ChatGPT解决这个技术问题 Extra ChatGPT

How to convert a SVG to a PNG with ImageMagick?

I have a SVG file that has a defined size of 16x16. When I use ImageMagick's convert program to convert it into a PNG, then I get a 16x16 pixel PNG which is way too small:

convert test.svg test.png

I need to specify the pixel size of the output PNG. -size parameter seems to be ignored, -scale parameter scales the PNG after it has been converted to PNG. The best result up to now I got by using the -density parameter:

convert -density 1200 test.svg test.png

But I'm not satisfied, because I want to specify the output size in pixels without doing math to calculate the density value. So I want to do something like this:

convert -setTheOutputSizeOfThePng 1024x1024 test.svg test.png

So what is the magic parameter I have to use here?

e.g. -size 1024x1024 is working fine, what is your imagemagick version?
ImageMagick-6.9.0-Q16. convert -resize 1024x1024 foo.svg foo.png works fine.
@Jichao -resize just stretches the converted image, with poor quality results.
convert -size 1024x1024 test.svg test.png works fine with ImageMagick 7.0.7-0 Q16 (current version in Chocolatey repo for Windows). Just make sure that -size appears before the input filename, else a 16x16 picture will be upscaled to give a blurry result.

N
Nico Schlömer

I haven't been able to get good results from ImageMagick in this instance, but Inkscape does a nice job of scaling an SVG on Linux and Windows:

# Inkscape v1.0+
inkscape -w 1024 -h 1024 input.svg -o output.png
# Inkscape older than v1.0
inkscape -z -w 1024 -h 1024 input.svg -e output.png

Note that you can omit one of the width/height parameters to have the other parameter scaled automatically based on the input image dimensions.

Here's the result of scaling a 16x16 SVG to a 200x200 PNG using this command:

https://i.stack.imgur.com/ybxpA.png

https://i.stack.imgur.com/mDPMo.png


+1 as far as imagemagick is concerned. There seem to be problem with the SVG engine. In most cases I wasn't able to get accurate results with it. Inkscape, OTOH, works perfectly fine.
I think Inkscape is the single most impressive example of OSS after Linux itself. Thanks for the tip!
Works nicely on OSX too.
On OSX, with Inkscape installed for X11, it worked for me using: /Applications/Inkscape.app/Contents/Resources/bin/inkscape -z -e test.png -w 1024 -h 1024 test.svg
@Rörd To keep background transparent with ImageMagick, use -background none command line option.
A
Ali Shakiba

Try svgexport:

svgexport input.svg output.png 64x
svgexport input.svg output.png 1024:1024

svgexport is a simple cross-platform command line tool that I have made for exporting svg files to jpg and png, see here for more options. To install svgexport install npm, then run:

npm install svgexport -g

Edit: If you find an issue with the library, please submit it on GitHub, thanks!


svgexport worked great for me. Output matches browser rendering much more closely than ImageMagick.
this worked well for me as well. Real time saver compared to doing it manually in a GUI tool. Quite difficult to find a GUI app on mac in the cheaper range anyway that handles SVG well
svgexport didn't do anything for me on OSX, just ended up with blank image
Works great, but produces a huge image. Using optipng, I was able to compress my text logo down from 3 megabytes to ~20kB.
evgexport creates HUGE png files depending on the size. Recommend svg2png which also uses PhantomJS for export, but creates much smaller images.
D
Dheeraj Bhaskar

This is not perfect but it does the job.

convert -density 1200 -resize 200x200 source.svg target.png

Basically it increases the DPI high enough (just use an educated/safe guess) that resizing is done with adequate quality. I was trying to find a proper solution to this but after a while decided this was good enough for my current need.

Note: Use 200x200! to force the given resolution


Opacity and shadows lost in my case.
I don't have complex svg so this worked for me. -resize 200% did not work and I had to specify size in pixels.
@jiyinyiyong To keep background transparent with ImageMagick, use -background none command line option. To keep image ratio, you also could specify only one dimension like -resize 200 for width or -resize x200 for height. See: imagemagick.org/script/command-line-processing.php#geometry for exhaustive ImageMagick geometry options.
doesn't work for me either. The result is all blurry.
And the batch version is for file in ./*.svg; do convert -density 1200 -background none -resize 200x200 $file `basename $file .svg`.png; done
J
Jose Alban

If you are on MacOS X and having problems with Imagemagick's convert, you might try reinstalling it with RSVG lib. Using HomeBrew:

brew remove imagemagick
brew install imagemagick --with-librsvg

Verify that it's delegating correctly:

$ convert -version
Version: ImageMagick 6.8.9-8 Q16 x86_64 2014-12-17 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2014 ImageMagick Studio LLC
Features: DPC Modules
Delegates: bzlib cairo fontconfig freetype jng jpeg lcms ltdl lzma png rsvg tiff xml zlib

It should display rsvg.


