Thank you very much Master,
There was a conflict with the plugin sef_url (removed).
Working perfectly 100%, first script you created,
hereThis htaccess file is ready for redirect.php script, as follows:
<Files ".htaccess">
Order Allow,Deny
Deny from All
</Files>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -f
RewriteCond %{REQUEST_FILENAME} \.([Bb][Mm][Pp]|[Jj][Pp][Ee]?[Gg]|[Gg][Ii][Ff]|[Pp][Nn][Gg])$ [NC]
<FilesMatch "^(normal_(.*)|thumb_(.*)).([Bb][Mm][Pp]|[Jj][Pp][Ee]?[Gg]|[Gg][Ii][Ff]|[Pp][Nn][Gg])$">
RewriteCond %{HTTP_REFERER} !^$
</FilesMatch>
RewriteCond %{HTTP_REFERER} !^http(s)?://(.*)?example.com [NC]
RewriteCond %{REQUEST_URI} !^/example\.jpg$ [NC]
RewriteRule ^(.*\.([Bb][Mm][Pp]|[Jj][Pp][Ee]?[Gg]|[Gg][Ii][Ff]|[Pp][Nn][Gg]))$ http://example.com/redirect.php?$1 [R,NC,L]
RewriteCond %{REQUEST_FILENAME} -f
RewriteCond %{REQUEST_FILENAME} \.(7z|aac|arj|as(f|x)|avi|bz2|divx|docx?|f4(a|v)|flv|gtar|gz|lzh|m4(a|v)|midi?|mkv|mov(ie)|mp(2|3|4|e?g)|og(g|m)|pdf|qt|ra(m|r)|sw(c|f)|tar|tgz|wm(a|v)|zip)$ [NC]
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(.*)?example.com [NC]
RewriteRule ^(.*\.(7z|aac|arj|as(f|x)|avi|bz2|divx|docx?|f4(a|v)|flv|gtar|gz|lzh|m4(a|v)|midi?|mkv|mov(ie)|mp(2|3|4|e?g)|og(g|m)|pdf|qt|ra(m|r)|sw(c|f)|tar|tgz|wm(a|v)|zip))$ http://example.com/redirect.php?$1 [R,NC,L]
Note: To be used in the root folder. Do not forget to replace example.com with your domain and example.jpg your image to redirect.
This other htaccess file does not work with redirect.php, is a different file (free choice, what each one likes).
Regards.