adamprohack

<h3>What does this plugin do?</h3>
<p>This plugin generate image thumbnails only when site need it, when someone call function with needed size,<br />
and saves disk space when image is uploaded to media library.<br />
You don’t need to use <strong><code>add_image_size()</code></strong> function.</p>
<h3>How it works?</h3>
<ol>
<li>Upload image to media library</li>
<li>Change function <strong><code>wp_get_attachment_image_url()</code></strong> to <strong><code>get_otf_image_url()</code></strong> in your wordpress template</li>
<li>When function is invoke the first time, the image is dynamically adjust, create and stored</li>
<li>Page serve image in need size</li>
</ol>
<h3>Documentation</h3>
<pre><code>`php
function get_otf_image_url(
    $image_id, $size_name, 
    $width = 0, $height = 0, 
    $crop_mode = ["center", "center"], 
    $mime_type = "image/jpeg", $quality = 70)
`
</code></pre>
<p><strong>Parameters</strong></p>
<ul>
<li>Required:<br />
*<strong>$image_id</strong>  – attachment id<br />
***$size_name** – dynamic size name<br />
***$width** – image width<br />
***$height** – image height</li>
<li>Optional<br />
*<strong>$crop_mode</strong> – image crop mode<br />
***$mime_type** – result image mime type<br />
***$quality** – result image quality</li>
</ul>
<p><strong>Return Value</strong></p>
<ul>
<li>Returns an url string</li>
</ul>


WP Images OTF Plugin

Human Made

Joe Hoyle

Matthew Haines-Young

tcrsavage

Tom Willmot

<p>WP Thumb is a simple plugin that seamlessly integrates with the WordPress image functions. You can specify height, width and crop values, and an image will be generated, which is then cached for future use.</p>
<h4>Features</h4>
<ul>
<li>Automatic images resizing, cropping and caching.</li>
<li>Ideal for when you want to change the dimensions of default image sizes.</li>
<li>Can extend using filters to make use of any of the phpThumb Library functions by manipulating the image object.</li>
</ul>
<h3>Contribution guidelines</h3>
<p>see https://github.com/humanmade/WPThumb/blob/master/CONTRIBUTING.md</p>


WPThumb

An on-demand image generation replacement for WordPress' image resizing.

WP Images OTF Plugin vs WPThumb