http://www.perlmonks.org?node_id=681943


in reply to thumbnails generator

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; }