div class="uk-placeholder uk-text-center" style="margin: 20px; height: 60%;">
                        预览
                    </div> -->
                    <div>
                        <img id="preview" src="/img/lena.png" style="max-width: 405px" alt="">
                    </div>
                </div>

                <div>
                    <div class="uk-text-warning uk-margin-small-bottom" style="text-align: left; margin-left: 20px;">
                        注意：LSB 只需要含水印图