Alexandru Vornicescu

This is a WordPress plugin.
If you want to resize images in your posts automatically so the page will load faster and use less bandwidth then this plugin can help you.
To take effect just open a post or page and all images in that post will be resized to a smaller version.
It will replace the URLs of the images that are too big with URLs of the resized images that will fit into the posts.
The plugin will keep the original copy of all image files.
Note: With version 4.3 now you can resize images in Text Widgets.
Note: The filter – “wp_make_content_images_responsive” will be deactivated because with this plugin we will not need anymore.

Resize Images In Posts

This plugin will resize images in your posts.

adamprohack

<h3>What does this plugin do?</h3>
This plugin generate image thumbnails only when site need it, when someone call function with needed size, 
and saves disk space when image is uploaded to media library. 
You don’t need to use <code>add_image_size()</code> function.
<h3>How it works?</h3>
<ol>
<li>Upload image to media library</li>
<li>Change function <code>wp_get_attachment_image_url()</code> to <code>get_otf_image_url()</code> 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", $quality = 70)
`
</code></pre>
Parameters
<ul>
<li>Required: 
*$image_id – attachment id 
***$size_name** – dynamic size name 
***$width** – image width 
***$height** – image height</li>
<li>Optional 
*$crop_mode – image crop mode 
***$mime_type** – result image mime type 
***$quality** – result image quality</li>
</ul>
Return Value
<ul>
<li>Returns an url string</li>
</ul>

Resize Images In Posts vs WP Images OTF Plugin