CImage.php
private function normalizeFileExtension($extension = null)
    {
        $extension = strtolower($extension ? $extension : $this->extension);

        if ($extension == 'jpeg') {
                $extension = 'jpg';
        }

        return $extension;
    }
private function normalizeFileExtension($extension = null)
    {
        $extension = strtolower($extension ? $extension : $this->extension);

        if ($extension == 'jpeg') {
                $extension = 'jpg';
        }

        return $extension;
    }
private function normalizeFileExtension ( $ extension = null ) { $ extension = strtolower ( $ extension ? $ extension : $ this -> extension ) ; if ( $ extension == 'jpeg' ) { $ extension = 'jpg' ; } return $ extension ; }
Normalize the file extension.

@param string $extension of image file or skip to use internal.

@return string $extension as a normalized file extension.
Normalize the file extension .