I'm working with ActivePerl build 810 on an XP box. I want to resize a large image so that it will fit on the screen, with a little resampling, and then show it in a Tk::Label. $imgfile and $imgwidth are the file containing the image and the width to resize it to. $display is the Tk::Photo that contains the on-screen image. My first go worked fine:

sub rerender {
  `i_view32.exe .\\$imgfile /resample=($imgwidth,) /aspectratio /convert=".\\disp.png"`;
  $display->configure(-file => 'disp.png');
}

This uses an external program (irfanview) to do the dirty work, saves the downsized image to a temp file, and then reads it into the Tk::Photo. Thinking it could be faster w/o writing and readign the temp file, I did this using the Image::Magick module:

sub rerender {
  my $image = Image::Magick->new();
  $image->Read($imgfile);
  $image->Resize(width => $imgwidth, height => $imgwidth * 1.5, filter => Box);
  my $blob = $image->ImageToBlob();
  $display->configure(-format => 'png', -data => encode_base64($blob));
}

Which also works, but takes twice as long as the first version. Where do you think the time being spent? How could the image be produced and displayed any faster?