private function validateCommand($commandString)
    {
        $cmdParts = explode(" ", $commandString);

        if (count($cmdParts) < 2) {
            throw new InvalidArgumentException("This command isn't properly structured : '" . $commandString . "'");
        }

        $binaryPath = $cmdParts[0];
        $binaryPathParts = explode('/', $binaryPath);
        $binary = $binaryPathParts[count($binaryPathParts)-1];

        if (!in_array($binary, $this->_acceptedBinaries)) {
            throw new InvalidArgumentException("This command isn't part of the ImageMagick command line tools : '" . $binary . "'");
        }

        return true;
    }