图片去背景

别再花钱买PDF编辑器了！Mac“预览”App的12个隐藏绝技

周一下午三点，一封加急邮件躺在收件箱里：一份PDF合同，老板要求五分钟内签好字发回去。你的第一反应是什么？打开浏览器，搜索“PDF在线签名”，然后在几十个看起来不太安全的网站中犹豫不决，担心自己的签名和个人信息被泄露…… 其实，你完全不必如此狼狈。解药，一直就躺在你Mac的“应用程序”文件夹里。…
<script type="text/javascript" src="https://www.blogger.com/static/v1/widgets/2422103421-widgets.js"></script>
<script type='text/javascript'>
window['__wavt'] = 'AOuZoY5hBh7aAXZ1POnzpuiTLhE7sxlzwA:1755000903313';_WidgetManager._Init('//www.blogger.com/rearrange?blogID\x3d862577558267434976','//www.kejiciwei.com/search/label/%E5%9B%BE%E7%89%87%E5%8E%BB%E8%83%8C%E6%99%AF?hl\x3den','862577558267434976');
_WidgetManager._SetDataContext([{'name': 'blog', 'data': {'blogId': '862577558267434976', 'title': '\u79d1\u6280\u523a\u732c', 'url': 'https://www.kejiciwei.com/search/label/%E5%9B%BE%E7%89%87%E5%8E%BB%E8%83%8C%E6%99%AF?hl\x3den', 'canonicalUrl': 'https://www.kejiciwei.com/search/label/%E5%9B%BE%E7%89%87%E5%8E%BB%E8%83%8C%E6%99%AF', 'homepageUrl': 'https://www.kejiciwei.com/?hl\x3den', 'searchUrl': 'https://www.kejiciwei.com/search', 'canonicalHomepageUrl': 'https://www.kejiciwei.com/', 'blogspotFaviconUrl': 'https://www.kejiciwei.com/favicon.ico', 'bloggerUrl': 'https://www.blogger.com', 'hasCustomDomain': true, 'httpsEnabled': true, 'enabledCommentProfileImages': true, 'gPlusViewType': 'FILTERED_POSTMOD', 'adultContent': false, 'analyticsAccountNumber': '', 'encoding': 'UTF-8', 'locale': 'en', 'localeUnderscoreDelimited': 'en', 'languageDirection': 'ltr', 'isPrivate': false, 'isMobile': false, 'isMobileRequest': false, 'mobileClass': '', 'isPrivateBlog': false, 'isDynamicViewsAvailable': false, 'feedLinks': '', 'meTag': '', 'adsenseClientId': 'ca-pub-1683234937128959', 'adsenseHostId': 'ca-host-pub-1556223355139109', 'adsenseHasAds': true, 'adsenseAutoAds': true, 'boqCommentIframeForm': true, 'loginRedirectParam': '', 'view': '', 'dynamicViewsCommentsSrc': '//www.blogblog.com/dynamicviews/4224c15c4e7c9321/js/comments.js', 'dynamicViewsScriptSrc': '//www.blogblog.com/dynamicviews/f453485e1aff85d4', 'plusOneApiSrc': 'https://apis.google.com/js/platform.js', 'disableGComments': true, 'interstitialAccepted': false, 'sharing': {'platforms': [{'name': 'Get link', 'key': 'link', 'shareMessage': 'Get link', 'target': ''}, {'name': 'Facebook', 'key': 'facebook', 'shareMessage': 'Share to Facebook', 'target': 'facebook'}, {'name': 'BlogThis!', 'key': 'blogThis', 'shareMessage': 'BlogThis!', 'target': 'blog'}, {'name': 'X', 'key': 'twitter', 'shareMessage': 'Share to X', 'target': 'twitter'}, {'name': 'Pinterest', 'key': 'pinterest', 'shareMessage': 'Share to Pinterest', 'target': 'pinterest'}, {'name': 'Email', 'key': 'email', 'shareMessage': 'Email', 'target': 'email'}], 'disableGooglePlus': true, 'googlePlusShareButtonWidth': 0, 'googlePlusBootstrap': '\x3cscript type\x3d\x22text/javascript\x22\x3ewindow.___gcfg \x3d {\x27lang\x27: \x27en\x27};\x3c/script\x3e'}, 'hasCustomJumpLinkMessage': false, 'jumpLinkMessage': 'Read more', 'pageType': 'index', 'searchLabel': '\u56fe\u7247\u53bb\u80cc\u666f', 'pageName': '\u56fe\u7247\u53bb\u80cc\u666f', 'pageTitle': '\u79d1\u6280\u523a\u732c: \u56fe\u7247\u53bb\u80cc\u666f', 'metaDescription': ''}}, {'name': 'features', 'data': {}}, {'name': 'messages', 'data': {'edit': 'Edit', 'linkCopiedToClipboard': 'Link copied to clipboard!', 'ok': 'Ok', 'postLink': 'Post Link'}}, {'name': 'template', 'data': {'name': 'custom', 'localizedName': 'Custom', 'isResponsive': true, 'isAlternateRendering': false, 'isCustom': true}}, {'name': 'view', 'data': {'classic': {'name': 'classic', 'url': '?view\x3dclassic'}, 'flipcard': {'name': 'flipcard', 'url': '?view\x3dflipcard'}, 'magazine': {'name': 'magazine', 'url': '?view\x3dmagazine'}, 'mosaic': {'name': 'mosaic', 'url': '?view\x3dmosaic'}, 'sidebar': {'name': 'sidebar', 'url': '?view\x3dsidebar'}, 'snapshot': {'name': 'snapshot', 'url': '?view\x3dsnapshot'}, 'timeslide': {'name': 'timeslide', 'url': '?view\x3dtimeslide'}, 'isMobile': false, 'title': '\u79d1\u6280\u523a\u732c', 'description': '', 'url': 'https://www.kejiciwei.com/search/label/%E5%9B%BE%E7%89%87%E5%8E%BB%E8%83%8C%E6%99%AF?hl\x3den', 'type': 'feed', 'isSingleItem': false, 'isMultipleItems': true, 'isError': false, 'isPage': false, 'isPost': false, 'isHomepage': false, 'isArchive': false, 'isSearch': true, 'isLabelSearch': true, 'search': {'label': '\u56fe\u7247\u53bb\u80cc\u666f', 'resultsMessage': 'Showing posts with the label \u56fe\u7247\u53bb\u80cc\u666f', 'resultsMessageHtml': 'Showing posts with the label \x3cspan class\x3d\x27search-label\x27\x3e\u56fe\u7247\u53bb\u80cc\u666f\x3c/span\x3e'}}}, {'name': 'widgets', 'data': [{'title': '\u79d1\u6280\u523a\u732c (Header)', 'type': 'Header', 'sectionId': 'sec_Header_Title', 'id': 'Header01'}, {'title': '\u641c\u7d22', 'type': 'BlogSearch', 'sectionId': 'sec_Header_Search', 'id': 'BlogSearch01'}, {'title': 'Header Icon', 'type': 'TextList', 'sectionId': 'sec_Header_Icon', 'id': 'TextList01'}, {'title': 'Bookmark Posts', 'type': 'LinkList', 'sectionId': 'sec_Header_Icon', 'id': 'LinkList02'}, {'title': 'Translate\uff0c\u591a\u8bed\u8a00', 'type': 'LinkList', 'sectionId': 'sec_Header_Icon', 'id': 'LinkList03'}, {'title': 'Navigation Menu', 'type': 'HTML', 'sectionId': 'sec_Nav_Widgets_1', 'id': 'HTML01'}, {'title': 'Additional Links', 'type': 'PageList', 'sectionId': 'sec_Nav_Widgets_2', 'id': 'PageList02'}, {'title': 'Social Links', 'type': 'LinkList', 'sectionId': 'sec_Nav_Widgets_2', 'id': 'LinkList04'}, {'title': 'Labels Description\u5217\u8868\u9875\u7f51\u7ad9\u63cf\u8ff0', 'type': 'LinkList', 'sectionId': 'sec_Under_Header', 'id': 'LinkList07'}, {'title': '\u7cbe\u9009', 'type': 'FeaturedPost', 'sectionId': 'sec_Top_Widgets', 'id': 'FeaturedPost01', 'postId': '5547678303592747614'}, {'title': 'Blog Posts', 'type': 'Blog', 'sectionId': 'sec_Main_Widgets', 'id': 'Blog01', 'posts': [{'id': '5353590642777432242', 'title': '\u522b\u518d\u82b1\u94b1\u4e70PDF\u7f16\u8f91\u5668\u4e86\uff01Mac\u201c\u9884\u89c8\u201dApp\u768412\u4e2a\u9690\u85cf\u7edd\u6280', 'featuredImage': 'https://blogger.googleusercontent.com/img/a/AVvXsEirLVAByi9fzxpEk7NPQ-vXD73YQ0R9Lted1SYQH1YdlCjY9Nsj61vL-z5SWDcjVdb6MV13Zu6-QZXWLw-StuPnTXvmwDJOkRO012h4npT6bK8yR7jaG5hldM0Hcrwe-i_azW8zv6-hHIPsTQRoCzrJCynCQScyopFMtVsCOQ79nD3DE41RnHOyJNpk_H5u', 'showInlineAds': false}], 'footerBylines': [{'regionName': 'footer1', 'items': [{'name': 'author', 'label': 'Published by'}, {'name': 'timestamp', 'label': 'On'}, {'name': 'comments', 'label': 'Comment'}, {'name': 'icons', 'label': ''}, {'name': 'share', 'label': ''}]}, {'regionName': 'footer2', 'items': [{'name': 'labels', 'label': 'in'}]}, {'regionName': 'footer3', 'items': [{'name': 'location', 'label': 'Location:'}]}], 'allBylineItems': [{'name': 'author', 'label': 'Published by'}, {'name': 'timestamp', 'label': 'On'}, {'name': 'comments', 'label': 'Comment'}, {'name': 'icons', 'label': ''}, {'name': 'share', 'label': ''}, {'name': 'labels', 'label': 'in'}, {'name': 'location', 'label': 'Location:'}]}, {'title': 'Table of contents', 'type': 'HTML', 'sectionId': 'sec_Main_Widgets', 'id': 'HTML11'}, {'title': '\u70ed\u95e8', 'type': 'PopularPosts', 'sectionId': 'sec_Side_Widgets', 'id': 'PopularPosts01', 'posts': [{'title': '\u5982\u4f55\u7528iPhone\u81ea\u5e26\u5929\u6c14\u5e94\u7528\uff0c\u8f7b\u677e\u638c\u63e1\u53f0\u98ce\u548c\u964d\u96e8\u9884\u8b66\uff01', 'id': 7824000275425797403}, {'title': 'iPhone 16 \u4fa7\u8fb9\u6309\u94ae\uff1a\u529f\u80fd\u3001\u8bbe\u7f6e\u4e0e\u6545\u969c\u6392\u9664\u6307\u5357', 'id': 6324657534951600404}, {'title': '\u5982\u4f55\u5728iPhone16ProMax\u7167\u7247\u4e2d\u79fb\u9664\u4e0d\u5fc5\u8981\u7684\u7269\u4f53\u6216\u4eba\u7269\uff1a\u5b8c\u6574\u6559\u5b66\u6307\u5357', 'id': 3737386250663345191}, {'title': 'iOS 26 \u5b9e\u7528\u5c0f\u6280\u5de7\uff0c\u8ba9\u4f60\u7684 iPhone \u66f4\u987a\u624b\uff01', 'id': 4582138411542718594}, {'title': '\u5982\u4f55\u5c06\u5c0f\u7ec4\u4ef6\u6dfb\u52a0\u5230\u60a8\u7684iPhone\u4e3b\u5c4f\u5e55', 'id': 875791422767497974}]}, {'title': 'Labels', 'type': 'Label', 'sectionId': 'sec_Side_Widgets', 'id': 'Label01'}, {'title': 'Take me back', 'type': 'HTML', 'sectionId': 'sec_Error_404', 'id': 'HTML404'}, {'title': 'Organization [BlogTitle] \u9875\u811aslogan', 'type': 'Image', 'sectionId': 'sec_Footer_Organization', 'id': 'Image21'}, {'title': 'Social Media Links', 'type': 'LinkList', 'sectionId': 'sec_Footer_Organization', 'id': 'LinkList21'}, {'title': 'Product', 'type': 'LinkList', 'sectionId': 'sec_Footer_Widgets', 'id': 'LinkList22'}, {'title': 'Resources', 'type': 'LinkList', 'sectionId': 'sec_Footer_Widgets', 'id': 'LinkList23'}, {'title': 'Support', 'type': 'LinkList', 'sectionId': 'sec_Footer_Widgets', 'id': 'LinkList24'}, {'title': 'Company', 'type': 'LinkList', 'sectionId': 'sec_Footer_Widgets', 'id': 'LinkList25'}, {'title': 'Credit \u7248\u6743\u4fe1\u606f', 'type': 'HTML', 'sectionId': 'sec_Footer_Bottom', 'id': 'HTML21'}, {'title': 'Mobile Menu', 'type': 'TextList', 'sectionId': 'sec_Mobile_Menu', 'id': 'TextList99'}, {'title': 'Labels', 'type': 'Label', 'sectionId': 'sec_Theme_Hidden', 'id': 'Label41'}, {'title': '\u09af\u09cb\u0997\u09be\u09af\u09cb\u0997 \u09ab\u09b0\u09cd\u09ae', 'type': 'ContactForm', 'sectionId': 'sec_Theme_Hidden', 'id': 'ContactForm41'}, {'title': 'Pageviews last month', 'type': 'Stats', 'sectionId': 'sec_Theme_Hidden', 'id': 'Stats41'}, {'title': 'Firebase Configurations', 'type': 'LinkList', 'sectionId': 'sec_Addon_Widgets', 'id': 'LinkList61'}, {'title': 'Progressive Web App', 'type': 'LinkList', 'sectionId': 'sec_Addon_Widgets', 'id': 'LinkList62'}, {'title': 'Cookie Consent [NoTitle]', 'type': 'LinkList', 'sectionId': 'sec_Addon_Widgets', 'id': 'LinkList63'}, {'title': 'Image Uploader', 'type': 'Image', 'sectionId': 'sec_Addon_Widgets', 'id': 'Image61'}]}]);
_WidgetManager._RegisterWidget('_HeaderView', new _WidgetInfo('Header01', 'sec_Header_Title', document.getElementById('Header01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_BlogSearchView', new _WidgetInfo('BlogSearch01', 'sec_Header_Search', document.getElementById('BlogSearch01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_TextListView', new _WidgetInfo('TextList01', 'sec_Header_Icon', document.getElementById('TextList01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList02', 'sec_Header_Icon', document.getElementById('LinkList02'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList03', 'sec_Header_Icon', document.getElementById('LinkList03'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_HTMLView', new _WidgetInfo('HTML01', 'sec_Nav_Widgets_1', document.getElementById('HTML01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_PageListView', new _WidgetInfo('PageList02', 'sec_Nav_Widgets_2', document.getElementById('PageList02'), {'title': 'Additional Links', 'links': [{'isCurrentPage': false, 'href': '/p/sitemap.xml', 'title': 'Sitemap'}, {'isCurrentPage': false, 'href': '#', 'title': 'Disclaimer'}, {'isCurrentPage': false, 'href': '#', 'title': 'Privacy'}], 'mobile': false, 'showPlaceholder': true, 'hasCurrentPage': false}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList04', 'sec_Nav_Widgets_2', document.getElementById('LinkList04'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList07', 'sec_Under_Header', document.getElementById('LinkList07'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_FeaturedPostView', new _WidgetInfo('FeaturedPost01', 'sec_Top_Widgets', document.getElementById('FeaturedPost01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_BlogView', new _WidgetInfo('Blog01', 'sec_Main_Widgets', document.getElementById('Blog01'), {'cmtInteractionsEnabled': false, 'navMessage': 'Showing posts with label \x3cb\x3e\u56fe\u7247\u53bb\u80cc\u666f\x3c/b\x3e. \x3ca href\x3d\x22https://www.kejiciwei.com/\x22\x3eShow all posts\x3c/a\x3e', 'lightboxEnabled': true, 'lightboxModuleUrl': 'https://www.blogger.com/static/v1/jsbin/497930099-lbx.js', 'lightboxCssUrl': 'https://www.blogger.com/static/v1/v-css/123180807-lightbox_bundle.css'}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_HTMLView', new _WidgetInfo('HTML11', 'sec_Main_Widgets', document.getElementById('HTML11'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_PopularPostsView', new _WidgetInfo('PopularPosts01', 'sec_Side_Widgets', document.getElementById('PopularPosts01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LabelView', new _WidgetInfo('Label01', 'sec_Side_Widgets', document.getElementById('Label01'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_HTMLView', new _WidgetInfo('HTML404', 