What could be causing the "Fatal error: Out of memory" issue during image upload in PHP?

The "Fatal error: Out of memory" issue during image upload in PHP occurs when the script tries to allocate more memory than the limit set in the php.ini file. To solve this issue, you can increase the memory limit in the php.ini file or adjust it dynamically within your PHP script using the ini_set() function.

// Increase memory limit in PHP script
ini_set('memory_limit', '256M');