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Scalable vector graphics is a commonly used file format for providing a geometrical description of an image using basic objects such as labels, circles, lines, curves and polygons. An image can be reduced or enlarged to an arbitrary size, and will not suffer image data loss, nor will it become pixelated. SVG makes an excellent format for artwork, diagrams and drawings. SVG images are defined in XML text files. This means that they can be searched, indexed, scripted and, compressed. Since they are XML files, SVG images can be edited with any text editor, but SVG-based drawing programs are also available. However, the rendering engine used by wiki is not perfect, and may cause the image to be shown incorrectly, or differently from how it is displayed in your vector editor of choice. This page enables authors experiencing problems with SVG graphics to obtain some help in getting their images into wiki the way they intend.
Things we can help with
Questions about the SVG format
Using SVG appropriately
When to (or not to) use SVG
What you see is not what you get
- Missing objects from files
- Random filled boxes in the image
- Images that are the wrong size
- Font inconsistencies
- Other weird and wonderful bugs
Questions that you can't find a better place for
The following SVG checkers may help you to detect SVG problems before you upload:
a picture containing SVG1.2-valid flowRoot
Rendering anomalies of small fonts in thumbnail views
Due to copyright restrictions, MediaWiki
cannot use proprietary fonts that are commonly found on several proprietary operating systems. Fonts such as Geneva
require licensing fees to distribute. rsvg will not be able to locate such fonts, and the text will fail to appear in the rendered image. There are three solutions to this issue:
- One can substitute a font that is available on Wikipedia. This approach facilitates editability.
- One can specify a generic font-family such as "sans-serif", "serif", or "monospace", but this can lead to inconsistent rendering. It is better to specify a font available on Wikipedia (such as Liberation Sans) with fallback fonts such as: font-family="Liberation Sans,Arial,Helvetica,sans-serif", in which you define a font-list with similar fonts that at least contain one font for each Operating System such as Wikimedia (e.g. Liberation Sans), Windows (e.g. Arial), Linux (e.g. Liberation Sans), Mac (e.g. Helvetica).
- Since local rendering should be as close as possible to Wikipedia, it should use locally the same font as it will have on Wikipedia, if available. Therefore always define a Wikimedia-font first. Also, Wikimedia has synonyms for substituting fonts, such as "Arial" for "Liberation Sans"; therefore font-family="Arial,DejaVu Sans" will be rendered by "Liberation Sans" and not (as expected) by "DejaVu Sans". (This is because "Liberation Sans" has the same letter size as "Arial" [metric-compatible], so it is less likely to mess up the text flow.)
- Converting the text into paths increases file size, and is therefore generally disfavored (except for text logos, etc.).
- Group the text, create a copy, and convert the copy to paths. Then either:
- move the original, editable non-path text into a separate editable text layer that you make transparent (warning: this might be removed by SVG optimizers), or
- move the original, editable non-path text outside the visible area (example: File:Essigsäuresynthesen.svg).
For ease of subsequent editing and significantly smaller file sizes, substituting the font with an available font is recommended. Many common fonts have non-proprietary alternatives that are similar in typographical style, resulting in minimal disruption to existing images during substitution. For a list of fonts available in Wikipedia, see available fonts
Fonts that are available on Wikimedia servers may or may not be available on a visitor's machine. If the placement or appearance of text in the image is important and there is uncertainty about which fonts are installed on a visitor's machine, then converting text into path information may be necessary.
bad letter-alignment on small font-size
Librsvg calculates the letter-distances inaccurantly for font-sizes of 20px and below.
<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
<text x="20" y="30" font-size="5px">exampletext</text></svg>
<svg viewBox="0 0 1000 1000" xmlns="http://www.w3.org/2000/svg">
<text x="200" y="300" font-size="50px">exampletext</text></svg>
<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
<g transform="scale(0.1)"><text x="200" y="300" font-size="50px">exampletext</text></g></svg>
Missing embedded JPEG images
When a raster graphic
is embedded in an SVG it is encoded into base64
data. That data is then assigned a MIME type
in the <image> element. In the case of an embedded JPEG, the MIME type is "image/jpeg". Older versions of Inkscape
(and possibly other editors) assigned the MIME type "image/jpg". While Inkscape and most web browsers will display such an SVG image just fine, the MediaWiki software that rasterizes the SVG file will have trouble with it. Not recognizing the MIME type "image/jpg" there will simply be an empty space where the image is supposed to be. The fix is to open the SVG file in a text editor, find the <image> element, locate "image/jpg", change it to "image/jpeg" and re-save. At right is an example of this problem. The Commons SVG Checker looks for this problem; see Commons:Commons:Commons SVG Checker/KnownBugs#Checks
Though Web browsers cope with image tags without width and height specified, librsvg ignores such images.
If circle-segmentes are distorted it is often due to reduced spaces between arc-to-flags, see phab:T217990
(the software from which Wikipedia is run) uses the librsvg
-library to rasterize
all of its svg files. The version of the rsvg program that is installed on wiki does not always correctly raster the Inkscape or OpenOffice.org SVG files, and does not recognize some formats in text-editor SVG files. The file manager GNOME Files
relies on librsvg, so it can be used to check the quality before a SVG is uploaded.
There is a simple work-around for the scarcities of librsvg. The operation "Stroke to Path", to be found under Menu>Path in Inkscape or via Ctrl+Alt+C, can be applied to all of the objects that are not rendered correctly. To keep the SVGs editable, this should only be done to the files intended for upload, and these files can be deleted afterwards.
As of February 2014, the objects that must be modified to render correctly by librsvg include:
- Lines with arrow heads (the arrows need to be converted)
- Text, that has been transformed, e.g. "Text on Path"
- Compound objects created with the binary path tools (union, intersect etc.)
