Apache .htaccess rewrite rules to NGINX converted rules not effective
The rewrite rule convertors are quite bad usually. It is better to implement then in native nginx way. In this case, the image location would be as follows:
location ~ ^/image/([^/]+)/([^/]+)/([^/]+)/([^/]+)$ {
try_files /image.php?t=$1&w=$2&h=$3&src=$4 =404;
}
BTW. I hope your image.php has proper input validation for width / height, so that attacker cannot DDoS your server by asking 1M x 1M version of an image...