One Crayon

<p>Markup to Featured Image will automatically generate a featured image when you publish a post, with the intent of allowing you to publish posts with featured images from third-party clients like MarsEdit.</p>
<p>To add a featured image to your post, include one of the following markup variants in your post’s content:</p>
<pre><code><img src="/path/to/image.jpg" data-featured-image="keep" />
<img src="/path/to/image.jpg" data-featured-image="strip" />

</code></pre>
<p>If you use an <code><img></code> element, the values of the <code>data-featured-image</code> attribute specify whether the image should be displayed when the post is shown on your site (<code>keep</code>) or ignored when the post is displayed (<code>strip</code>). The order of attributes in your <code><img></code> tag (and whether you include other attributes, like width/height, title, alt, etc.) doesn’t matter. You can make it as complicated or simple as you like.</p>
<p>If the post already has a featured image, the plugin will do nothing (version 1.0 does <em>not</em> allow updating the thumbnail by updating the markup).</p>

Markup to Featured Image

Automatically set the featured image (formerly the post thumbnail) for a post based on custom markup in the body text.

finnj

<p>Frontier Set Featured will set featured image from images in the post if no featured image is set by the user.</p>
<h4>Main Features</h4>
<ul>
<li>If no Featured Images is set on save, the plugin will:
<ul>
<li>Select the first image that is uploaded to the post, and set it as Featured Image</li>
<li>If still no Featured Image, select the first image from the post content, and set it as Featured Image</li>
</ul>
</li>
<li>The will work both from admin interface & frontend.</li>
</ul>
<p>Note: Only images from the media library can be used as featured images (as per WordPress standard).</p>
<h4>Frontier plugins</h4>
<ul>
<li><a href="https://wordpress.org/plugins/frontier-post/" rel="ugc">Frontier Post</a>  – Complete frontend management of posts</li>
<li><a href="https://wordpress.org/plugins/frontier-query/" rel="ugc">Frontier Query</a>  – Display lists and groupings of posts in post/pages and widgets.</li>
<li><a href="https://wordpress.org/plugins/frontier-buttons/" rel="ugc">Frontier Buttons</a>  – Full control of tinymce toolbars and buttons buttons</li>
<li><a href="https://wordpress.org/plugins/frontier-set-featured/" rel="ugc">Frontier Set Featured </a>  – Set featured image aut. based on post images </li>
<li><a href="https://wordpress.org/plugins/frontier-restrict-media/" rel="ugc">Frontier Restrict Media </a>  – Restrict media access to users own media</li>
<li><a href="https://wordpress.org/plugins/frontier-restrict-backend/" rel="ugc">Frontier Restrict Backend </a>  – Restrict access to the backend (wp-admin)</li>
</ul>


Frontier Set Featured

Frontier Set Featured will set featured image from images in the post if no featured image is set by the user.

Markup to Featured Image vs Frontier Set Featured