So, why do you expect things to work that way if you did not find the usage documented?

The next step is for you to read the documentation of Image::Resize and to change your code so it fits the documentation.

Your English description of what the two lines do is wrong - there is no line of code that is uploading an image. There is only a line that returns a filehandle of a file that was already uploaded to your server. You then use that filehandle as an argument to Image::Resize.

well. i think the image resize does't get my pic, i tried the Image Resize module locally without cgi and works

but with cgi script i get

Image::Resize->new(): file '02111.JPG' does not exist

#!/usr/bin/perl
use strict;
use warnings;
use CGI;
use File::Copy;
use CGI::Carp 'fatalsToBrowser';

my $q     = CGI->new;
my $photo = $q->param("pic");

if ($photo){
  my ($ext) = $photo =~ /([^.]+)$/;
  my $copydir = '/full/path/to/web/img/';
  my $image = Image::Resize->new($photo);
  my $gd = $image->resize(100, 100);
  my $newfile = $copydir."011190.$ext";
  my $upload_fh = $q->upload("pic");
  
  open OUTFILE,'>',$newfile or die "$!";
  print OUTFILE $gd->jpeg();
  binmode OUTFILE;
  while (<$upload_fh>){ 
    print OUTFILE;
  }
  close OUTFILE;
}


print << "HTM";
<h2>File upload</h2>
<form method="post" action="" enctype="multipart/form-data">
Filename: <input type="file" name="pic"/><br/><br/>
<input type="submit"/>
</form>
HTM
[download]

"well. i think the image resize does't get my pic"

You call Image::Resize->new before you've uploaded a file, passing the filename. In English, upload the file (covered in the CGI documentation), then resize your image.