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.

Tomasz Sita

<p>Plugin allows you to manually crop all the image sizes registered in your WordPress theme (in particular featured image).<br />
Simply click on the “Crop” link next to any image in your media library.<br />
The WordPress Media Modal interface will be brought up and you are ready to go.<br />
Whole cropping process is really intuitive and simple.</p>
<p>Apart from media library list, the plugin adds links in few more places:<br />
* Below featured image box (“Crop featured image”)<br />
* In the media insert modal window (once you select an image)</p>
<h4>Settings</h4>
<p>The plugin includes a settings page where you can configure:<br />
* Image quality settings<br />
* Visibility of crop options<br />
* Custom labels for image sizes</p>
<h4>GitHub Repository</h4>
<p>https://github.com/tomaszsita/wp-manual-image-crop</p>
<h4>Translations</h4>
<ul>
<li>Czech (AI Generated)</li>
<li>Dutch (Bernardo Hulsman)</li>
<li>French (Gabriel Féron)</li>
<li>German (Bertram Greenhough)</li>
<li>Hungarian (Roland Kal)</li>
<li>Italian (Alessandro Curci)</li>
<li>Japanese (AI Generated)</li>
<li>Korean (AI Generated)</li>
<li>Polish (myself)</li>
<li>Portuguese (Brazil) (AI Generated)</li>
<li>Russian (Andrey Hohlov)</li>
<li>Spanish (Andrew Kurtis)</li>
<li>Swedish (Karl Oskar Mattsson)</li>
<li>Turkish (AI Generated)</li>
</ul>
<p>Please contact me if you want to add a translation (or submit a pull request on GitHub)</p>


Manual Image Crop

Doesn't seem to work with add_image_size when used with a child theme's function.php using code like below:
/*---------------------------------------------*/
/* ADD CUSTOM IMAGE SIZES
/*---------------------------------------------*/

if ( function_exists( 'add_image_size' ) ) {
	add_image_size( 'facebook-image-page', 470, 470 );
}

add_filter( 'image_size_names_choose', 'insert_custom_image_sizes' );
function insert_custom_image_sizes( $sizes ) {
	global $_wp_additional_image_sizes;
	if ( empty($_wp_additional_image_sizes) )
		return $sizes;

	foreach ( $_wp_additional_image_sizes as $id => $data ) {
		if ( !isset($sizes[$id]) )
			$sizes[$id] = ucfirst( str_replace( '-', ' ', $id ) );
	}

	return $sizes;
}


Doesn't seem to work with

Support for this plug-in is very bad and it contains a few bugs. No response after a month..

Abandoned

Plugin allows you to manually crop all the image sizes registered in your WordPress theme (in particular featured image).

Markup to Featured Image vs Manual Image Crop