Generating images in php requires the use of a GD library. By default, phpStudy is turned on. However, after phpStudy2013, the GD library is installed by default and no longer enables this function. Users need to configure it. .
phpStudy2013 GD support is not enabled. Solution
phpStudyAdmin Console - Configuration File - php.ini
Look for "extension=php_gd2.dll", remove the ";" in front of "extension=php_gd2.dll", and save
phpStudyAdmin Console - Apache Service - Restart