Fabien Quatravaux

Sometimes, your website design requires to turn pictures in black & white : for example in a gallery display, you can have all thumbnails in grayscale and bring up colors when the mouse is hovering it. 
This plugin will make it possible without the need to manualy create the grayscale variant of each picture.
In your theme’s <code>functions.php</code>, instead of using WP <a href="https://codex.wordpress.org/Function_Reference/add_image_size" rel="nofollow ugc">add_image_size</a> function, use <code>grayscale_add_image_size('custom_size', xxx, yyy, $crop, $grayscale)</code> (with <code>$crop</code> set to <code>true</code> if you want to crop the image, and <code>$grayscale</code> set to <code>true</code> if you want a grayscale version of the image). Then, you can use <a href="https://codex.wordpress.org/Function_Reference/the_post_thumbnail" rel="nofollow ugc">the_post_thumbnail</a> or any thumbnail function to get your grayscale image :
<pre><code>the_post_thumbnail('custom_size-gray')
</code></pre>
A gamma correction is applied automatically to make the black & white pictures look good. From version 1.2, You can tune this gamma correction with the <code>grayscale_gamma_correction</code> filter. Your filter would have to return a float number that will be use as the <code>outputgamma</code> parameter of the <a href="http://php.net/manual/fr/function.imagegammacorrect.php" rel="nofollow ugc">imagegammacorrect</a> function.
<h4>Known bugs</h4>
<ul>
<li>Grayscale images are not generated when the original image size is smaller than the specified thumbnail size.</li>
</ul>

Grayscale

Automatically create grayscale thumbnails for a given image size.

REALMEDIA.IL

Real Accessability plugin adds very easy to use & intuitive accessability toolbar to your website.
Real Accessability Features:
<ul>
<li>Increase font/text size</li>
<li>Decrease font/text size</li>
<li>Turn Black&White view</li>
<li>Invert website colors</li>
<li>Highlight all links with underline</li>
<li>Use more readable font (Arial)</li>
<li>Remove target attribute</li>
<li>Add role=”link” to links</li>
<li>RTL & LTR Support</li>
</ul>
Available languages:
<ul>
<li>English</li>
<li>Hebrew</li>
</ul>

Real Accessability

works great!

Real Accessability plugin adds custom accessability such as font resizer, color inverse, black & white view and much more

Grayscale vs Real Accessability