Andreas Gohr
Andreas Gohr

Reputation: 4935

Convert SVG to transparent PNG with antialiasing, using ImageMagick

I want to convert SVG images to PNG files with transparent background and anti-aliased edges (using semi-transparent pixels). Unfortunately I can't get ImageMagick to do the anti-aliasing, the edges always look terrible. Here's what I tried:

convert +antialias -background transparent  in.svg -resize 25x25 out.png

Any ideas or a different command line tool I could use?

Upvotes: 92

Views: 65503

Answers (8)

Micah
Micah

Reputation: 17798

Instead of -background transparent, use -background none.

convert -background none in.svg out.png

NOTE: The order of the arguments is important.

Upvotes: 139

yourstruly
yourstruly

Reputation: 1002

For me that works for svg to png:

convert ${src} \
    -transparent white \
    -background none \
    -resize 345x345 \
    res/drawable-xxxhdpi/${dest}

Upvotes: 5

halfer
halfer

Reputation: 20440

Inkscape will do this:

inkscape \
    --export-png=out.png --export-dpi=200 \
    --export-background-opacity=0 --without-gui in.svg

Update

The terminology has changed: all the export params suppress gui, and the output parameter is now simply based on the file type. For example, a type of png will cause a file in /path/to/picture.svg to be exported as /path/to/picture.png (caution: this overwrites output).

inkscape \
    --export-type=png --export-dpi=200 \
    --export-background-opacity=0 picture.svg

Note cited wiki has quotes on --export-type=png, which is incorrect.

Also if don't have Inkscape command line, MacOS can access via bash directly:

/Applications/Inkscape.app/Contents/MacOS/inkscape

Upvotes: 60

WoodrowShigeru
WoodrowShigeru

Reputation: 1594

I get better, already nicely antialiased results if I replace -resize with -scale. Then, the antialias flag isn't even necessary.

Upvotes: 0

C Würtz
C Würtz

Reputation: 864

I add a rect as background. The embed CSS hide the background. Then I catch its color for setting the transparent attribute of ImageMagick.


SVG file:

<?xml version="1.0" ?>
<!DOCTYPE svg  PUBLIC '-//W3C//DTD SVG 1.1//EN'  'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd'>
<svg 
    version="1.1" xml:space="preserve" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"
    width="500px" height="500px"
    viewBox="0 0 500 500" 
    enable-background="new 0 0 500 500" 
    >
<defs>
    <style>
        #background { display: none; }
    </style>
</defs>
<rect id="background" x="0" y="0" width="500" height="500" fill="#e8e437"/>
<!-- beginning of the sketch -->
<g fill="#000" text-anchor="middle"font-size="112">
    <text y="350" x="192">OK</text>
</g>
<!-- end of the sketch -->
</svg>

bash script

#!/bin/bash


BASE_DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )
SVG_DIR="$BASE_DIR/import"
PNG_DIR="$BASE_DIR/export"

for f in `ls $SVG_DIR/*.svg`
do
    g="$PNG_DIR/$(basename "$f" .svg).png"
    BGCOLOR=`grep 'id="background"' $f \
        | sed 's/.* fill="\([^"]*\)".*/\1/'`

    convert $f -transparent "$BGCOLOR" $g
done

Upvotes: -1

Yurii Rabeshko
Yurii Rabeshko

Reputation: 631

Adding the -transparent white option solves the problem particularly in my case because background isn't removed completely (unfortunately light shadow is present). So I'm using IMHO more clearer solution that fully removes background with ImageMagic:

convert -channel rgba -background "rgba(0,0,0,0)" in.svg out.png

It sets a fully transparent black color as the background through the RGBA channel.

Upvotes: 5

chiliNUT
chiliNUT

Reputation: 19573

The way I learned how to do this was from the methodology found here: How to convert a .eps file to a high quality 1024x1024 .jpg?

It is the same idea as @halfer's solution with inkscape--to jack up the DPI first--but you can accomplish the same thing in just imagemagick using the -density option.

convert -density 200 in.svg -resize 25x25 -transparent white out.png

Upvotes: 12

sleeper
sleeper

Reputation: 528

Actually, reading imagemagick documentation:

-antialias

Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines. By default, objects (e.g. text, lines, polygons, etc.) are antialiased when drawn. Use +antialias to disable the addition of antialiasing edge pixels. This will then reduce the
number of colors added to an image to just the colors being directly drawn. That is, no mixed >colors are added when drawing such objects.

the +antialias will indeed disable antialiasing.

Upvotes: 19

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