(Perl + ImageMagick) Crop image into right/left side inside bash directly.

crop-image.sh

perl -e '
use strict;
use warnings;
use File::Basename;
my $SRCDIR = "ori02/";
my $OUTDIR = "out02/";
my $w = 1506;
my $h = 2160;
my $firstPageInCenter = 1;
my $leftPageX = 405;
my $rightPageX = $w + $leftPageX;
qx(mkdir -p $OUTDIR);
my $i = 0;
foreach my $oriFile (glob("${SRCDIR}/*.jpg")) {
  if ($firstPageInCenter && $i == 0) {
    my $pageNo0 = sprintf("%03d", $i++);
    my $pageX = $leftPageX + int($w / 2);
    qx(convert "$oriFile" -crop "${w}x${h}+${pageX}" "${OUTDIR}${pageNo0}.jpg");
    next;
  }
  my $basename = substr(basename($oriFile), 0, -4);
  my $pageNo0 = sprintf("%03d", $i++);
  my $pageNo1 = sprintf("%03d", $i++);
  qx(convert "$oriFile" -crop "${w}x${h}+${rightPageX}" "${OUTDIR}${pageNo0}.jpg");
  qx(convert "$oriFile" -crop "${w}x${h}+${leftPageX}" "${OUTDIR}${pageNo1}.jpg");
}
'