#!/bin/bash
#
# im_profile [option] input_image  output_profile_image
#
# Plot a profile of a horizontal grayscale image given. The center row
# of pixels will be extracted if multiple rows are present.
# Including a small copy of the input gradient image along the X axis
# of the profile graph.
#
# Options
#    -v      Generate a vertical profile through the image.
#    -s      generate a 150x100 thummbnail image (default 300x200 pixels)
#    -g      Draw the profile in green instead of red
#    -b      Draw the profile in blue instead of red
#
#  Example
#    magick -size 1x300 gradient: -rotate 90 -function ArcSin 1 miff:- |\
#       im_profile -
#
# See Also
#  im_histogram   draw methematical expression as two images
#  im_graph       draw a histogram mapping function of the given IM options
#
####
#
# WARNING: Input arguments are NOT tested for correctness.
# This script represents a security risk if used ONLINE.
# I accept no responsiblity for misuse. Use at own risk.
#
# Anthony Thyssen,  5 July 2008
#
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program
Usage() {                              # output the script comments as docs
  echo >&2 "$PROGNAME:" "$@"
  sed >&2 -n '/^###/q; /^#/!q; s/^#//; s/^ //; 3s/^/Usage: /; 2,$ p' \
          "$PROGDIR/$PROGNAME"
  exit 10;
}
Error() {                              # output the script comments as docs
  echo >&2 "$PROGNAME:" "$@"
  exit 10;
}

COLOR=red
while [  $# -gt 0 ]; do
  case "$1" in
  --help|--doc*)  Usage ;;   # Documentation

  -v) VERTICAL=true ;;  # generate a vertical profile though the image.
  -s) SMALLER=true ;;   # smaller 'thumbnail' profile
  -g) COLOR=green ;;    # graph color green
  -b) COLOR=blue ;;     # graph color blue


  -)  break ;;    # STDIN, end of user options
  --) shift; break ;;    # end of user options
  -*) Usage "Unknown option \"$1\"" ;;
  *)  break ;;           # end of user options
  esac
  shift   # next option
done

[ $# -eq 0 ] && Usage "Missing input_image"
[ $# -gt 2 ] && Usage "Too many arguments"

# Temporary working images (with auto-clean-up on exit)
input="/tmp/im_profile_$$.miff"
trap "rm -f $input; exit 0" 0
trap "exit 2" 1 2 3 15

# Read in and extract the row (column) to be profiled.
#
# Warning: as of IM v6.5.3-9 'gravity' meta-data is saved in MIFF: file format
# As such we need to turn it off before saving.
#
[ "$VERTICAL" ] && VERTICAL="-transpose"
magick -regard-warnings "$1" +repage $VERTICAL \
        -gravity center -crop 0x1+0+0 +repage \
        +gravity $input  2>/dev/null
[ "$?" -eq 0 ] || Error "Invalid Input Image \"$1\""
shift

if [ $# -eq 1 ]; then
  output="$1"                     # output image filename (or special format)
  shift
else
  output="show:"  # if not given, magick display it direct
fi

# Test if gnuplot is new enough
echo "set lmargin at screen 0" | gnuplot >/dev/null 2>&1
if [ $? -ne 0 ]; then
  Error "Gnuplot is too old"
fi

# ---------------------------------------------

# Work out and set the gnuplot image size....
size_w=300  rsize_h=15      #  300x200 image with 15 pixel gradient height
if [ "$SMALLER" ]; then
  size_w=150 rsize_h=10     #  150x100 image with 10 pixel gradient height
fi
size_h=`expr $size_w \* 2 / 3`  # auto-calc, -2 pixels for border

gsize_w=`expr $size_w - 2`            # gnuplot width, - 2 border
gsize_h=`expr $size_h - $rsize_h - 3` # gnuplot height, - 3 borders

# gnuplot terminal size (version dependant - Arrgghhhh)
# note gnuplot output size is +1 and needs to be trimmed.
gsize="`expr $gsize_w + 1`,`expr $gsize_h + 1`"
grange="`expr $gsize_w - 1`"    # 0 to $grange values input

# Gnuplot of a Level function
{ echo "set terminal png size $gsize"
  echo "set lmargin at screen 0"
  echo "set bmargin at screen 0"
  echo "set rmargin at screen 0.99999"  # include the range extremes
  echo "set tmargin at screen 0.99999"
  echo 'unset key'
  echo 'unset border'
  echo 'set format ""'
  [ "$COLOR" = 'red'   ] && style=1
  [ "$COLOR" = 'green' ] && style=2
  [ "$COLOR" = 'blue'  ] && style=3
  [ $size_w -eq 150 ] && echo 'set xtics ( 38, 74, 111 ) scale 4'
  [ $size_w -eq 300 ] && echo 'set xtics ( 75, 149, 224 ) scale 4'
  echo 'set ytics ( 0.25, 0.5, 0.75 ) scale 2'
  echo "set xrange [0:$grange]"
  echo "set yrange [0:1]"

  # Using Binary Output
  #echo -n 'plot "-" binary format="%ushort" endian=big'
  #echo    '  array='"${gsize_w}"' using ($1/65536) with lines'
  #magick "$input" -depth 16 -resize ${gsize_w}x1\! -endian MSB gray:-

  # Using TXT format (failing as txt: is outputting percentages!)
  #echo 'plot "-"  using 0:($3/65536) with lines ls '"$style"
  #magick "$input" -depth 16 -resize ${gsize_w}x1\! txt:- |\
  #  tail -n+2 | tr -sc '0-9\n' ' '

  # Using PGM format
  echo 'plot "-"  using 0:($1/65536) with lines ls '"$style"
  magick "$input" -depth 16 -resize ${gsize_w}x1\! \
          -compress none PGM:- |\
    tail -n+4 | tr -s ' ' '\012'
} |
  #cat; exit;  # DEBUGGING
  gnuplot |
  magick - -write info:fd:2 miff:- | magick display -; exit  # DEBUGGING
  magick "$input"  -resize ${gsize_w}x1\! -scale ${gsize_w}x${rsize_h}\! \
    \( - -trim +repage \) +swap -size ${gsize_w}x1 xc:black +size +swap \
    -append  -bordercolor black -border 1x1 \
    "$output"
    #-identify show: ; exit

[ -f "$output" ] && chmod 644 "$output"