oc-resizer-plugin/compressors/PngCompressor.php

<?php

namespace Aweos\Resizer\Compressors;

use Illuminate\Support\Collection;
use Intervention\Image\ImageManager;
use Storage;

class PngCompressor extends Compressor {

    protected function getExtension(): string
    {
        return 'png';
    }

    public function make(string $path): array
    {
        $output = "/tmp/".str_slug(microtime());
        $mimetype = mime_content_type($path);

        system('imagemin '.escapeshellarg($path).' --plugin=pngquant > '.escapeshellarg($output));
        system("mv ".escapeshellarg($output)." ".escapeshellarg($path));

        return [
            $path => [$path],
        ];
    }

    public function shouldGenerateVersions(): bool
    {
        return true;
    }

    public function resize(string $source, string $destination, Collection $size): void
    {
        $extension = pathinfo($source, PATHINFO_EXTENSION);
        $temp = microtime().'.'.$extension;

        $r = app(ImageManager::class)->make($source);
        app(ImageManager::class)
            ->canvas($size->get('width'), $size->get('height'))->insert($r, 'center')
            ->save(Storage::path($temp));

        list($destWidth, $destHeight) = getimagesize(Storage::path($temp));

        $versionFilename = $destination.'/'.$this->versionFilename($source, $destWidth, $destHeight);

        if (Storage::exists($versionFilename)) {
            Storage::delete($versionFilename);
        }

        Storage::move($temp, $versionFilename);
    }

}