$numberOfTrainImagesToGenerate = $amount;
$logAfterEveryNumberOfCaptchas = 1000;
$captcha = new SimpleCaptcha();
$captcha->folderTrain = $folder;
$captcha->minWordLength = 6;
$captcha->maxWordLength = 6;
//empty the folder first
echo "Deleting old files...\n";
flush();
ob_flush();
flush();
exec("rm -rf {$folder}");
exec("mkdir {$folder}");
for ($j = 0; $j < $numberOfTrainImagesToGenerate; $j++) {
    // Image generation
    $captcha->CreateTrainImage();
    if ($j % $logAfterEveryNumberOfCaptchas == 0) {
        echo $j . " Training Samples have been created...(" . $captcha->skippedDuplicates . " skipped duplicates)\n";
        flush();
        ob_flush();
        flush();
        //ob_flush();flush();
        $captcha->skippedDuplicates = 0;
    }
}
echo $j . " Training Samples have been created...\n";
flush();
ob_flush();
flush();
/**
 * SimpleCaptcha class