framework/validators/ImageValidator.php
protected function validateValue($value)
    {
        $result = parent::validateValue($value);

        return empty($result) ? $this->validateImage($value) : $result;
    }
protected function validateValue($value)
    {
        $result = parent::validateValue($value);

        return empty($result) ? $this->validateImage($value) : $result;
    }
{@inheritdoc}