Worked perfectly for me - the default convert did convert svg to png, but the results were hopeless; after reinstalling, they're perfect. Also, conversion is significantly faster.
This worked me on Mac OSX. I don't find the new conversion faster, but much much more accurate. I highly recommend all Mac OSX users give this a try.
This should be the accepted answer, oh well. Thank you, worked like a charm, and I never would have known to take these steps otherwise
On mojave i get invalid option: --with-librsvg
@zaitsman Probably too late, but... The argument option has changed, try with --with-rsvg. And I think it needs the librsvg2-bin package to be installed. See gist.github.com/maxivak/1476f7e979879da9f75371a86d5627b5
m
masterxilo

Inkscape doesn't seem to work when svg units are not px (e.g. cm). I got a blank image. Maybe, it could be fixed by twiddling the dpi, but it was too troublesome.

Svgexport is a node.js program and so not generally useful.

Imagemagick's convert works ok with:

 convert -background none -size 1024x1024 infile.svg outfile.png

If you use -resize, the image is fuzzy and the file is much larger.

BEST

rsvg-convert -w 1024 -h 1024 infile.svg -o outfile.png

It is fastest, has the fewest dependencies, and the output is about 30% smaller than convert. Install librsvg2-bin to get it:

sudo apt install -y librsvg2-bin

There does not appear to be a man page but you can type:

rsvg-convert --help

to get some assistance. Simple is good.


This is easily the best answer (I don't know why twenty different answers give the same imagemagick response); it preserves colors and shadows and doesn't mangle anything. However, to match the imagemagick resize behavior (in particular, WxH means scale image to fit in a box of that size, preserving aspect ratio), the -a parameter should be used with rsvg.
This mangled my images, all sorts of weird artifacts. inkscape did a better job.
FYI, the current install command is brew install librsvg and the conversion command is rsvg-convert.
I found librsvg (or rsvg-convert in case of Arch) to give the best and most consistent results when converting complicated svgs to png. Follow up with optipng to reduce output file size.
In Ubuntu: sudo apt install librsvg2-bin; rsvg-convert input.svg -o output.png
J
João Pimentel Ferreira

After following the steps in Jose Alban's answer, I was able to get ImageMagick to work just fine using the following command:

convert -density 1536 -background none -resize 100x100 input.svg output-100.png

The number 1536 comes from a ballpark estimate of density, see this answer for more information.


use -size instead, apparently in some IM version resize makes image blurry
w
waldyrious

In order to rescale the image, the option -density should be used. As far as I know the standard density is 72 and maps the size 1:1. If you want the output png to be twice as big as the original svg, set the density to 72*2=144:

convert -density 144 source.svg target.png

Note that convert options have to be before the input file. I.e. convert source.svg -density 144 target.png won't rescale the image.
Actually the standard density seems to be 90. So it would be convert -density 180 source.svg target.png
f
fmw42

In ImageMagick, one gets a better SVG rendering if one uses Inkscape or RSVG with ImageMagick than its own internal MSVG/XML rendered. RSVG is a delegate that needs to be installed with ImageMagick. If Inkscape is installed on the system, ImageMagick will use it automatically. I use Inkscape in ImageMagick below.

There is no "magic" parameter that will do what you want.

But, one can compute very simply the exact density needed to render the output.

Here is a small 50x50 button when rendered at the default density of 96:

convert button.svg button1.png

https://i.stack.imgur.com/4PmEW.png

Suppose we want the output to be 500. The input is 50 at default density of 96 (older versions of Inkscape may be using 92). So you can compute the needed density in proportion to the ratios of the dimensions and the densities.

