Classes/Service/ImageResizer.php
protected function expandConversionMapping(array $mapping)
    {
        $ret = [];
        $matches = [];
        foreach ($mapping as $m) {
            if (preg_match('/^(.*)\s*=>\s*(.*)/', $m, $matches)) {
                $ret[trim($matches[1])] = trim($matches[2]);
            }
        }
        return $ret;
    }
protected function expandConversionMapping(array $mapping)
    {
        $ret = [];
        $matches = [];
        foreach ($mapping as $m) {
            if (preg_match('/^(.*)\s*=>\s*(.*)/', $m, $matches)) {
                $ret[trim($matches[1])] = trim($matches[2]);
            }
        }
        return $ret;
    }
Expands the image type conversion mapping.

@param array $mapping Array of lines similar to "bmp => jpg", "tif => jpg"
@return array Key/Value pairs of mapping: array('bmp' => 'jpg', 'tif' => 'jpg')