``, ``--dpi-y`` *number*
   Set the Y resolution of the image in pixels per inch.
   Default is 96 DPI.

``-x``, ``--x-zoom`` *number*
   Horizontal scaling factor.
   Default is 1.0.

``-y``, ``--y-zoom`` *number*
   Vertical factor factor.
   Default is 1.0.

``-z``, ``--zoom`` *number*
   Horizontal and vertical scaling factor.
   Default is 1.0.


CONTROLLING THE RENDERED APPEARANCE
-----------------------------------

``-b``, ``--background-color`` *color*
   Specify the background color.
   The *color* must be specified in CSS <color> syntax:
   https://developer.mozilla.org/en-US/docs/Web/CSS/color_value;
   for example, ``black``, ``#ff0000``, ``rgba(0.0, 1.0, 0.0, 1.0)``.
   The default is ``none``; this will create transparent PNGs,
   or PDF/PS/EPS without a special background.

``-s``, ``--stylesheet`` *filename.css*
   Filename of a custom CSS stylesheet.

``-l``, ``--accept-language`` *language-tags*
   Specify which languages will be used for SVG documents with multiple
   languages.
   The value is formatted like an HTTP Accept-Language header, which
   is a comma-separated list of BCP47 language tags:
   https://www.rfc-editor.org/info/bcp47 e.g ``es-MX,fr,en``.
   The default is to use the language specified by environment
   variables; see the section "ENVIRONMENT VARIABLES" below.


OPTIONS SPECIFIC TO PDF/PS/EPS OUTPUT
-------------------------------------

``--keep-image-data``
   For SVG documents that reference PNG or JPEG images, include the
   original, compressed images in the final output, rather than
   uncompressed RGB data.
   This is the default behavior for PDF and (E)PS output.

``--no-keep-image-data``
   Do not include the original, compressed images but instead embed
   uncompressed RGB data in PDF or (E)PS output.
   This will most likely result in larger documents that are slower
   to read.


MISCELLANEOUS
-------------

``-i``, ``--export-id`` *object-id*
   Allows to specify an SVG object that should be exported based on its
   XML ``id`` attribute.
   If not specified, all objects will be exported.

``-u``, ``--unlimited``
   Turn off the XML parser's guards.
   The XML parser has some guards designed to mitigate large CPU or
   memory consumption in the face of malicious documents. It may also
   refuse to resolve ``data:`` URIs used to embed image data in SVG
   documents. If you are running into such issues when converting a
   SVG, this option allows to turn off these guards.

``--testing``
   For developers only: render images for librsvg's test suite.

``--completion`` *shell-name*
   Generate a script for a shell's Tab completion.
   Possible values are ``bash``, ``elvish``, ``fish``, ``powershell``,
   ``zsh``.
   Rsvg-convert will then write a suitable script to standard output.


.. END OF OPTIONS

.. The comment above is used as a marker by `ci/check-rsvg-convert-options`.
   If the comment is modfied, please ensure the crate is updated accordingly.


ENVIRONMENT VARIABLES
=====================

``SOURCE_DATE_EPOCH``
   If the selected output format is PDF, this variable can be used to
   control the CreationDate in the PDF file. This is useful for
   reproducible output. The environment variable must be set to a
   decimal number corresponding to a UNIX timestamp, defined as the
   number of seconds, excluding leap seconds, since 01 Jan 1970 00:00:00
   UTC. The specification for this can be found at
   https://reproducible-builds.org/specs/source-date-epoch/

**System language**
   Unless the ``--accept-language`` option is specified, the default is
   to use the system's environment to detect the user's preferred
   language. This consults the environment variables ``LANGUAGE``,
   ``LC_ALL``, ``LC_MESSAGES``, and ``LANG``.

PDF VERSIONS
============

The ``--format=pdf`` option makes rsvg-convert output the latest
version of PDF that it supports.  Normally this is the right thing to
do, except when you have tools that consume the resulting PDFs but
only support certain versions.

For example, LaTeX tools like pdflatex may issue a warning if you try
to include a PDF image that uses a newer version than the surrounding
document, similar to

  *PDF inclusion: found PDF version <1.7> but at most version <1.5> allowed*

In this case, you may need to restrict the PDF version that
rsvg-convert produces.  Instead of ``--format=pdf``, you can use the
following:

``--format=pdf1.4``
  Does not use PDF object streams; files may be bigger as they allow for less compression.

``--format=pdf1.5``
  Allows creating PDFs where text can be selected and searched.

``--format=pdf1.6``
  No special behavior.

``--format=pdf1.7``
  Allows including UTF-8 filenames in link objects reliably.

If you are using LaTeX tooling, you may want to research options like
``\pdfminorversion=6``.


MORE INFORMATION
================

Librsvg source repository and bug tracker: https://gitlab.gnome.org/GNOME/librsvg

Wiki project page: https://gnome.pages.gitlab.gnome.org/librsvg/

SVG1.1 specification: https://www.w3.org/TR/SVG11/

SVG2 specification: https://www.w3.org/TR/SVG2

GNOME project page: https://www.gnome.org/