public function saveComposite($filename)
{
// Measure the image and create an image 32x32 pixels wider than the source
$ir = $this->img->measure();
$wi = Canvas::createTrueColor($ir->w + SPECTRUM_SIZE + 4, $ir->h + SPECTRUM_SIZE + 4);
// Draw the image into the new working image offset by 32x32 puxels
$srect = $this->img->measure();
$drect = $this->img->measure();
$drect->move(SPECTRUM_SIZE + 4, SPECTRUM_SIZE + 4);
$this->img->draw($wi, $drect, $srect);
$wi->drawLine(0, $drect->y - 2, $wi->width, $drect->y - 2, [255, 255, 255]);
$wi->drawLine($drect->x - 2, 0, $drect->x - 2, $wi->height, [255, 255, 255]);
$wi->drawFilledRect(0, 0, $drect->x - 4, $drect->y - 4, [64, 64, 64]);
$this->drawSpectrumX($wi, $this->xbuckets, $drect);
$this->drawSpectrumY($wi, $this->ybuckets, $drect);
// Save the working image
$wi->save($filename);
}
