Unknown device: pngalpha

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prp
Posts: 2
Joined: 2011-07-23T06:12:51-07:00
Authentication code: 8675308

Unknown device: pngalpha

Post by prp »

I try to convert postscript document to png image.

Post script file was created using miktex 2.8 system by executing following commands:

latex from.tex
dvips -o from.ps from

from.tex has content:

Code: Select all

\documentclass{article}
\pagestyle{empty}
\begin{document}
$$a_2$$
 \end{document}
When I am trying execute command

convert from.ps to.png

I give this exeption:

convert from.ps to.png
Unknown device: pngalpha
START 0 1506960 203519 1421680 135948 true 604 4 <1>
END PROCS 2 1527056 216634 1421680 137332 true 602 4 <1>
gs_std_e.ps 4 1527056 219409 1421680 138716 true 601 4 <1>
gs_il1_e.ps 6 1527056 221560 1421680 138716 true 601 4 <1>
END FONTDIR/ENCS 6 1527056 221686 1421680 138716 true 601 4 <1>
Unknown device: pngalpha
START 511557 1598968 286236 1421680 139460 true 604 5 <2>
END PROCS 511559 1598968 296023 1421680 140844 true 602 5 <2>
gs_std_e.ps 511561 1619064 302102 1441776 145556 true 601 5 <2>
gs_il1_e.ps 511562 1619064 304253 1441776 145556 true 601 5 <2>
END FONTDIR/ENCS 511563 1619064 304379 1441776 145556 true 601 5 <2>
Unknown device: pngalpha
Unknown device: pngalpha
START 0 1506960 203519 1421680 135948 true 604 4 <1>
END PROCS 2 1527056 216634 1421680 137332 true 602 4 <1>
gs_std_e.ps 4 1527056 219409 1421680 138716 true 601 4 <1>
gs_il1_e.ps 5 1527056 221560 1421680 138716 true 601 4 <1>
END FONTDIR/ENCS 6 1527056 221686 1421680 138716 true 601 4 <1>
Unknown device: pngalpha
START 511594 1598968 286236 1421680 139460 true 604 5 <2>
END PROCS 511596 1598968 296023 1421680 140844 true 602 5 <2>
gs_std_e.ps 511598 1619064 302102 1441776 145556 true 601 5 <2>
gs_il1_e.ps 511599 1619064 304253 1441776 145556 true 601 5 <2>
END FONTDIR/ENCS 511600 1619064 304379 1441776 145556 true 601 5 <2>
Unknown device: pngalpha
convert: `%s': %s "C:/gs/gs7.00/bin/gswin32c.exe" -q -dQUIET -dPARANOIDSAFER -dB
ATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dEPSCrop -dAlignToPixels=0 -dGr
idFitTT=2 "-sDEVICE=pngalpha" -dTextAlphaBits=4 -dGraphicsAlphaBits=4 "-r72x72"
-g595x842 "-sOutputFile=C:/Users/We/AppData/Local/Temp/magick-ZhCixPPQ-26477984
" "-fC:/Users/We/AppData/Local/Temp/magick-pXvRIBbB" "-fC:/Users/We/AppData/Loca
l/Temp/magick-yXH1pJr8" @ error/ps.c/InvokePostscriptDelegate/191.
convert: `%s': %s "C:/gs/gs7.00/bin/gswin32c.exe" -q -dQUIET -dPARANOIDSAFER -dB
ATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dEPSCrop -dAlignToPixels=0 -dGr
idFitTT=2 "-sDEVICE=pngalpha" -dTextAlphaBits=4 -dGraphicsAlphaBits=4 "-r72x72"
-g595x842 "-sOutputFile=C:/Users/We/AppData/Local/Temp/magick-ZhCixPPQ-26477984
" "-fC:/Users/We/AppData/Local/Temp/magick-pXvRIBbB" "-fC:/Users/We/AppData/Loca
l/Temp/magick-yXH1pJr8" -c showpage @ error/ps.c/InvokePostscriptDelegate/191.
convert: Postscript delegate failed `from.ps': No such file or directory @ error
/ps.c/ReadPSImage/807.
convert: missing an image filename `to.png' @ error/convert.c/ConvertImageComman
d/3015.


In system was installed Ghostscript 7.0.
OS Windows 7 x86.

Thanks for any help.
User avatar
anthony
Posts: 8883
Joined: 2004-05-31T19:27:03-07:00
Authentication code: 8675308
Location: Brisbane, Australia

Re: Unknown device: pngalpha

Post by anthony »

your Ghostscript was not compiled with that specific device. It is a ghostscript configuration item.
Anthony Thyssen -- Webmaster for ImageMagick Example Pages
https://imagemagick.org/Usage/
prp
Posts: 2
Joined: 2011-07-23T06:12:51-07:00
Authentication code: 8675308

Re: Unknown device: pngalpha

Post by prp »

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