Fabien Quatravaux

<p>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.<br />
This plugin will make it possible without the need to manualy create the grayscale variant of each picture.</p>
<p>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 :</p>
<pre><code>the_post_thumbnail('custom_size-gray')
</code></pre>
<p>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.</p>
<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.

eng.hanan

<p>This plugin convert your website to full greyscale colors.<br />
It’s suitable for those who work on govermental websites<br />
who usually changes appearance according to public events,<br />
so in case of a tragedic event and you want your website to show your mourning you can convert your whole website into greyscale with one click.<br />
also suitable for those who just wanna have fun with their websites, so Enjoy it..</p>
<h3>Info</h3>
<p>this plugin works perfectly on all browsers except for IE</p>


1Click Grey Mode

This plugin convert your website to full greyscale colors.

Grayscale vs 1Click Grey Mode