Question

我编写了一个程序来比较两个文件夹（每个文件有1000个文件）的图像文件和一些逻辑(see this SO question)。

执行它时，成功比较直到900张图像，但它会产生类似Use of uninitialized value within @tfiles2 in concatenation (.) or string at C:\dropbox\Image_Compare\image_magick.pl line 55（＃3）的错误。然后我得到一个像Perl Command Line Interpreter has stopped working这样的弹出错误，所以我关闭了程序。

我的代码如下：

#!/usr/bin/perl
 use Image::Magick;
 no warnings 'uninitialized';
 use warnings;
 use diagnostics;
#use strict;
 use List::Util qw(first);

    my $directory1="C:/dropbox/Image_Compare/folder1";
    opendir(DIR, $directory1) or die "couldn't open $directory1: $!\n";
    my @files1 = grep { (!/^\./) && -f "$directory1/$_" } readdir(DIR);
    closedir DIR;
    print @files1;
    print 'end of files1';
    my $directory2="C:/dropbox/Image_Compare/folder2";
    opendir(DIR, $directory2) or die "couldn't open $directory2: $!\n";
    my @files2= grep { (!/^\./) && -f "$directory2/$_" } readdir(DIR);
    closedir DIR;
    print @files2;
    print 'end of files2';
    print $files1[0];
    foreach my $fils2 (@files2)
    {
        $g1 = Image::Magick->new;
        $g2 = Image::Magick->new;
        $temp1 = $g1->Read( filename=>"C:/dropbox/Image_Compare/folder1/".$files1[0].""); 
        $temp1 = $g2->Read( filename=>"C:/dropbox/Image_Compare/folder2/".$fils2."");
        $g3 = $g1->Compare( image=>$g2, metric=>'AE' ); # compare
        $error1 = $g3->Get( 'error' );
        #print $error1;
        if ($error1 == '0') 
        {
            print "Matching image is:"; 
            print $fils2 . "\n"; 
            my $tdirectory2="C:/dropbox/Image_Compare/folder2";
            opendir(DIR, $tdirectory2) or die "couldn't open $directory2: $!\n";
            my @tfiles2 = grep { (!/^\./) && -f "$tdirectory2/$_" } readdir(DIR);
            closedir DIR;
            #my $index = firstidx { $_ eq'"' .$fils2.'"' } @tfiles2;
            my $index = first { $tfiles2[$_] eq $fils2} 0..$#tfiles2;
            #print $fils2;
            print $index;
            my $i=0;
            foreach my $fils1 (@files1)
            {
                print 'ganesh';
                print $files1[$i];
                print $tfiles2[$index];
                print 'gowtham'; print "<br />";
                #print @tfiles2;
                $g4 = Image::Magick->new;
                $g5 = Image::Magick->new;
                $temp2 = $g4->Read( filename=>"C:/dropbox/Image_Compare/folder1/".$files1[$i].""); 
                $temp2 = $g5->Read( filename=>"C:/dropbox/Image_Compare/folder2/".$tfiles2[$index]."");
                $g6 = $g4->Compare( image=>$g5, metric=>'AE' ); # compare
                $error2 = $g6->Get( 'error' );
                $i++;
                $index++;
                if ($error2 == '0') {}
                else {print "Image not matching:"; print $tfiles2[$index]; last;}
                #if ($i == '800') {last;}


            }
            last
        }
    }

任何人都可以帮忙，我在做错了。

文件夹1文件名：0025.bmp到1051.bmp;

文件夹2文件名：0000.bmp到1008.bmp;

由于内甚

Answer 1

我不知道哪条违规行，但其中一条很可能是候选人：

$temp2 = $g5->Read( filename=>"C:/dropbox/Image_Compare/folder2/".$tfiles2[$index]."");

或

else {print "Image not matching:"; print $tfiles2[$index]; last;}

请注意，无论是否在数组边界内，都要增加$index。你没有检查条件$index > $#tfiles，它应该打破循环。

您可能想断言两个输入数组都包含＆gt;＆gt; 900个元素，打印长度如print "length: ", scalar @array, "\n";。

您可以通过测试数组中元素的定义来测试undefined错误实际发生的索引：

if (not defined $tfiles[$index] or not defined $files1[$i]) {
   die "There was an undefined element at index=$index, i=$i";
}

但是，$i和$index之间的偏移是不变的（如my answer中所述），因此您不必实际携带两个变量。

一个简单的比较器子程序可以使您的代码更具可读性，从而有助于调试（参见procedural programming）。

# return true if matching, false otherwise.
sub compare_images {
   my ($file1, $file2) = @_;
   my $image1 = Image::Magick->new;
   $image1->Read(filename => $file1);
   my $image2 = Image::Magick->new;
   $image2->Read(filename => $file2);
   my $result = $image1->Compare(image => $image2, metric => 'AE')->Get('error');
   # free memory
   undef $image1;
   undef $image2;
   return 0 == $result;
}

称为

my $image_root = "C:/dropbox/Image_Compare";
my ($folder1, $folder2) = qw(folder1 folder2);
unless (compare_images("$image_root/$folder1/$files1[$i]", 
                       "$image_root/$folder2/$tfiles[$index]")) {
   print "Images not matching at index=$index, i=$i\n";
   print "filename: $tfiles[$index]\n";
   last;
}

你可以阅读你的目录，如

sub get_images_from_dir {
   my ($dirname) = @_;
   -d $dirname or die qq(The path "$dirname" doesn't point to a directory!);
   opendir my $dir => $dirname or die qq(Can't open "$dirname": $!);
   my @files = grep {!/^\./ and -f "$dirname/$_"} readdir $dir;
   closedir $dir;
   unless (@files) { die qq(There were no interesting files in "$dirname".) }
   return @files;
}

这些步骤使代码更具可读性，并且可以轻松插入支票。

在连接（。）中的XXXX内使用未初始化的值或在image_magick.pl第XX行使用字符串

1 个答案: