ImageMagick won't show Ghostscipt as delegate - delegates

Question

Was trying to get ImageMagick to talk to Ghostscript using MacPorts in OSX Lion but it wouldn't have it. Used to have it working fine under Snow Leopard but something went amiss during Migration assistant.
Anyhow, have unstalled all of Mac Ports and am now trying using Homebrew
Have installed Homebrew, installed ImageMagick and then ghostscript. Imagemagick is working fine (using a php image script and MAMP) but Ghostscript is not converting PDF's to jpgs. I can see than 'gs' is not listed as a delegate of Imagemagick.
Here are some relevant Terminal dumps:
convert -list delegate
Path: /usr/local/Cellar/imagemagick/6.7.7-6/etc/ImageMagick/delegates.xml
Delegate Command
-------------------------------------------------------------------------------
blender => "blender" -b "%i" -F PNG -o "%o""\n"convert" -concatenate "%o*.png" "%o"
cdr => "uniconvertor" "%i" "%o.svg"; mv "%o.svg" "%o"
cgm => "ralcgm" -d ps -oC "%o" 2> "%Z"
dng:decode => "ufraw-batch" --silent --create-id=also --out-type=png --out-depth=16 "--output=%u.png" "%i"
dvi => "dvips" -q -o "%o" "%i"
epsps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
epspdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
fig => "fig2dev" -L ps "%i" "%o"
hpg => "hp2xx" -q -m eps -f `basename "%o"` "%i"; mv -f `basename "%o"` "%o"
hpgl => "if [ -e hp2xx -o -e /usr/bin/hp2xx ]; then hp2xx -q -m eps -f `basename "%o"` "%i"; mv -f `basename "%o"` "%o"; else echo "You need to install hp2xx to use HPGL files with ImageMagick."; exit 1; fi"
htm => "html2ps" -U -o "%o" "%i"
html => "html2ps" -U -o "%o" "%i"
https => "curl" -s -k -o "%o" "https:%M"
ilbm => "ilbmtoppm" "%i" > "%o"
man => "groff" -man -Tps "%i" > "%o"
miff "ffmpeg" -v -1 -i "%i" -vframes %S -vcodec pam -an -f rawvideo -y "%u.pam" 2> "%Z"
pdfeps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
pdfps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
plt => "echo" "set size 1.25,0.62; set terminal postscript portrait color solid; set output \'%o\'; load \'%i\'" > "%u";"gnuplot" "%u"
pnm "%o"
pov => "povray" "+i%i" -D0 "+o%o" +fn%q +w%w +h%h +a -q9 "-kfi%s" "-kff%n";"convert" -concatenate "%o*.png" "%o"
pseps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
pspdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
rgba "scanimage" -d "%i" > "%o"
scanx => "scanimage" > "%o"
shtml => "html2ps" -U -o "%o" "%i"
sid => "mrsidgeodecode" -if sid -i "%i" -of tif -o "%o" > "%u"
svg => "rsvg-convert" -o "%o" "%i"
tiffps "enscript" -o "%o" "%i"
wmf => "wmf2eps" -o "%o" "%i"
doms-imac:~ dom$ convert -list delegate | grep --color -E '(eps|pdf)'
epsps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
epspdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
hpg => "hp2xx" -q -m eps -f `basename "%o"` "%i"; mv -f `basename "%o"` "%o"
hpgl => "if [ -e hp2xx -o -e /usr/bin/hp2xx ]; then hp2xx -q -m eps -f `basename "%o"` "%i"; mv -f `basename "%o"` "%o"; else echo "You need to install hp2xx to use HPGL files with ImageMagick."; exit 1; fi"
pdfeps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
pdfps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
pseps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
pspdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
wmf => "wmf2eps" -o "%o" "%i"
convert -list configure
Path: /usr/local/Cellar/imagemagick/6.7.7-6/lib/ImageMagick/config/configure.xml
Name Value
-------------------------------------------------------------------------------
CC /usr/bin/clang
CFLAGS -D_THREAD_SAFE -D_THREAD_SAFE -pthread -Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.7 -Wall -D_THREAD_SAFE -pthread
CODER_PATH /usr/local/Cellar/imagemagick/6.7.7-6/lib/ImageMagick/modules-Q16/coders
CONFIGURE ./configure '--disable-osx-universal-binary' '--without-perl' '--prefix=/usr/local/Cellar/imagemagick/6.7.7-6' '--disable-dependency-tracking' '--enable-shared' '--disable-static' '--with-modules' '--without-magick-plus-plus' 'CC=/usr/bin/clang' 'CFLAGS=-Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.7' 'LDFLAGS=-L/usr/local/Cellar/gettext/0.18.1.1/lib -L/usr/local/lib -L/usr/X11/lib' 'CPPFLAGS=-I/usr/local/Cellar/gettext/0.18.1.1/include -isystem /usr/local/include -I/usr/X11/include' 'CXX=/usr/bin/clang++' 'CXXFLAGS=-Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.7'
CONFIGURE_PATH /usr/local/Cellar/imagemagick/6.7.7-6/etc/ImageMagick/
COPYRIGHT Copyright (C) 1999-2012 ImageMagick Studio LLC
CPPFLAGS -I/usr/local/Cellar/imagemagick/6.7.7-6/include/ImageMagick
CXX /usr/bin/clang++
CXXFLAGS -Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.7 -D_THREAD_SAFE -pthread
DEFS -DHAVE_CONFIG_H
DELEGATES bzlib fontconfig freetype jpeg jng jp2 lcms2 png tiff x11 xml zlib
DISTCHECK_CONFIG_FLAGS 'CC=/usr/bin/clang' 'CFLAGS=-Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.7' 'CPPFLAGS=-I/usr/local/Cellar/gettext/0.18.1.1/include -isystem /usr/local/include -I/usr/X11/include' 'CXX=/usr/bin/clang++' 'LDFLAGS=-L/usr/local/Cellar/gettext/0.18.1.1/lib -L/usr/local/lib -L/usr/X11/lib' --disable-deprecated --with-quantum-depth=16 --with-umem=no --with-autotrace=no --with-gslib=no --with-fontpath= --with-wmf=no --with-perl=no
DOCUMENTATION_PATH /usr/local/Cellar/imagemagick/6.7.7-6/share/doc/ImageMagick
EXEC-PREFIX /usr/local/Cellar/imagemagick/6.7.7-6
EXECUTABLE_PATH /usr/local/Cellar/imagemagick/6.7.7-6/bin
FEATURES OpenCL
FILTER_PATH /usr/local/Cellar/imagemagick/6.7.7-6/lib/ImageMagick/modules-Q16/filters
HOST x86_64-apple-darwin11.4.0
INCLUDE_PATH /usr/local/Cellar/imagemagick/6.7.7-6/include/ImageMagick
LDFLAGS -L/usr/local/Cellar/imagemagick/6.7.7-6/lib -L/usr/local/Cellar/gettext/0.18.1.1/lib -L/usr/local/lib -L/usr/X11/lib -L/usr/X11/lib
LIB_VERSION 0x677
LIB_VERSION_NUMBER 6,7,7,6
LIBRARY_PATH /usr/local/Cellar/imagemagick/6.7.7-6/lib/ImageMagick
LIBS -lMagickCore -llcms2 -ltiff -lfreetype -ljpeg -L/usr/X11/lib -lfontconfig -lXext -lSM -lICE -lX11 -lXt -lbz2 -lz -lm -Wl,-framework,OpenCL -lm -lpthread -lltdl
NAME ImageMagick
PCFLAGS
PREFIX /usr/local/Cellar/imagemagick/6.7.7-6
QuantumDepth 16
RELEASE_DATE 2012-08-08
SHARE_PATH /usr/local/Cellar/imagemagick/6.7.7-6/share/ImageMagick
SVN_REVISION 8165
TARGET_CPU x86_64
TARGET_OS darwin11.4.0
TARGET_VENDOR apple
VERSION 6.7.7
WEBSITE http://www.imagemagick.org
How do I force Ghostscript to be seen as a delegate by ImageMagick?
 

