src/Support/FileConverter.php
public static function getContent($image)
    {
        switch (true) {
            case self::isUrl($image):
                return self::getOnlineImageContent($image);
            case self::isImage($image):
                return file_get_contents($image);
            case self::isResource($image):
                return stream_get_contents($image);
            case self::isSplFileInfo($image):
                return file_get_contents($image->getRealPath());
            case self::isString($image):
                // When the image was String type, We just think it's a local image
                // And he does not exist
                throw new RuntimeException("file {$image} has not exist.");
            default:
                throw new RuntimeException('not support image type.');
        }
    }
public static function getContent($image)
    {
        switch (true) {
            case self::isUrl($image):
                return self::getOnlineImageContent($image);
            case self::isImage($image):
                return file_get_contents($image);
            case self::isResource($image):
                return stream_get_contents($image);
            case self::isSplFileInfo($image):
                return file_get_contents($image->getRealPath());
            case self::isString($image):
                // When the image was String type, We just think it's a local image
                // And he does not exist
                throw new RuntimeException("file {$image} has not exist.");
            default:
                throw new RuntimeException('not support image type.');
        }
    }
Get image Content, support url/file/SplFileInfo

@param  string|\SplFileInfo|Resource $image

@return string