LiipImagine Stroke filter

config.yml

liip_imagine:
#...
  filter_sets:
    FILTER_NAME:
      filters:
        # ...
        stroke: { color: "#FF0000", size: 5 }

services.yml

services:
    generalmedia.app_bundle.filter.stroke_filter:
      class: Generalmedia\AccrowinBundle\Filter\StrokeFilter
      arguments: ["@liip_imagine" ]
      tags:
        - { name: "liip_imagine.filter.loader", loader: "stroke" }

StrokeFilter.php

<?php

namespace Generalmedia\AppBundle\Filter;

use Imagine\Image\ImageInterface;
use Imagine\Image\ImagineInterface;
use Imagine\Image\Palette\RGB;
use Imagine\Image\Point;
use Liip\ImagineBundle\Imagine\Filter\Loader\LoaderInterface;

/**
 * Class StrokeFilter
 */
class StrokeFilter implements LoaderInterface
{
    /**
     * @var ImagineInterface
     */
    protected $imagine;


    public function __construct(ImagineInterface $imagine)
    {
        $this->imagine = $imagine;
    }

    /**
     * @see Liip\ImagineBundle\Imagine\Filter\Loader\LoaderInterface::load()
     *
     * @param \Imagine\Image\ImageInterface $image
     * @param array                         $options
     *
     * @return \Imagine\Image\ImageInterface
     */
    public function load(ImageInterface $image, array $options = [])
    {
        $options += [
            'color' => "#FFF",
            'size'  => '1',
        ];

        // Create a transparent image
        $rgb         = new RGB();
        $transparent = $rgb->color("#FFFFFF", 0);
        $size        = $image->getSize();
        $bordered    = $this->imagine->create($size, $transparent);

        $thickness   = $options["size"];
        $strokeColor = $rgb->color($options["color"]);

        // Corners coordinates
        $topLeft     = new Point(0, 0);
        $bottomLeft  = new Point(0, $size->getHeight());
        $topRight    = new Point($size->getWidth(), 0);
        $bottomRight = new Point($size->getWidth(), $size->getHeight());

        // Draw 4 lines in clockwise, starting from top
        $bordered->draw()->line($topLeft, $topRight, $strokeColor, $thickness);
        $bordered->draw()->line($topLeft, $bottomLeft, $strokeColor, $thickness);
        $bordered->draw()->line($bottomLeft, $bottomRight, $strokeColor, $thickness);
        $bordered->draw()->line($topRight, $bottomRight, $strokeColor, $thickness);

        return $image->paste($bordered, new Point(0, 0));
    }
}