Here is another Perl implementation, this time using the GD module. I have to say that this is quite slow, at least for my purposes. This runs on Windows and Linux.

In this code I call a number of support routines, but I think it is clear what they do and so I leave replacement as an exercise for the reader.

sub thumbnail
  {
    my($dir,$src_name) = @_;

    my($target_width,$target_height,$minratio);

    # You will have to fetch suitable parameters here
    # in my software Attribute::get() assigns a value
    # to the passed variable.  You could have (for example)
    #
    #    $target_width = 100;
    Attribute::get("$dir/$src_name","thumb_file_width",
                                         \$target_width,1);
    Attribute::get("$dir/$src_name","thumb_file_height",
                                         \$target_height,1);
    Attribute::get("$dir/$src_name","thumb_file_minratio",
                                         \$minratio,1);
    $minratio = 9 if(!defined $minratio || $minratio < 1);

    my($x_scale,$y_scale);

    my $gd = GD::Image->new("$dir/$src_name");
    if(!defined $gd)
      {
        # Again a magic routine, you could replace
        # with carp()
        ::add_output("Failed to read image data from $dir/$src_name");
        return undef;
      }

    my($src_width,$src_height) = $gd->getBounds();

    if(!defined $target_width && !defined $target_height)
      {
        ::add_output("Resizize must define either width or height");
        return undef;
      }

    $target_width = int($src_width*$target_height/$src_height)
                 if(!defined $target_width || $target_width <= 0);
    $target_height = int($src_height*$target_width/$src_width)
                 if(!defined $target_height || $target_height <= 0);
    if($target_width <= 0 || $target_width >= 16000 || 
             $target_height <= 0 || $target_height >= 16000)
      {
        ::add_output("Cannot resize image to $target_width x $target_h
+eight");
        return undef;
      }
    if((($src_width*$src_height)/($target_width*$target_height)) < $mi
+nratio)
      {
        # The thumbnail image does not save enough space to be worth c
+reating
        return undef;
      }
    my $new_gd = GD::Image->new($target_width,
                                      $target_height);

    $new_gd->copyResampled($gd,0,0,0,0,
                               $target_width,$target_height,
                               $src_width,$src_height);
    # Now lets save it

    # I should keep a track of all the thumbnails 
    # and allocate new entries 
    # in order, but for the moment I will be a bit cruder
    my $target_filename = GenName::obtain("$dir/$src_name",
                                         "thumb",$dir);
    return undef
        if(!defined $target_filename);

    if(default_type() eq "gif")
      {
        my $fh = IO::File->new(">$dir/$target_filename");
        binmode $fh;
        print $fh $new_gd->gif();
        $fh->close();
      }
    else
      {
        ::add_output("Cannot yet produce thumbnail in ".
                    default_type()." format\n");
        return undef;
      }

    # We succeeded
    FileCounts::inc('thumb');
    ::set_hidden("$dir/$target_filename") 
                               if($::hide_wfolio);

    return $target_filename;
  }

[download]

In reply to Re: thumbnails generator by hawtin
in thread thumbnails generator by spx2

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.