512/50 = X/96
X = 96*512/50 = 983

convert -density 983 button.svg button2.png

https://i.stack.imgur.com/885O6.png

In ImageMagick 7, you can do the computation in-line as follows:

magick -density "%[fx:96*512/50]" button.svg button3.png

or

in_size=50
in_density=96
out_size=512

magick -density "%[fx:$in_density*$out_size/$in_size]" button.svg button3.png

+1 for the magical fx expression which avoids a separate command, or use of a calculator. As a side note, if you run identify -format "%x x %y (%w x %h) file.svg, you will also get the width and height for the default density in the output (which you need for $in_size in the formula)!
you can do it even in 1 line stackoverflow.com/a/66901038/1597158
Thanks! It works like a charm! and if you add the option -background none you'll also have a .png with transparent background!
m
mloughran

On macOS using brew, using librsvg directly works well

brew install librsvg
rsvg-convert test.svg -o test.png

Many options are available via rsvg-convert --help


M
MestreLion

For simple SVG to PNG conversion I found cairosvg (https://cairosvg.org/) performs better than ImageMagick. Steps for install and running on all SVG files in your directory.

pip3 install cairosvg

Open a python shell in the directory which contains your .svg files and run:

import os
import cairosvg

for file in os.listdir('.'):
    name = file.split('.svg')[0]
    cairosvg.svg2png(url=name+'.svg',write_to=name+'.png') 

This will also ensure you don't overwrite your original .svg files, but will keep the same name. You can then move all your .png files to another directory with:

$ mv *.png [new directory]

crashed for me on windows 10: import cairocffi as cairo File "c:\program files (x86)\python35-32\lib\site-packages\cairocffi_init_.py", line 39, in cairo = dlopen(ffi, 'cairo', 'cairo-2', 'cairo-gobject-2', 'cairo.so.2') File "c:\program files (x86)\python35-32\lib\site-packages\cairocffi_init_.py", line 36, in dlopen raise OSError("dlopen() failed to load a library: %s" % ' / '.join(names)) OSError: dlopen() failed to load a library: cairo / cairo-2 / cairo-gobject-2 / cairo.so.2
Nice, cairosvg on Ubuntu-19.04 did the job for me.
I just wanted to write: What an excellent solution! The first PNGs looked great, but others didn't. Instead I have to write: It completely depends on the SVG which solution offers the best quality.
a
ampecs

why don't you give a try to inkscape command line, this is my bat file to convert all svg in this dir to png:

FOR %%x IN (*.svg) DO C:\Ink\App\Inkscape\inkscape.exe %%x -z --export-dpi=500 --export-area-drawing --export-png="%%~nx.png"


S
Shivam

This is what worked for me and would be the easiest to run.

find . -type f -name "*.svg" -exec bash -c 'rsvg-convert -h 1000  $0 > $0.png' {} \;
rename 's/svg\.png/png/' *

This will loop all the files in your current folder and sub folder and look for .svg files and will convert it to png with transparent background.

Make sure you have installed the librsvg and rename util

brew install librsvg
brew install rename

q
qubodup

Transparent background, exported at target height/size using ImageMagick 7:

magick -background none -size x1080 in.svg out.png

One-liner mass converter:

for i in *svg; do magick -background none -size x1080 "$i" "${i%svg}png"; done

I'm surprised this answer is so low. Some of the other approaches drew my complicated SVG incorrectly, but this worked perfectly.
I had to use convert, but otherwise it worked perfectly (convert -background none -size x1080 in.svg out.png).
Q
Qohelet

I came to this post - but I just wanted to do the conversion by batch and quick without the usage of any parameters (due to several files with different sizes).

rsvg drawing.svg drawing.png

For me the requirements were probably a bit easier than for the original author. (Wanted to use SVGs in MS PowerPoint, but it doesn't allow)


For reference, on macOS this is installed with brew install librsvg and the conversion command is rsvg-convert.
in Ubutni it is rsvg-convert too,package is librsvg2-bin and the output needs -o drawing.png
C
Community

Without librsvg, you may get a black png/jpeg image. We have to install librsvg to convert svg file with imagemagick.

Ubuntu

 sudo apt-get install imagemagick librsvg
 convert -density 1200 test.svg test.png

MacOS

 brew install imagemagick librsvg
 convert -density 1200 test.svg test.png


I don't have this library installed and I don't get black images either.
N
Nick

One thing that just bit me was setting the -density AFTER the input file name. That didn't work. Moving it to the first option in convert (before anything else) made it work (for me, YMMV, etc).


s
sbkm

On Linux with Inkscape 1.0 to convert from svg to png need to use

inkscape -w 1024 -h 1024 input.svg --export-file output.png

not

inkscape -w 1024 -h 1024 input.svg --export-filename output.png

Y
Yanone

I've solved this issue through changing the width and height attributes of the <svg> tag to match my intended output size and then converting it using ImageMagick. Works like a charm.

