check picture height of 641 - 648 pixels

diff --git a/scripts/evolis-driver.pl b/scripts/evolis-driver.pl
index 5797688..00a7eea 100755 (executable)
--- a/scripts/evolis-driver.pl
+++ b/scripts/evolis-driver.pl
@@ -52,6 +52,10 @@ sub read_pbm {
        open(my $pbm, "pnmflip -rotate270 $path |");
        my $magic = <$pbm>; chomp $magic;
        my $size = <$pbm>; chomp $size;
+       my ($x_size,undef) = split(/\s/,$size,2);
+       if ( $x_size <= 640 || $x_size > 648 ) {
+               die "picture has to have 81 bytes in line line, so 641 - 648 pixels hight";
+       }
        my $bitmap;
        if ( $magic eq 'P4' ) { # portable bitmap
                local $/ = undef;