Answer 1

Well, in your listing coming from convert -list delegate there are the following six lines:
eps<=>ps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
eps<=>pdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
pdf<=>eps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
pdf<=>ps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pswrite" "-sOutputFile=%o" "-f%i"
ps<=>eps "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=epswrite" "-sOutputFile=%o" "-f%i"
ps<=>pdf "gs" -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "-sDEVICE=pdfwrite" "-sOutputFile=%o" "-f%i"
They all do mention "gs"...
However, you say you first installed ImageMagick and only then Ghostscript.
So ImageMagick could not find any Ghostscript during compile time, that's why it doesn't appear in convert -list configure | grep DELEG....
You should try and install in reverse order: first Ghostscript, then ImageMagick....

Answer 2

tl;dr
For latecomers, this is the short version of #Kurt Pfeifle's answer + comment section. Just run
brew update \
&& brew reinstall ghostscript \
&& brew reinstall imagemagick --with-ghostscript

Answer 3

Do you have multiple installations of ImageMagick's convert on your system (maybe because your MacPorts installation wasn't cleanly removed)? To find out, run this commandline (which uses Spotlight search):
mdfind convert 2>&1 | grep convert
Update your question with the full info coming from these commands:
which convert
convert -list configure
convert -version
otool -L $(which convert)
which gsx
which gsc
which gs
gs -version
otool -L $(which gs)