Here's my Python code, a function that will return the JPG file's content:

import gzip, re, os
from ynlib.files import ReadFromFile, WriteToFile
from ynlib.system import Execute
from xml.dom.minidom import parse, parseString


def SVGToJPGInMemory(svgPath, newWidth, backgroundColor):

    tempPath = os.path.join(self.rootFolder, 'data')
    fileNameRoot = 'temp_' + str(image.getID())

    if svgPath.lower().endswith('svgz'):
        svg = gzip.open(svgPath, 'rb').read()
    else:
        svg = ReadFromFile(svgPath)

    xmldoc = parseString(svg)

    width = float(xmldoc.getElementsByTagName("svg")[0].attributes['width'].value.split('px')[0])
    height = float(xmldoc.getElementsByTagName("svg")[0].attributes['height'].value.split('px')[0])

    newHeight = int(newWidth / width * height) 

    xmldoc.getElementsByTagName("svg")[0].attributes['width'].value = '%spx' % newWidth
    xmldoc.getElementsByTagName("svg")[0].attributes['height'].value = '%spx' % newHeight

    WriteToFile(os.path.join(tempPath, fileNameRoot + '.svg'), xmldoc.toxml())
    Execute('convert -background "%s" %s %s' % (backgroundColor, os.path.join(tempPath, fileNameRoot + '.svg'), os.path.join(tempPath, fileNameRoot + '.jpg')))

    jpg = open(os.path.join(tempPath, fileNameRoot + '.jpg'), 'rb').read()

    os.remove(os.path.join(tempPath, fileNameRoot + '.jpg'))
    os.remove(os.path.join(tempPath, fileNameRoot + '.svg'))

    return jpg

why would you return a computer generated image as jpeg :(?
J
James L.

https://i.stack.imgur.com/RTFHn.png

https://i.stack.imgur.com/Q7fxS.png

So instead I opened up Inkscape, then went to File, Export as PNG fileand a GUI box popped up that allowed me to set the exact dimensions I needed.

Version on Ubuntu 16.04 Linux: Inkscape 0.91 (September 2016)

(This image is from Kenney.nl's asset packs by the way)


S
SMAG

I was getting "low poly" curves using the general approach of increasing the density. So I decided to dig a little deeper and solve that problem as it seemed to be a side effect of this approach and I think it has to do with the original density or dpi.

We have seen 72 in this answer and 96 in this answer being suggested as the default density of an image, but which one? what if mine is different?

ImageMagick has a way to sort that out:

identify -verbose test.svg

this will put out a lot of metadata about the image file, including:

Image:
  Filename: test.svg
  Format: SVG (Scalable Vector Graphics)
  Mime type: image/svg+xml
  Class: ...
  Geometry: ...
  Resolution: 37.79x37.79
  Print size: ...
  Units: PixelsPerCentimeter
  # and a whole lot MORE ...

for a more concise query you can try:

identify -format "%x x %y %U" test.svg
=> 37.789999999999999147 x 37.789999999999999147 PixelsPerCentimeter

as suggested by this forum post and modified with this documentation

Now we know the current density of the image but may need to convert it to the correct units for conversion or mogrifying (PixelsPerInch or dpi)

this is a simple calculations of PixelsPerCentimeter x 2.54

37.789999999999999147 x 2.54 = 95.9866 ~> 96

if you prefer a chart or online calculator for this you can try https://www.pixelto.net/cm-to-px-converter.

now that we have the right original density converted to dpi, the rest of the logic stated in the above answers falls into place and the svg file can be scaled to a better "resolution" by multiplying the original density.

the original density was far too pixelated as a png for me, so in my case 5x the original density or -density 480 was good enough for me. Remember that this resizes the image as well and you will need to adjust for that when using / implementing the image as compared to the original svg.

NOTE: I did try the Inkscape approaches as well and also had the pixelation problem, but had already seen an improvement with the density approach so I decided to dig into that deeper. The output of the Inkscape attempt however gave me the idea, which you can also use for determining the dpi, but that is a lot to install just to get something you can already get with ImageMagick

Area 0:0:20.75:17 exported to 21 x 17 pixels (96 dpi)

关注公众号,不定期副业成功案例分享
Follow WeChat

Success story sharing

Want to stay one step ahead of the latest teleworks?

Subscribe Now