#!/bin/sh
#
# flicker_cmp [options] image1 image2 ...
#
# Generate and display an animation of the images given with 1/2 second delay
# so that you can see and compare the very slight differences between the two
# images.  A label is added to the image so you know which image is which.
#
# OPTIONS
#    -d delay    the delay for each frame in centi-seconds (def = 50)
#    -r size     resize image to this size (pixels or percentage)
#    -s size     scale image to this size (pixels or percentage)
#
###
#
# Anthony Thyssen   5 September 2007
#
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;
}

resize=''
delay=50

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

  -d) shift; delay="$1" ;;    # animation delay
  -r) shift; resize="-resize $1" ;;   # resize image to this size
  -s) shift; resize="-scale $1" ;;   # scale image to this size

  -)  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

convert -label "%f" "$@" $resize miff:- |\
  montage - -geometry +0+0 -tile 1x1 -background none miff:- |\
    animate -dispose background -delay "$delay" -loop 0 -