How to refer to index.php when there is no image?

Question

PHP

Hello.
Tell me what you need to attribute to refer to the index.php file when the image does not exist.
For example, on request site.ru/images/798456754.jpg , picture
A opens on request site.ru/images/6547626645.jpg and there is no such picture, index.php is launched.
Current htaccess

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php

Answer 1

as an option - in the 404 error handler (the page that you have now instead of the erroneous address), set the referrer check. if its address ends with jpg/png/gif - put a 301 redirect to index.php.