#!/usr/bin/perl

use strict;
use warnings;
use Image::Scale;

my $img = Image::Scale->new('image.gif');     
$img->resize_gd(  { width => 150 } );
$img->save_png('newImage.png');
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Image::Scale looks great. Can't get it to install though, because I don't have libjpeg and libpng on my XP vm. Working on it.

The problem is that Image::Resizer creates a new default image into which it resizes the original. It takes no account of the attributes--truecolor .v. palette; transparancy color etc.--of the original image.

It could (should) query these attributes of the original image and use them to create a compatible image before performing the copyResize(). Something like this (untested) might do the trick:

sub resize {
    my $self = shift;
    my ($width, $height, $constraint) = @_;
    unless ( defined $constraint ) { $constraint = 1; }
    unless ( $width && $height ) { croak "Image::Resize->resize(): usa
+ge error"; }

    if ( $constraint ) {
        my $k_h = $height / $self->height;
        my $k_w = $width / $self->width;
        my $k = ($k_h < $k_w ? $k_h : $k_w);
        $height = int($self->height * $k);
        $width  = int($self->width * $k);
    }

    my $image = GD::Image->new($width, $height, $self->truecolor ); ##
+ modified
    $image->transparent( $self->transparent() ); ## Added
    
    $image->copyResampled($self->gd,
        0, 0,               # (destX, destY)
        0, 0,               # (srcX,  srxY )
        $width, $height,    # (destX, destY)
        $self->width, $self->height
    );
    return $image;
}
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Thanks for the code. I tried it and perl tells me it can't locate methods "trueColor" and "transparent" ?!? I have no idea how that can be since these methods are part of GD::Image and all the other GD::Image methods work. Any ideas?

The modified lines should be:

    my $image = GD::Image->new($width, $height, $self->gd->truecolor )
+; 
    $image->transparent( $self->gd->transparent() );
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Still essentially untested. I haven't found an image with a transparent background kicking around.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

RIP an inspiration; A true Folk's Guy

Alternately, if you can call out to the shell, you could use imagemagick's "convert."

system("convert", "-resize", "file.gif", "newfile.gif");
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There are plenty of reasons you might not be able to or want to, but I thought I'd mention this just in case.

like pobocks says, imagemagick is an alternative. it's a very nice alternative if you ever need to do more, e.g. composite images, many more formats, add text/borders/effects. good fun, and quick.
the hardest line to type correctly is: stty erase ^H

I did have reasons not to use ImageMagick, but it works damn well. And pretty simply too. It is a heavyweight though.

It looks like Image::Resize makes a copy of the image with GD::copyResampled and there the transparency is lost. Unfortunately I don't know enough about GD to know how to fix it.