You can use the createWindow method of the canvas also. This script detects and sizes the window and textbox automatically, just feed it a jpg image on the commandline.

#!/usr/bin/perl
use warnings;
use strict;
use Tk;
use Tk::JPEG;
use Image::Magick;

my $im = Image::Magick->new;
my $image = shift || '2uni2.jpg';
my ($width, $height, $size, $format) = $im->Ping($image); 

my $mw = MainWindow->new();

my $canv = $mw->Canvas(-bg => 'lightsteelblue',
     -relief => 'sunken',
     -width => $width,
     -height => $height)->pack(-expand => 1, -fill => 'both');

my $img = $mw->Photo(-file => $image );
$canv->createImage( 0, 0, -image => $img, -anchor => 'nw' );

my $text = $mw->Scrolled('Text', 
                -bg=>'white',
                -scrollbars=>'osoe',
                     );

my $textcontainer = $canv->createWindow(
    $width/2, $height/2,  # default anchor is center
   -window => $text,
   -width => $width -200,
   -height => $height-200,
   -state => 'normal');

$text->focus;

MainLoop();
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