Rendering OpenOffice.org SVG files
OpenOffice.org SVG files may require manual modification before being uploaded to Wikipedia. To achieve this:
- Change all fonts to Wikipedia supported fonts as mentioned before. (E.g. change "Sans embedded" to "DejaVu Sans".)
- Add "px" to all font-size references. (E.g. change "font-size:100" to "font-size:100px".)
- Remove all additional x coordinate references in tspan elements. (E.g. change <tspan x="17583 17917 " y="10943"> to <tspan x="17583" y="10943">.)
- [Not required for OO 2.3.0] Explicitly colour all text (e.g. black) by replacing relevant "stroke:none;fill:none" instances with "stroke:none;fill:rgb(0,0,0)" (note that simply explicitly colouring text black in OpenOffice 3.2.1 does not appear to work).
NB: Vector graphics line widths may also need to be set explicitly in OpenOffice.org Draw.
SVG code replacement guide (executing replace all using Nedit regular expressions)
This SVG export procedure has been tested using OO 2.3.0 and OO 3.2.1 with a simple .odg candidate.
Rendering text-editor SVG files
SVG files created from scratch in a text editor may make use of any valid SVG syntax, so long as your browser supports the given version of the SVG specification. On Wikipedia however, SVGs are interpreted by the librsvg-library to create PNG previews at different image sizes. That library only recognizes a subset of all valid SVG syntax, and may render your SVG without many features. In order to bypass these deficiencies in the library, there are certain parameters that need to be formatted in specific ways or be assigned a workaround value in order for librsvg to accurately render views of your SVG file.
<mask> parameter maskUnits="userSpaceOnUse"
The librsvg-library does not interpret
the value of "userSpaceOnUse"
for the parameter maskUnits
correctly. To bypass this issue, replace maskUnits="userSpaceOnUse"
with maskUnits="-10% -10% 120% 120%"
, and the SVG mask will render properly on Wikipedia.
The librsvg-library does not accept
parameter with values separated by spaces. Replace all spaces with commas to bypass this issue: e.g. stroke-dasharray="2 3 2 4"
, not href=
alone, in <use ___/>
In Wikimedia projects, <use xlink:href="#myobjectname" transform="translate(10 10)" /> will render properly if you have specified xmlns:xlink="http://www.w3.org/1999/xlink. Be aware that href= by itself will not work on Wikimedia projects even though it might render properly if directly read by your browser.
General concept above; examples below.
Warming stripes (composite)
I've uploaded .xlsx (Microsoft Excel) spreadsheets that automatically generate XML code for charts in SVG format.
You simply paste your X-Y data into the spreadsheet, and specify image dimensions, number of grid lines, font sizes, etc. The spreadsheet instantly and automatically generates a column of XML code that you simply copy and paste into a text editor and save as an ".svg" file. It produces lean SVG code, avoiding the "extra stuff" that Inkscape inserts, and should save you time.
Click HOW TO
for detailed explanation.
- Warming stripes (download v3.8) produces XML code for applications of Ed Hawkins' warming stripes graphics. User chooses vertical or horizontal stripes; or concentric ellipses, globes (with longitude lines/meridians), hearts, triangles, diamonds, rectangles, pentagrams/stars, hexagons, or octagons; chooses normal or reverse data ordering (updated 3 June 2021). Click here to see examples of warming stripes embedded in different shapes.
- Line charts (download v2.2)— Accepts up to five datasets for LINE charts (example at right) (updated 12 June 2021).
- Vertical bar charts (column charts) (download v1.1)— Accepts up to six datasets for VERTICAL BAR CHARTS (COLUMN CHARTS)—toggle between clustered and stacked charts; user can adjust "Yfloor"—the Y level (usually=0) from which columns rise or fall; user chooses to keep or ignore negative input values (example at right) (updated 30 April 2021).
- Horizontal bar charts (download v1.0)— Accepts up to six datasets for HORIZONTAL BAR CHARTS—toggle between clustered and stacked charts; user can adjust "Yfloor"—the value (usually=0) from which bars extend; user chooses to keep or ignore negative input values (updated 9 June 2021).
- Scatter plots (download v1.0)— Accepts up to five datasets for SCATTER PLOTS (updated 14 June 2021).
- Pie charts (download v1.0)— Accepts a series of up to 36 items for PIE CHARTS (updated 25 March 2021).
If you have a tricky SVG file with a problem not described, or can't quite figure out what the previous section was talking about, you can simply ask for assistance by posting a quick note hereafter
that outlines the problem, as well as providing links to the files that are exhibiting these problems. Don't forget to sign your name with four tilde symbols (~~~~) and an editor will attempt to reply here to help!
When you are happy that a request has been fulfilled, just leave a note so that the request can be archived later, as needed.
Signature of Libuše Šafránková
Hi, would someone please render this signature: File:LŠ podpis.jpg
? The actress passed away this week. Thanks, --Pakeha
) 16:02, 11 June 2021 (UTC)
Thanks for your advice! --Pakeha
) 19:39, 13 June 2021 (UTC)
vector showing up fully transparent
Trying to upload a vector on the commons and it keeps showing up as transparent. When I put onto Inkscape and the file preview before uploading, the logo shows. Any reason for this?
It's possibly the mask="url(#mask-2)"
attributes that occur six times on <path />
tags - I can't find where mask-2
is defined. Have you tried putting the image through c:COM:Commons SVG Checker
) 07:58, 16 July 2021 (UTC)
: I put it through the SVG checker and while it doesnt show there, it does show when I click on the "original file"
button on commons. I also don't know how to resolve it since I just took it directly from the arena's website. Troutfarm27 (Talk)
03:14, 17 July 2021 (UTC)
Last edited on 21 July 2021, at 09:47
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