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.

jojoee

<p>Automatically turn the site to grayscale (may be used for some purpose)</p>
<p>Features:</p>
<ul>
<li>Grayscale / Color switcher (for non-IE)</li>
<li>Theme option to enable / disable switcher and select switcher position</li>
<li>Default mode, ability to set default which either “grayscale” or “color”</li>
<li>Ignored Post IDs, user can display this plugin for specific posts by post IDs</li>
<li>Custom css</li>
</ul>
<p>Compatible with all browsers:</p>
<ul>
<li><a href="https://www.google.com/chrome/" rel="nofollow ugc">Google Chrome</a> 19+</li>
<li><a href="https://www.mozilla.org/firefox/" rel="nofollow ugc">Mozilla Firefox</a> 3.5+</li>
<li><a href="http://www.apple.com/safari/" rel="nofollow ugc">Safari</a> 6+</li>
<li><a href="https://www.microsoft.com/en-us/download/internet-explorer.aspx" rel="nofollow ugc">Internet Explorer</a> 8-9</li>
<li><a href="http://www.opera.com/" rel="nofollow ugc">Opera</a> 11.5</li>
</ul>
<h3>Notes</h3>
<ul>
<li><a href="https://codex.wordpress.org/WordPress_Coding_Standards" rel="nofollow ugc">WordPress Coding Standards</a></li>
<li>2 spaces for indent</li>
<li><a href="https://github.com/jojoee/grayscale-body" rel="nofollow ugc">Repository on Github</a></li>
</ul>
<h4>TODO</h4>
<ul>
<li>[x] Switcher</li>
<li>[x] Theme option</li>
<li>[ ] Localization</li>
<li>[ ] Separate utility out of main plugin file</li>
<li>[ ] Using the feature from <a href="https://github.com/jojoee/grayscale-body-js" rel="nofollow ugc">grayscale-body-js</a> instead</li>
</ul>
<h4>Thank you</h4>
<ul>
<li><a href="https://wordpress.org/plugins/about/validator/" rel="ugc">WordPress Plugin readme.txt Validator</a></li>
<li><a href="https://autoprefixer.github.io/" rel="nofollow ugc">Autoprefixer CSS online</a></li>
<li><a href="https://tinypng.com/" rel="nofollow ugc">TinyPNG</a></li>
<li><a href="https://www.piliapp.com/php-syntax-check/" rel="nofollow ugc">PHP code syntax check</a></li>
</ul>


Grayscale Body

Nice

Automatically turn the site to grayscale (may be used for some purpose)

Grayscale vs Grayscale Body