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.

Matt Cromwell

fooplugins

<p>A simple gallery with one really cool feature: ZOOM!</p>
<p>A custom template for FooGallery which allows your visitors to magnify your images with a magnifying glass-like effect.</p>
<p>Like other FooGallery templates you can customize the image size, border styles and shapes. With ZOOM! You can also customize the lens size, lens border, shadow depth. You can also set your thumbnails to have a grayscale or blurred effect either on load or on hover. Blur/grayscale only effects the thumbnail, so that when you look through the magnifying glass you still have a sharp, crisp, and full-color image magnified.</p>
<h3>Useful Resources</h3>
<ul>
<li><a href="https://wordpress.org/plugins/foogallery/" rel="ugc">Download FooGallery</a></li>
<li><a href="https://github.com/fooplugins/foogallery" rel="nofollow ugc">Contribute to FooGallery on Github</a></li>
<li><a href="https://wordpress.org/plugins/foogallery-owl-carousel-template/" rel="ugc">Check out my other template: Owl Carousel</a></li>
<li><a href="http://mattcromwell.com" rel="nofollow ugc">Found out more about Matt Cromwell, author of this plugin</a></li>
</ul>


FooGallery ZOOM Template

A simple gallery with one really cool feature: ZOOM!

Grayscale vs FooGallery ZOOM Template