private function placeholderGIF($config): string
    {
        $width = $config['width'];
        $height = $config['height'];
        $color = $config['color'] ?? 'transparent';

        if ($width === 1 && $height === 1 && $color === 'transparent') {
            return 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
        }

        $imagineInstance = $this->createImagineInstance();
        
        if ($imagineInstance === null) {
            return '';
        }
        
        $palette = new \Imagine\Image\Palette\RGB();
        
        if ($color==='transparent') {
            $col = $palette->color('#000000', 0);
        } else {
            $col = $palette->color($color);
        }
        
        $image = $imagineInstance->create(new Box($width, $height), $col);
        $data = $image->get('gif');
        
        return 'data:image/gif;base64,' . base64_encode($data);
    }