A lot of people will continue to use Joomla 3 for some time, yet they want to use WebP images.
This is a small adjustment to let extensions like media manager accomplish that. Our extensions are using the J4 WebP support for resizing and stuff, and this would be good to offer WebP for all the J3 people still around.

Pull Request for Issue # .

Summary of Changes

webp Support in Image.php

Testing Instructions

$fullpath = 'path/to/image.webp';
$fullpath_resized = 'path/to/image_resized.webp';

try {
    $image = new Image($fullpath);
} catch (Exception $e) {
    return false;
}

$properties = $image->getImageFileProperties($fullpath);

switch ($properties->mime) {
    case 'image/webp':
        $imageType = \IMAGETYPE_WEBP;
        break;
    case 'image/png':
        $imageType = \IMAGETYPE_PNG;
        break;
    case 'image/gif':
        $imageType = \IMAGETYPE_GIF;
        break;
    default:
        $imageType = \IMAGETYPE_JPEG;
}

$image = $image->cropResize(1024, 768);
$image->toFile($fullpath_resized, $imageType, ['quality' => 85]);

Actual result BEFORE applying this Pull Request

Attempting to load an image of unsupported type WebP

Expected result AFTER applying this Pull Request

Successful handling of WebP images

Documentation Changes Required