Alex Mills

By default, WordPress uses the center of an image when creating cropped thumbnails. SmartCrop attempts to find and use the most interesting part of an image and centers the cropping on that portion of the image.
This process is entirely automatic and cannot be manually controlled. There are other plugins out there if you wish to manually specify where you want thumbnails to be cropped.
Since this analysis process can be slow on large images, thumbnails are initially center cropped and later asynchronously regenerated to be smartly cropped. This avoids the uploading of new images from being slow. The one side effect of this however is that your browser may load and cache the centered thumbnail before it’s re-cropped.
Want to smartly crop your past image uploads? You can use my <a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a> plugin to trigger that. Make sure to uncheck skipping existing thumbnails.
<h4>Need Help? Found A Bug? Want To Contribute Code?</h4>
Support for this plugin is provided via the <a href="https://wordpress.org/support/plugin/smartcrop" rel="ugc">WordPress.org forums</a>.
The source code for this plugin is available on <a href="https://github.com/Viper007Bond/smartcrop" rel="nofollow ugc">GitHub</a>.

SmartCrop

Instead of cropping to the center of an image, SmartCrop attempts to use the most interesting part of the image for the thumbnail.

benplum

Presswell

Presswell Art Direction helps simplify how custom image thumbnail sizes are defined, cropped, and generated.
Features
<ul>
<li>Control image cropping with hot-spots</li>
<li>Select custom image sizes in the WordPress editor</li>
<li>Dynamically generate image thumbnails</li>
<li>Delete all cached thumbnails</li>
</ul>
Image Cropping
Presswell Art Direction adds the ability to set a focal point hot-spot for all images in the media library for fine grain cropping control. Simply identify where the subject of the photo is and the plugin will crop all custom image thumbnails to ensure it stays in frame.
Thumbnail Sizes
Presswell Art Direction adds an easy to use interface for defining and editing custom image thumbnail sizes. Custom image sizes will be available for selection when inserting images in the post editor.
Dynamic Images
Presswell Art Direction prevents custom image sizes from being generated automatically. Only standard WordPress thumbnails will be generated when a new image is uploaded. All other image sizes will be dynamically generated when called via code or requested via URL, saving server space when many custom image sizes are defined. Note: URL based image generation requires that <a href="https://codex.wordpress.org/Using_Permalinks" rel="nofollow ugc">pretty permalinks</a> are enabled.
<h4>Documentation</h4>
pwad_add_image_size( $args )
<ul>
<li>$args (array) (required) – Keyed array containing <code>name</code>, <code>key</code>, <code>height</code>, <code>width</code>, and optionally <code>thumbnails</code> values; Thumbnail keys are prefixed with parent’s key like ‘[size]-[thumbnail]’</li>
</ul>
Example:
<pre><code>pwad_add_image_size( array(
 'name' => 'Square',
 'key' => 'square',
 'width' => '1200',
 'height' => '1200',
 'thumbnails' => array(
 array(
 'name' => 'Medium',
 'key' => 'medium',
 'width' => '800',
 'height' => '800',
 ),
 array(
 'name' => 'Small',
 'key' => 'small',
 'width' => '400',
 'height' => '400',
 ),
 ),
) );
</code></pre>
pwad_get_image( $attachment_ID, $size_key, $thumbnail_key )
<ul>
<li>$attachment_ID (int) (required) – ID of image attachment</li>
<li>$size_key (string) (required) – Image size identifier; Overload using ‘[size]-[thumbnail]’ pattern</li>
<li>$thumbnail_key (string) (required) – Image size thumbnail identifier</li>
</ul>
Returns an image tag.
Example:
<pre><code>$square_large = pwad_get_image( $img_ID, 'square' );
$square_medium = pwad_get_image( $img_ID, 'square', 'medium' );
$square_small = pwad_get_image( $img_ID, 'square-small' ); // Overloaded
</code></pre>
pwad_get_image_src( $attachment_ID, $size_key, $thumbnail_key )
<ul>
<li>$attachment_ID (int) (required) – ID of image attachment</li>
<li>$size_key (string) (required) – Image size identifier; Overload using ‘[size]-[thumbnail]’ pattern</li>
<li>$thumbnail_key (string) (required) – Image size thumbnail identifier</li>
</ul>
Returns a keyed array containing the <code>file</code>, <code>url</code>, <code>path</code>, <code>height</code>, <code>width</code>, and <code>mime-type</code> values.
Example:
<pre><code>$square_large = pwad_get_image_src( $img_ID, 'square' );
$square_medium = pwad_get_image_src( $img_ID, 'square', 'medium' );
$square_small = pwad_get_image_src( $img_ID, 'square-small' ); // Overloaded
</code></pre>

Presswell Art Direction

Really easy to use, and integrated perfectly with the front end of the site without any extra javascript or CSS required. Perfect add-on.

Very well done

Control how custom image thumbnail sizes are defined, cropped, and generated.

SmartCrop vs Presswell Art Direction