public function createImageWatermark($name, $content, $options = array())
    {
        list($config, $maxWidthInPixel, $maxHeightInPixel,
            $sizingPolicy, $verticalAlignment, $horizontalAlignment,
            $verticalOffsetInPixel, $horizontalOffsetInPixel) = $this->parseOptions(
            $options,
            'config',
            'maxWidthInPixel',
            'maxHeightInPixel',
            'sizingPolicy',
            'verticalAlignment',
            'horizontalAlignment',
            'verticalOffsetInPixel',
            'horizontalOffsetInPixel'
        );

        if (empty($name)) {
            throw new BceClientException("The parameter name "
                . "should NOT be null or empty string");
        }
        if (empty($content)) {
            throw new BceClientException("The parameter content "
                . "should NOT be null or empty string");
        }

        $body = array(
            'name' => $name,
            'content' => $content,
        );

        $size = array();
        if ($maxWidthInPixel !== null) {
            $size['maxWidthInPixel'] = $maxWidthInPixel;
        }
        if ($maxHeightInPixel !== null) {
            $size['maxHeightInPixel'] = $maxHeightInPixel;
        }
        if ($sizingPolicy !== null) {
            $size['sizingPolicy'] = $sizingPolicy;
        }
        if (count($size) > 0) {
            $body['size'] = $size;
        }

        $position = array();
        if ($verticalAlignment !== null) {
            $position['verticalAlignment'] = $verticalAlignment;
        }
        if ($horizontalAlignment !== null) {
            $position['horizontalAlignment'] = $horizontalAlignment;
        }
        if ($verticalOffsetInPixel !== null) {
            $position['verticalOffsetInPixel'] = $verticalOffsetInPixel;
        }
        if ($horizontalOffsetInPixel !== null) {
            $position['horizontalOffsetInPixel'] = $horizontalOffsetInPixel;
        }
        if (count($position) > 0) {
            $body['position'] = $position;
        }

        return $this->sendRequest(
            HttpMethod::POST,
            array(
                'config' => $config,
                'body' => json_encode($body, JSON_FORCE_OBJECT),
            ),
            "/watermark/image"
        );
    }