Kirby 2's ImageMagick thumb driver implementation rewritten using Imagick API instead of shell exec commands.

im-api-thumb-driver.php

/**
 * ImageMagick Driver
 */
thumb::$drivers['im-api'] = function($thumb) {
  try {
    
    $img = new Imagick($thumb->root());
    $img = $img->coalesceImages();
  
    do {
      $img->stripImage();
      
      if($thumb->options['interlace']) {
        $img->setInterlaceScheme(Imagick::INTERLACE_PLANE);
      }
  
      if($thumb->options['grayscale']) {
        $frame->setImageColorspace(Imagick::COLORSPACE_GRAY);
      }
  
      $img->setImageCompressionQuality($thumb->options['quality']); 
    
      if($thumb->options['blur']) {
        $img->blurImage(0, $thumb->options['blur']);
      }
      
      if($thumb->options['crop']) {
      
        if(empty($thumb->options['height'])) {
          $thumb->options['height'] = $thumb->options['width'];
        }
        
        $img->resizeImage($thumb->options['width'], $thumb->options['height'], Imagick::FILTER_LANCZOS, 1);
        $img->setImageGravity(Imagick::GRAVITY_CENTER);
        $img->cropImage($thumb->options['width'], $thumb->options['height'], 0, 0);
        
      } else {
      
        $dimensions = clone $thumb->source->dimensions();
        $dimensions->fitWidthAndHeight($thumb->options['width'], $thumb->options['height'], $thumb->options['upscale']);
        $img->resizeImage($dimensions->width(), $dimensions->height(), Imagick::FILTER_LANCZOS, 1);
        
      }
    } while ($img->nextImage());
    
    $img = $img->deconstructImages();
    
    $img->writeImages($thumb->destination->root, true);
    $img->clear();
    $img->destroy();
    
  } catch(Exception $e) {
    $thumb->error = $e;
  }
  // OLD WAY USING SHELL EXEC
  // $command = array();
  // $command[] = isset($thumb->options['bin']) ? $thumb->options['bin'] : 'convert';
  // $command[] = '"' . $thumb->source->root() . '"';
  // $command[] = '-strip';
  // if($thumb->options['interlace']) {
  //   $command[] = '-interlace line';
  // }
  // if($thumb->source->extension() === 'gif') {
  //   $command[] = '-coalesce';
  // }
  // if($thumb->options['grayscale']) {
  //   $command[] = '-colorspace gray';
  // }
  // if($thumb->options['autoOrient']) {
  //   $command[] = '-auto-orient';
  // }
  // $command[] = '-resize';
  // if($thumb->options['crop']) {
  //   if(empty($thumb->options['height'])) {
  //     $thumb->options['height'] = $thumb->options['width'];
  //   }
  //   $command[] = $thumb->options['width'] . 'x' . $thumb->options['height'] . '^';
  //   $command[] = '-gravity Center -crop ' . $thumb->options['width'] . 'x' . $thumb->options['height'] . '+0+0';
  // } else {
  //   $dimensions = clone $thumb->source->dimensions();
  //   $dimensions->fitWidthAndHeight($thumb->options['width'], $thumb->options['height'], $thumb->options['upscale']);
  //   $command[] = $dimensions->width() . 'x' . $dimensions->height() . '!';
  // }
  // $command[] = '-quality ' . $thumb->options['quality'];
  // if($thumb->options['blur']) {
  //   $command[] = '-blur 0x' . $thumb->options['blurpx'];
  // }
  // $command[] = '-limit thread 1';
  // $command[] = '"' . $thumb->destination->root . '"';
  // exec(implode(' ', $command));
};