Scan and automatically crop many images with SANE and ImageMagick

multiscan.pl

#!/usr/bin/perl

use strict;
use warnings;
use POSIX ":sys_wait_h";
STDOUT->flush();

use File::Which qw( which );

foreach ( qw| convert scanimage | ) {
        unless (which("$_")) {
                die "Missing dependency: $_\n";
        }
}

unless (scalar @ARGV) {
        die "Requires project name as argumunt\n";
}

my $base;
my $resume = 0;
foreach (@ARGV) {
        if ( $_ eq '-R' && !$resume ) {
                $resume = 1;
        } elsif (!defined($base)) {
                $base = $_;
        } else {
                die "Invalid or extraneous argument $_\n";
        }
}

if ( -d $base && !$resume ) {
        die "Directory $base already exists. Use -R to resume an existing project.\n";
} else {
        mkdir $base;
}

my @crops;
my $pid = 0;
my $ctr = 0;
if ($resume) {
        while (-e sprintf("$base/$base-%03d.jpeg",$ctr)) {
                $ctr++;
        }
        print "Resuming at $ctr\n.";
}
while ($ctr < 1000) {

        my $file = sprintf("$base-%03d.jpeg",$ctr);
        # Short delay just so that replace instruction follows after fork output
        sleep 1;
        print "Replace image then press Enter ('q' to finish) ";
        my $c = getc;
        if ($c eq 'q') {
                last;
        }
        print "\rScanning to $base/$file\n";
        #`cp carole-000.jpeg $file`;
        `scanimage --format jpeg --output $base/$file --progress --mode Color --resolution 600`;
        pipe(FROM_CHILD, TO_PARENT);
        my $newpid = fork;
        # Store all conversion pids
        if ($newpid) {
                close(TO_PARENT);
                push @crops, $newpid;
                $pid = $newpid;
        # Convert image on another thread while scanning next image
        } else {
                close(FROM_CHILD);
                # FAIL: cannot wait on sibling process, only child
                # If there's already a conversion thread going wait for it to finish.
                #if (scalar(@crops)) {
                #my $wait = pop @crops;
                #print "$$ waiting on $wait\n";
                #waitpid($wait, 0);
                #}
                my ($wh, $t) = split(' ',`convert $base/$file -blur 0x30 -fuzz 5% -trim info: | cut -d ' ' -f 3-4`);
                chomp $t;
                my ($w, $h) = split('x',$wh);
                my ($null, $x, $y) = split('\+',$t);
                $| = 1;
                print TO_PARENT "Cropping $base/$file in background width=$w height=$h x=$x y=$y \n";
                $w -= 48;
                $h -= 48;
                `convert $base/$file -crop ${w}x${h}+${x}+${y} +repage $base/cropped-$file`;
                exit;
        }
        $ctr++;
}

print "Finishing auto-cropping...\n";

for (my $i = 0; $i < scalar(@crops); $i++) {
        waitpid($crops[$i], 0);
        print "Finished " . ($i+1) . " of " . scalar(@crops) . " (${crops[$i]})\n";
}

print "Done\n";
exit(0);