Classes/Service/ImageResizer.php
public function getAllFileTypes()
    {
        $fileTypes = [];
        foreach ($this->rulesets as $ruleset) {
            if (is_array($ruleset['file_types'])) {
                $fileTypes = array_merge($fileTypes, $ruleset['file_types']);
            }
        }
        $fileTypes = array_unique($fileTypes);
        return $fileTypes;
    }
public function getAllFileTypes()
    {
        $fileTypes = [];
        foreach ($this->rulesets as $ruleset) {
            if (is_array($ruleset['file_types'])) {
                $fileTypes = array_merge($fileTypes, $ruleset['file_types']);
            }
        }
        $fileTypes = array_unique($fileTypes);
        return $fileTypes;
    }
Returns all file types found in the various rulesets.

@return array