Pango - Slowness

[rotem]

Hello,

I'm using Pango to write arabic sentences over image but the problem that it is much slower than Label.

For example, each time I use label it takes 8 milliseconds and Pango takes 25 milliseconds.

Is there something to do about the speed?

BTW, I would rather use draw text than Pango or Label, so if you know any other way to write Arabic character with draw text it would be great.

Thank you

[snibgo]

In my IM experiments with Arabic text, the only correct rendering is with Pango.

[rotem]

oh, well do you know any way to scale up an image, or maybe create a vector?

What I'm looking to do is to create one image/vector with the Arabic sentence and then scale it up and down as I need to.

And one more thing is, how can I create stroke to text with Pango?

Thanks!

[snibgo]

You can write the Arabic text into an SVG file, then render that. Inkscape works fine for that. IM can tell Inkscape to scale to whatever size you want.

[rotem]

Ok, I can try that. Do you have an example for how to create svg file with pango?


What about the stroke, any ideas?

[snibgo]

Do you have an example for how to create svg file with pango?

No. But you can create one with a text editor. For example, paste this into a file called arabicSvg2.svg:

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<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   width="400px"
   height="200px"
   id="svg2"
   version="1.1">
  <g
     id="layer1">
    <text
       xml:space="preserve"
       style="fill:#000000;fill-opacity:1;stroke:none"
       x="100"
       y="100"
       id="text2816"><tspan
         id="tspan2818"
         >šŋĩβģő élève äëïöü صَوْرة سِحْر</tspan></text>
  </g>
</svg>

Here is a copy of that file: http://snibgo.com/imforums/arabicSvg2.svg

Then run this command:

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convert -verbose -density 400 arabicSvg2.svg -trim +repage arabicSvg2.png

If your SVG delegate is Inkscape, the result will be something like this:



SVG with Inkscape is much slower than Pango.

I don't know what "create stroke to text" means.

[rotem]

Thank you for the SVG example.

When I run the command you gave me I get:

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'inkscape' '/var/tmp/magick-57991dFioi5ZvgEps' --export-png='/var/tmp/magick-57991FCnP3PrpjFMj' --export-dpi='400,400' --export-background='rgb(0%,0%,0%)' --export-background-opacity='0' > '/var/tmp/magick-57991X06JGQLS2JSi' 2>&1
Fontconfig error: Cannot load default config file
Fontconfig error: Cannot load default config file
mvg:/var/tmp/magick-57991fbO4OlNaMKaq=>/var/tmp/magick-57991fbO4OlNaMKaq MVG 2222x1111 2222x1111+0+0 16-bit sRGB 337B 0.030u 0:00.029
1.svg MVG 2222x1111 2222x1111+0+0 16-bit sRGB 337B 0.010u 0:00.019
1.svg=>1.png MVG 2222x1111=>887x69 8-bit sRGB 11.3KB 0.010u 0:00.009

and this is the result image



am I doing something wrong?

(as for the stroke I mean the text stroke which can be added with the SVG)


--------------------------- UPDATE ------------------------------

I installed inkscape and now I get this message and an empty image

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'inkscape' '/var/tmp/magick-75838qR4kn1zwPs3J' --export-png='/var/tmp/magick-75838bSUH0TYvxEOD' --export-dpi='300,300' --export-background='rgb(100%,100%,100%)' --export-background-opacity='1' > '/var/tmp/magick-75838kkXJNVLcFAoy' 2>&1
/var/tmp/magick-75838bSUH0TYvxEOD PNG 1333x667 1333x667+0+0 8-bit sRGB 5.16KB 0.020u 0:00.019
1.svg SVG 1333x667 1333x667+0+0 8-bit sRGB 5.16KB 0.000u 0:00.009
1.svg=>1.png SVG 1333x667=>1x1 8-bit sRGB 2c 317B 0.000u 0:00.000
convert: geometry does not contain image `1.svg' @ warning/attribute.c/GetImageBoundingBox/247.

[snibgo]

In your result, each character is written separately, and in the wrong order (left to right), so something is wrong.

Fontconfig error: Cannot load default config file

So the problem may be in "fontconfig".

Yes, Inkscape will do text strokes. It does most of SVG 1.1.

[rotem]

Hey,

I managed to fix the fontconfig error but the output is still reversed...

What I couldn't figure out is how Pango and Inkscape are connected?

If I install Inkscape with `brew install inkscape` and now I get this message and an empty image file

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'inkscape' '/var/tmp/magick-75838qR4kn1zwPs3J' --export-png='/var/tmp/magick-75838bSUH0TYvxEOD' --export-dpi='300,300' --export-background='rgb(100%,100%,100%)' --export-background-opacity='1' > '/var/tmp/magick-75838kkXJNVLcFAoy' 2>&1
/var/tmp/magick-75838bSUH0TYvxEOD PNG 1333x667 1333x667+0+0 8-bit sRGB 5.16KB 0.020u 0:00.019
1.svg SVG 1333x667 1333x667+0+0 8-bit sRGB 5.16KB 0.000u 0:00.009
1.svg=>1.png SVG 1333x667=>1x1 8-bit sRGB 2c 317B 0.000u 0:00.000
convert: geometry does not contain image `1.svg' @ warning/attribute.c/GetImageBoundingBox/247.

if I remove the `-trim` I get an image with the right size but without any text inside it

[snibgo]

Inkscape doesn't use Pango. Pango doesn't use Inkscape.

Try running Inkscape without IM. Can it read your SVG? Does it show correctly?

[rotem]

I will try it in a sec.

Just one more question, can Inkscape with SVG create a good Arabic text like Pango make?

[snibgo]

I don't know. It will depend on the font. Try it and see.

[rotem]

Well, what font did you use to create the example you sent me?

[snibgo]

I didn't specify a font, so Inkscape chose one. It might be Times New Roman.

[rotem]

This is what I get when I run

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inkscape -z -e 1.png 1.svg

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(process:78596): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.
2016-05-23 23:28:34.329 inkscape[78596:5066113] *** WARNING: Method userSpaceScaleFactor in class NSView is deprecated on 10.7 and later. It should not be used in new applications. Use convertRectToBacking: instead.
Fontconfig error: Cannot load default config file
Fontconfig warning: ignoring UTF-8: not a valid region tag
Background RRGGBBAA: ffffff00
Area 0:0:400:200 exported to 400 x 200 pixels (90 dpi)
Bitmap saved as: 1.png

The file is in the right size but empty without any text.

What should I do?