Different output from converting SVG file provided via StringIO and filename

[dcunhas]

I was doing some conversions to figure out the Wand API and I noticed that when I provide the same SVG string two different ways, I get two different images.
My code is:

from wand.image import Image
import StringIO
import os


print os.environ['MAGICK_HOME']

svg = '<?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" xml:space="preserve" height="241"  width="386"><g xmlns="http://www.w3.org/2000/svg" fill="none" stroke="none" stroke-width="none" stroke-linecap="butt" stroke-linejoin="miter" stroke-miterlimit="10" stroke-dasharray="" stroke-dashoffset="0" font-family="sans-serif" font-weight="normal" font-size="12" text-anchor="start" mix-blend-mode="normal"><path d="M165.2135,102.5625c0,-8.99478 7.29171,-16.2865 16.2865,-16.2865c8.99478,0 16.2865,7.29171 16.2865,16.2865c0,8.99478 -7.29171,16.2865 -16.2865,16.2865c-8.99478,0 -16.2865,-7.29171 -16.2865,-16.2865z" fill="#808080" stroke="#ffff00" stroke-width="3" opacity="0.3"/></g></svg>'

st = StringIO.StringIO(svg)
st.seek(0)

with Image(filename='C:/Users/Sandeep/temp/test.svg', format='svg') as img:
    img.format='png'
    img.save(filename="C:/Users/Sandeep/temp/s.png")

with Image(file=st, format='svg') as img:
    img.format='png'
    img.save(filename="C:/Users/Sandeep/temp/t.png")

s.png and t.png (the two output files) show different images. Furthermore, they have different file sizes (s.png is 2.54 KB and t.png is 3.12 KB). I verified that the file contents are the same as the contents of the string above, so what's going on?

[emcconville]

Might have better luck at the ImageMagick community form. This is more of an IM issue than a Wand.

Also, Which version of IM & Wand are you using? I'm using Wand 0.4.3 & IM 6.9.3 with the sample code provided, and the resulting output of s.png & t.png match.

[dcunhas]

Thanks, I reposted this there.
I'm using Wand 0.4.3 and IM 6.9.4-Q16. Also, I'm on Windows in case that matters for some reason.

[emcconville]

Could you try the following commands?

convert test.svg s.png
cat test.svg | convert svg:-  t.png

I can't remember the windows version of the above :(

[pholica]

I probably hit the same issue I used the same image from description. The result is:

$ convert test.svg s.png
$ cat test.svg | convert svg:-  t.png
$ file s.png t.png
s.png: PNG image data, 362 x 226, 8-bit colormap, non-interlaced
t.png: PNG image data, 386 x 241, 8-bit colormap, non-interlaced

I have Fedora 25 x86_64 with ImageMagick and python3-wand versions:

ImageMagick-6.9.3.0-3.fc25.x86_64
python3-wand-0.4.4-1.fc25.noarch

I'm quite sure that this wasn't issue on Fedora 24, so I may try to find where was the change. But yes, it seems to be problem of Imagemagick.