'sec_Error_404', document.getElementById('HTML404'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_ImageView', new _WidgetInfo('Image21', 'sec_Footer_Organization', document.getElementById('Image21'), {'resize': true}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList21', 'sec_Footer_Organization', document.getElementById('LinkList21'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList22', 'sec_Footer_Widgets', document.getElementById('LinkList22'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList23', 'sec_Footer_Widgets', document.getElementById('LinkList23'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList24', 'sec_Footer_Widgets', document.getElementById('LinkList24'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList25', 'sec_Footer_Widgets', document.getElementById('LinkList25'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_HTMLView', new _WidgetInfo('HTML21', 'sec_Footer_Bottom', document.getElementById('HTML21'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_TextListView', new _WidgetInfo('TextList99', 'sec_Mobile_Menu', document.getElementById('TextList99'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LabelView', new _WidgetInfo('Label41', 'sec_Theme_Hidden', document.getElementById('Label41'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_ContactFormView', new _WidgetInfo('ContactForm41', 'sec_Theme_Hidden', document.getElementById('ContactForm41'), {'contactFormMessageSendingMsg': 'Sending...', 'contactFormMessageSentMsg': 'Your message has been sent.', 'contactFormMessageNotSentMsg': 'Message could not be sent. Please try again later.', 'contactFormInvalidEmailMsg': 'A valid email address is required.', 'contactFormEmptyMessageMsg': 'Message field cannot be empty.', 'title': '\u09af\u09cb\u0997\u09be\u09af\u09cb\u0997 \u09ab\u09b0\u09cd\u09ae', 'blogId': '862577558267434976', 'contactFormNameMsg': 'Name', 'contactFormEmailMsg': 'Email', 'contactFormMessageMsg': 'Message', 'contactFormSendMsg': 'Send', 'contactFormToken': 'AOuZoY4cXkFBND-vYSEN9tDcp-YhBHDNbQ:1755000903313', 'submitUrl': 'https://www.blogger.com/contact-form.do'}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_StatsView', new _WidgetInfo('Stats41', 'sec_Theme_Hidden', document.getElementById('Stats41'), {'title': 'Pageviews last month', 'showGraphicalCounter': false, 'showAnimatedCounter': false, 'showSparkline': true, 'statsUrl': '//www.kejiciwei.com/b/stats?hl\x3den\x26style\x3dBLACK_TRANSPARENT\x26timeRange\x3dLAST_WEEK\x26token\x3dAPq4FmBBcbNK1tKcKuB6AxQSil3PL5F_2Afo4xQg2G12AlwGELsXUGfHXnn34DQB5BAcqWf6BL-mfTSNqDq3-e-CDa0N1SXyiQ'}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList61', 'sec_Addon_Widgets', document.getElementById('LinkList61'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList62', 'sec_Addon_Widgets', document.getElementById('LinkList62'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_LinkListView', new _WidgetInfo('LinkList63', 'sec_Addon_Widgets', document.getElementById('LinkList63'), {}, 'displayModeFull'));
_WidgetManager._RegisterWidget('_ImageView', new _WidgetInfo('Image61', 'sec_Addon_Widgets', document.getElementById('Image61'), {'resize': false}, 'displayModeFull'));
</script>
</body>