convert resize VS perlMagick resize

[CptFantastic]

I'm busy setting up a web site.
I'd like to allow upuloading pictures. But to save the disk space I want to resize the pictures
to have only picture 640x480.

Please find here included a test script about resizing.
My problem is : I can use convert from withing that script and it gives a clear sharp image.
but all the different possibilities of perlMagick Resize are just giving a blurred image.

But if I'm using perl it not in the intention to use a system command to do what the perl module
is supposed to allow me to do.

Is there something wrong whith this option ?

(I also include a test image).

Thanks a lot for help.

Marc GREEN



Here is my code :

Code: Select all

#!/usr/bin/perl -w
#
# Nom :    upload_galerie_multi.plx
# But :      Galerie(s) photo(s) programme pour uploader
# Ecrit par :   Marc GREEN
# Date création : 20/02/2007  Version : 0.1
# Génération de la page (élémmentaire) par CGI
# Version/revision :
#
# use Carp;
use CGI qw/:standard/;

#
# The purpose of the pragma is to prohibit unsafe use of variables, symbolic
#   references and barewords
# Before using a variable you'll need to declare it using  "my" keyword
use strict;

#
# Pour utilisation de imagemagick
#
use Image::Magick;
# use Image::Info qw(image_info);

my $image_tmp;
my $status;
my $width;
my $height;
my $size;
my $format;
my $x_scale;
my $x_size;
my $y_scale;
my $y_size;
my $scale;
my $new_x;
my $new_y;
my @filters;
my $filter;
my $blur;

$x_size = 100;
$y_size = 150;
my $image;
my $entry;
my @photos_disponibles;
# my %galeries_disponibles;
my $photo_a_reduire;
my $photo_in;
my $photo_out;
my $geometry;   # Pour redimensionnement des images

$image_tmp = Image::Magick->new();

@photos_disponibles = qx{ls *.jpg};
chomp @photos_disponibles;

@filters = qw{Point Box  Hermite Hanning Hamming Blackman Gaussian Triangle   Quadratic Cubic Catrom Mitchell Lanczos Bessel Sinc};

foreach ( @photos_disponibles ) {   
# For every picture in the list apply all possible filters
   foreach $filter (@filters){
        print "Traitement de $_\n";
        $image_tmp = Image::Magick->new();
        $status = $image_tmp->Read($_);
        if ( $status ) {
            print "Erreur de lecture : $status \n";
        }
        ($width, $height, $size, $format) =
                $image_tmp->Ping("$_");
        $x_scale = $x_size / $width;
        $y_scale = $y_size / $height;
        $scale = $x_scale;
        if ( $y_scale < $scale ) {
            $scale = $y_scale;
        }
        $new_x = int( $width * $scale + 0.5 );
        $new_y = int( $height * $scale + 0.5 );
# Here I make a thumbnail image (and it is sharp after writing to file)
        $status = $image_tmp->Scale( width=>$new_x, height=>$new_y);
        if ( $status ) {
            print "Apres_reduction : $status <br>\n";
        };
        print "\tEcriture de mini_$_\n";
        $status = $image_tmp->Write("mini_$_");
        if ( $status ) {
            print "Apres_enregistrement : $status <br>\n";
        }
# Getting the image information change the size depending if the image is horizontal or vertical
        if ( $width > $height ) {
            $geometry="640x480";
        }
        else {
            $geometry="480x640";   
        }
        # For every image with every filter try different "blur" values
        for  ($blur = 0.125; $blur <=4; $blur *= 2 ){
            $status = $image_tmp->Resize(geometry=>$geometry,filter=>$filter,blur=>$blur);
            if ( $status ) {
                print "Apres_reduction : $status <br>\n";
            };
            print "\tEcriture de mid_".$filter."_".$blur."_$_\n";
            $status = $image_tmp->Write("mid_".$filter."_".$blur."_$_");
            if ( $status ) {
                print "Apres_enregistrement : $status <br>\n";
            }
# Here none of the resize images are sharp ==> unusable.
        }       
   }
    ($photo_a_reduire = $_ ) =~ s/ /\ /g;
    print "Redution de $photo_a_reduire\n";
    `convert $photo_a_reduire -resize 640x480 converted_$photo_a_reduire`;
# This one gives a great quality image.

}

[twotone]

I'm having exactly the same result.

In my perl script if I resize like this:

Code: Select all

$image->Resize(geometry=>'720x486!');

The result is blurry. If I execute the system command

Code: Select all

$result = `convert $file -resize 720x486! $out_name`;

The resulting picture is sharp.

Why is perlmagick resize blurry?

[fmw42]

I suspect because the command line resize has been updated and the perl code not. see recent topics in the Developers forum about changes to resize and to distort SRT

[anthony]

They both should be using the same core library code, unless the perl magick is using a different IM library! Did you upgrade Perl Magick with ImageMagick?

the resize code itself has not changed for a VERY VERY long time. It was distort that changed dramatically and recently.