/usr/bin/imagen is in hevea 2.30-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137  | #! /bin/sh
LATEX=latex
DVIPS=dvips
GS=gs
COM=/tmp/imagen-com.$$
RESOLUTION=100 # resolution in dpi
CROP="-trim +repage "
EXTRA=" "
MARGIN="-bordercolor none -border 2 "
TOGIF="-background white -flatten -interlace Plane gif:-"
TOPNG="-interlace Plane -quality 90 png:-"
TOEXT=${TOPNG}
EXT=png
TODIR="."
SVG=false
RM="/bin/rm -f"
while true
do
    case $1 in
     -todir)
       shift
       TODIR="$1"
       mkdir -p ${TODIR} 2> /dev/null || :
       ;;
     -gif)
	TOEXT=${TOGIF}
        EXT=gif
        ;;
     -png)
        TOEXT=${TOPNG}
        EXT=png
        ;;
     -pnm)
        TOEXT="pnm:-"
        EXT=pnm
        ;;
     -svg)
        SVG=true
        ;;
     -quant)
        shift
        echo "Warning: option -quant deprecated" 1>&2
        ;;
    -extra)
        shift
        EXTRA="$1"
        ;;
    -mag)
        shift
	RESOLUTION="$( expr '(' "$1" '*' 100 '+' 999 ')' '/' 1000)"
        ;;
    -res)
        shift
        RESOLUTION="$1"
        ;;
    -t)
        shift
        TPAPER="-t $1"
        ;;
     -pdflatex|-pdf)
         LATEX=pdflatex
       ;;
    -raw)
       EXTRA=''
       MARGIN=''
       TOEXT="pnm:-"
      ;;
    *)
        break
        ;;
    esac
    shift
done
echo "RESOLUTION: $RESOLUTION"
case $1 in
  '')
   BASE=image
   ;;
  *)
   BASE=$1
  ;;
esac
NAME=${BASE}.image
trap "${RM} ${NAME}.dvi ${NAME}.pdf `basename ${NAME}.log` `basename ${NAME}.aux` head.tmp body.tmp ${COM} ; exit 2" 1 2 3 8 10 13 15
DVIPSOPTS="-Z $TPAPER"
GSOPTS="-q -dNOPAUSE -dBATCH -dNOPROMPT -sDEVICE=pngalpha \
	-r$RESOLUTION -dAutoRotatePages=/None \
        -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -dDOINTERPOLATE \
        -P- -dSAFER"
CONVERT="convert png:- ${CROP} ${EXTRA} ${MARGIN} ${TOEXT}"
echo ${CONVERT} > ${COM}
if [ "${TODIR}" = "." ]
then
  FINAL=${BASE}%03d.${EXT}
else
  FINAL=${TODIR}/${BASE}%03d.${EXT}
fi
test -f  ${NAME}.tex ||\
{ echo "Failure: no ${NAME}.tex file!" 2>&1 ; exit 2 ; }
${LATEX} ${NAME}.tex
NAMEDIR=`dirname ${NAME}`
if [ "${LATEX}" = "pdflatex" ]
then
  if [ ${NAMEDIR} != "." ]
  then
    mv `basename ${NAME}.pdf` ${NAME}.pdf
  fi
  cat ${NAME}.pdf
else
 if [ ${NAMEDIR} != "." ]
  then
    mv `basename ${NAME}.dvi` ${NAME}.dvi
  fi
  ${DVIPS} ${DVIPSOPTS} -o - ${NAME}.dvi
fi |\
${GS} ${GSOPTS} -sOutputFile="| sh ${COM} > ${FINAL}" -
if $SVG
then
  pdflatex  ${NAME}.tex
  if [ ${NAMEDIR} != "." ]
  then
    mv `basename ${NAME}.pdf` ${NAME}.pdf
  fi
  pdfcrop ${NAME}.pdf ${NAME}.crop.pdf
  pdf2svg ${NAME}.crop.pdf "${TODIR}/${BASE}%03d.svg" all
  ${RM} ${NAME}.crop.pdf
fi
${RM} ${COM} ${NAME}.dvi ${NAME}.pdf  head.tmp body.tmp
${RM} `basename ${NAME}.log` `basename ${NAME}.aux`
 |